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+
+
+
+
+
+
+From VMS to Linux HOWTO
+
+By Guido Gonzato, �,
+and Mike Miller, �
+
+v1.1.4, 22 September 2004
+
+
+
+
+This HOWTO is aimed at all those who have been using VMS and now need or
+want to switch to Linux, the free UNIX clone. The transition is made
+(hopefully) painless with a step--to--step comparison between commands and
+available tools.
+
+
+
+
+
+
+
+Introduction
+
+
+Why Linux?
+
+
+You've heard that UNIX is difficult and balk at the prospect of leaving VMS,
+don't you? Don't worry. Linux, one of the finest UNIX clones, is not more
+difficult to use than VMS; actually, I find it easier. Although VMS
+aficionados may not agree, in many people's opinion Linux is much more
+powerful and versatile.
+
+
+
+Linux and VMS are both good operating systems and accomplish essentially the
+same tasks, but Linux has a few features that make it a good alternative to
+VMS. Moreover, Linux is available for PCs while VMS is not, and modern
+Pentium-based Linux machines can outperform a VAX. The icing on the cake is
+the excellent performance of modern video cards, which turn an X11-based
+Linux box into a fast graphic workstation; nearly always, quicker than
+dedicated machines.
+
+
+
+I imagine you're a university researcher or a student, and that you use
+VMS for the following everyday tasks:
+
+
+
+
+
+
+
+
+ writing papers with TeX/LaTeX;
+
+
+
+
+
+ programming in Fortran;
+
+
+
+
+
+ doing some graphics;
+
+
+
+
+
+ using Internet services;
+
+
+
+
+
+ et cetera.
+
+
+
+
+
+
+
+
+
+In the following sections I'm going to explain to you how to do these
+tasks under Linux, exploiting your experience with VMS. Prerequisites:
+
+
+
+
+
+
+
+
+ Linux and X Window System are properly installed;
+
+
+
+
+
+
+ there's a system administrator to take care of the technical
+details (please get help from them, not from me ;-) ;
+
+
+
+
+
+
+ your shell---the equivalent of DCL---is bash (ask your
+sysadm).
+
+
+
+
+
+
+
+
+
+Please note that this HOWTO is not enough to acquaint you fully with
+Linux: it only contains the bare essential to get you started. You
+should learn more about Linux to make the most of it (advanced bash
+features, programming, regular expressions...). From now on, RMP means
+`please read the man pages for further details'. The man pages are the
+equivalent of the command HELP.
+
+
+
+The Linux Documentation Project documents, available on �, are an important source of
+information. I suggest that you read Larry Greenfield's ``Linux User
+Guide''---it's invaluable for the novice user.
+
+
+
+And now, go ahead.
+
+
+
+
+
+Comparing Commands and Files
+
+
+This table attempts to compare VMS' and Linux' most used commands. Please
+keep in mind that the syntax is often very different; for more details,
+refer to the following sections.
+
+
+
+
+
+VMS Linux Notes
+------------------------------------------------------------------------------
+
+@COMMAND command must be executable
+COPY file1 file2 cp file1 file2
+CREATE/DIR [.dirname] mkdir dirname only one at a time
+CREATE/DIR [.dir1.dir2] mkdirhier dir/name
+DELETE filename rm filename
+DIFF file1 file2 diff -c file1 file2
+DIRECTORY ls
+DIRECTORY [...]file find . -name file
+DIRECTORY/FULL ls -al
+EDIT filename vi filename, you won't like it
+ emacs filename, EDT compatible
+ jed filename ditto---my favourite
+FORTRAN prog.for g77 prog.f, no need to do LINK
+ f77 prog.f,
+ fort77 prog.f
+HELP command man command must specify `command'
+ info command ditto
+LATEX file.tex latex file.tex
+LOGIN.COM .bash_profile, `hidden' file
+ .bashrc ditto
+LOGOUT.COM .bash_logout ditto
+MAIL mail, crude
+ elm, much better
+ pine better still
+ mutt ditto
+PRINT file.ps lpr file.ps
+PRINT/QUEUE=laser file.ps lpr -Plaser file.ps
+PHONE user talk user
+RENAME file1 file2 mv file1 file2 not for multiple files
+RUN progname progname
+SEARCH file "pattern" grep pattern file
+SET DEFAULT [-] cd ..
+SET DEFAULT [.dir.name] cd dir/name
+SET HOST hostname telnet hostname, not exactly the same
+ rlogin hostname
+SET FILE/OWNER_UIC=joe chown joe file completely different
+SET NOBROADCAST mesg
+SET PASSWORD passwd
+SET PROT=(perm) file chmod perm file completely different
+SET TERMINAL export TERM= different syntax
+SHOW DEFAULT pwd
+SHOW DEVICE du, df
+SHOW ENTRY lpq
+SHOW PROCESS ps -ax
+SHOW QUEUE lpq
+SHOW SYSTEM top
+SHOW TIME date
+SHOW USERS w
+STOP kill
+STOP/QUEUE kill, for processes
+ lprm for print queues
+SUBMIT command command &
+SUBMIT/AFTER=time command at time command
+TEX file.tex tex file.tex
+TYPE/PAGE file more file
+ less file much better
+
+
+
+
+
+
+But of course it's not only a matter of different command names. Read on.
+
+
+
+
+
+
+
+Short Intro
+
+
+This is what you absolutely need to know before logging in the first
+time. Relax, it's not much.
+
+
+
+Files
+
+
+
+
+
+
+
+ Under VMS filenames are in the form filename.extension;version.
+Under Linux, the version number doesn't exist (big limitation, but see
+Section ); the filename
+has normally a limit of 255 characters and can have as many dots as you
+like. Example of filename: This.is_a_FILEname.txt.
+
+
+
+
+
+
+ Linux distinguishes between upper case and lower case characters:
+FILENAME.txt and filename.txt are two different files;
+ls is a command, LS is not.
+
+
+
+
+
+
+ A filename starting with a dot is a `hidden' file (that is,
+it won't normally show up in dir listings), while filenames ending with a
+tilde '˜' represent backup files.
+
+
+
+
+
+
+
+
+
+
+Now, a table to sum up how to translate commands from VMS to Linux:
+
+
+
+
+
+
+VMS Linux
+---------------------------------------------------------------------
+
+$ COPY file1.txt file2.txt $ cp file1.txt file2.txt
+$ COPY [.dir]file.txt [] $ cp dir/file.txt .
+$ COPY [.dir]file.txt [-] $ cp dir/file.txt ..
+$ DELETE *.dat;* $ rm *dat
+$ DIFF file1 file2 $ diff -c file1 file2
+$ PRINT file $ lpr file
+$ PRINT/queue=queuename file $ lpr -Pprintername file
+$ SEARCH *.tex;* "geology" $ grep geology *tex
+
+
+
+
+
+For other examples involving directories, see below; for details about
+protections, ownership, and advanced topics, see Section .
+
+
+
+
+
+Directories
+
+
+
+
+
+
+
+ Within the same node and device, directories names under VMS are in
+the form [top.dir.subdir]; under Linux, /top/dir/subdir/. On
+the top of the directory tree lies the so--called `root directory' called
+/; underneath there are other directories like /bin,
+/usr, /tmp, /etc, and others.
+
+
+
+
+
+
+ The directory /home contains the so--called users' `home
+directories': e.g. /home/guido, /home/warner, and so on.
+When a user logs in, they start working in their home dir; it's the
+equivalent of SYS$LOGIN. There's a shortcut for the home
+directory: the tilde '˜'. So, cd ˜/tmp is the same
+as, say, cd /home/guido/tmp.
+
+
+
+
+
+
+ Directory names follow the same rules as file names. Furthermore,
+each directory has two special entries: one is . and refers to the
+directory itself (like []), and .. that refers to the parent
+directory (like [-]).
+
+
+
+
+
+
+
+
+
+And now for some other examples:
+
+
+
+
+
+
+VMS Linux
+---------------------------------------------------------------------
+
+$ CREATE/DIR [.dirname] $ mkdir dirname
+$ CREATE/DIR [.dir1.dir2.dir3] $ mkdirhier dir1/dir2/dir3
+ n/a $ rmdir dirname
+ (if dirname is empty)
+ $ rm -R dirname
+$ DIRECTORY $ ls
+$ DIRECTORY [...]file.*;* $ find . -name "file*"
+$ SET DEF SYS$LOGIN $ cd
+$ SET DEF [-] $ cd ..
+$ SET DEF [top.dir.subdir] $ cd /top/dir/subdir
+$ SET DEF [.dir.subdir] $ cd dir/subdir
+$ SHOW DEF $ pwd
+
+
+
+
+
+
+For protections, ownership, and advanced topics, see Section .
+
+
+
+
+
+Programs
+
+
+
+
+
+
+
+ Commands, compiled programs, and shell scripts (VMS' `command
+files') don't have sort of mandatory extensions like .EXE or .COM
+and can be called whatever you like. Executable files are marked by an
+asterisk '*' when you issue ls -F.
+
+
+
+
+
+
+ To run an executable file, just type its name (no RUN
+PROGRAM.EXE or @COMMAND). Caveat: it's essential that the file be
+located in a directory included in the path of executables, which is a
+list of directories. Typically, the path includes dirs like /bin,
+/usr/bin, /usr/X11R6/bin, and others. If you write your
+own programs, put them in a directory you have included in the path (see how
+in Section ). As an alternative,
+you may run a program specifying its complete path: e.g.,
+/home/guido/data/myprog; or ./myprog, if the current
+directory isn't in the path.
+
+
+
+
+
+
+ Command switches are obtained with /OPTION= under VMS, and
+with -switch or --switch under Linux, where switch is a
+letter, more letters combined, or a word. In particular, the switch -R
+(recursive) of many Linux commands performs the same action as [...]
+under VMS;
+
+
+
+
+
+
+ You can issue several commands on the command line:
+
+
+
+$ command1 ; command2 ; ... ; commandn
+
+
+
+
+
+
+
+
+ Most of the flexibility of Linux comes from two features awkwardly
+implemented or missing in VMS: I/O redirection and piping. (I have been told
+that recent versions of DCL support redirection and piping, but I don't have
+that version.) Redirection is a side feature under VMS (remember
+the switch /OUTPUT= of many commands), or a fastidious process,
+like:
+
+
+
+$ DEFINE /USER SYS$OUTPUT OUT
+$ DEFINE /USER SYS$INPUT IN
+$ RUN PROG
+
+
+
+which has the simple Linux (UNIX) equivalent:
+
+
+
+$ prog < in > out
+
+
+
+Piping is not readily available under VMS, but has a key role under UNIX. A
+typical example:
+
+
+
+$ myprog < datafile | filter_1 | filter_2 >> result.dat 2> errors.log &
+
+
+
+which means: the program myprog gets its input from the file
+datafile (via <), its output is piped (via |) to
+the program filter_1 that takes it as input and processes it, the
+resulting output is piped again to filter_2 for further processing, the
+final output is appended (via >>) to the file result.dat,
+and error messages are redirected (via 2>) onto the file
+errors.log. All this in background (& at the end of the
+command line). More about this in Section .
+
+
+
+
+
+
+
+
+
+For multitasking, `queues', and the like, see Section .
+
+
+
+
+
+Quick Tour
+
+
+Now you are ready to try Linux out. Enter your login name and password
+exactly as they are. For example, if your login name and password are
+john and My_PassWd, don't type John or my_passwd.
+Remember, UNIX distinguishes between capital and small letters.
+
+
+
+Once you've logged in, you'll see a prompt; chances are it'll be something
+like machinename:$. If you want to change the prompt or make
+some programs start automatically, you'll have to edit a `hidden' file
+called .profile or .bash_profile (see example in Section ). This is the equivalent of
+LOGIN.COM.
+
+
+
+Pressing ALT--F1, ALT--F2, ... ALT--F6 switches between `virtual consoles'.
+When one VC is busy with a full--screen application, you can flip over to
+another and continue to work. Try and log in to another VC.
+
+
+
+Now you may want to start X Window System (from now on, X). X is a graphic
+environment very similar to DECWindows---actually, the latter derives from
+the former. Type the command startx and wait a few seconds; most likely
+you'll see an open xterm or equivalent terminal emulator, and possibly
+a button bar. (It depends on how your sysadm configured your Linux box.)
+Click on the desktop (try both mouse buttons) to see a menu.
+
+
+
+While in X, to access the text mode (`console') sessions press
+CTRL--ALT--F1 ... CTRL--ALT--F6. Try it. When in console, go back to X
+pressing ALT--F7. To quit X, follow the menu instructions or press
+CTRL--ALT--BS.
+
+
+
+Type the following command to list your home dir contents, including the
+hidden files:
+
+
+
+
+
+$ ls -al
+
+
+
+
+
+Press SHIFT--PAG UP to back-scroll. Now get help about the ls command
+typing:
+
+
+
+
+
+$ man ls
+
+
+
+
+
+pressing 'q' to exit. To end the tour, type exit to quit your session.
+If now you want to turn off your PC, press CTRL--ALT--DEL and wait a few
+seconds (never switch off the PC while in Linux! You could damage the
+filesystem.)
+
+
+
+If you think you're ready to work, go ahead, but if I were you I'd jump
+to Section .
+
+
+
+
+
+
+
+Editing Files
+
+
+Linux doesn't have EDT, but there are scores of editors available. The
+only one that's guaranteed to be included in every UNIX version is
+vi---forget it, your sysadm must have installed something better.
+Probably the most popular editor is emacs, which can emulate EDT
+to a certain degree; jed is another editor that provides EDT
+emulation.
+
+
+
+These two editors are particularly useful for editing program sources, since
+they have two features unknown to EDT: syntax hilighting and automatic
+indentation. Moreover, you can compile your programs from within the editor
+(command ESC-X compile); in case of a syntax error, the cursor will be
+positioned on the offending line. I bet that you'll never want to use the
+true blue EDT again.
+
+
+
+If you have emacs: start it, then type ESC-X edt-emulation-on.
+Pressing ALT--X or ESC-X is emacs' way of issuing commands, like
+EDT's CTRL--Z. From now on, emacs acts like EDT apart from a
+few commands. Differences:
+
+
+
+
+
+
+
+
+ don't press CTRL--Z to issue commands (if you did, you stopped
+emacs. Type fg to resume it);
+
+
+
+
+
+
+ there's an extensive on-line help. Press CTRL-H ?, or CTRL-H T to
+start a tutorial;
+
+
+
+
+
+
+ to save a file, press CTRL-X CTRL-S;
+
+
+
+
+
+
+ to exit, press CTRL-X CTRL-C;
+
+
+
+
+
+
+ to insert a new file in a buffer, press CTRL-X CTRL-F, then
+CTRL-X B to switch among buffers.
+
+
+
+
+
+
+
+
+
+If you have jed: ask your sysadm to configure jed properly.
+Emulation is already on when you start it; use the normal keypad keys, and
+press CTRL--H CTRL--H or CTRL-? to get help. Commands are issued in the same
+way as emacs'. In addition, there are some handy key bindings missing
+in the original EDT; key bindings can also be tailored to your own
+taste. Ask your sysadm.
+
+
+
+In alternative, you may use another editor with a completely different
+interface. emacs in native mode is an obvious choice; another popular
+editor is joe, which can emulate other editors like emacs itself
+(being even easier to use) or the DOS editor. Invoke the editor as
+jmacs or jstar and press, respectively, CTRL-X H or CTRL-J to get
+online help. emacs and jed are much more powerful than good
+ol' EDT.
+
+
+
+
+
+TeXing
+
+
+TeX and LaTeX are identical to their VMS counterparts---only quicker :-),
+but the tools to handle the .dvi and .ps files are superior:
+
+
+
+
+
+
+
+
+ to run a TeX file through TeX, do as usual: tex file.tex;
+
+
+
+
+
+
+ to turn a .dvi file into a .ps file, type
+dvips -o filename.ps filename.dvi;
+
+
+
+
+
+
+ to visualize a .dvi file, type within an X session:
+xdvi filename.dvi &. Click on the page to magnify. This program
+is smart: if you edit and run TeX producing newer versions of the .dvi
+file, xdvi will update it automatically;
+
+
+
+
+
+
+ to visualize a .ps file, type within an X session: ghostview
+filename.ps &. Click on the page to magnify. The whole document or
+selected pages can be printed. A newer and better program is gv.
+
+
+
+
+
+
+ to print the .ps: usually the command lpr mypaper.ps will
+do, but if the PostScript printer is called, say, `ps' (ask your
+sysadm) you'll do: lpr -Pps mypaper.ps. For more information
+about print queues, go to Section .
+
+
+
+
+
+
+
+
+
+
+
+Programming
+
+
+Programming under Linux is much better: there are lots of tools that
+make programming easier and quicker. For instance, the drudgery of
+editing--saving--exiting--compiling--re-editing can be cut short by using
+editors like emacs or jed, as seen above.
+
+
+
+Fortran
+
+
+Not substantial differences here, but note that at the time of writing the
+available (free) compilers are not 100% compatible with VMS'; expect
+some minor quirks. (It's actually the VMS compiler which has non-standard
+extensions.) See /usr/doc/g77/DOC or /usr/doc/f2c/f2c.ps
+for details.
+
+
+
+Your sysadm has installed a native compiler called g77 (good but, as of
+version 0.5.21, still not perfectly compatible with DEC Fortran) or possibly
+the Fortran to C translator, f2c, and one of the front-ends that make it
+mimic a native compiler. In my experience, the package yaf77 is the
+one that provides best results.
+
+
+
+To compile a Fortran program with g77, edit the source, save it with
+extension .f, then do:
+
+
+
+
+
+$ g77 myprog.f
+
+
+
+
+
+which creates by default an executable called a.out (you don't have
+to link anything). To give the executable a different name and do some
+optimisation:
+
+
+
+
+
+$ g77 -O2 -o myprog myprog.f
+
+
+
+
+
+Beware of optimisations! Ask your sysadm to read the documentation that
+comes with the compiler and tell you if there are any problems.
+
+
+
+To compile a subroutine:
+
+
+
+
+
+$ g77 -c mysub.f
+
+
+
+
+
+This creates a file mysub.o. To link this subroutine to a program,
+you'll do
+
+
+
+
+
+$ g77 -o myprog myprog.f mysub.o
+
+
+
+
+
+If you have many external subroutines and you want to make a library, do the
+following:
+
+
+
+
+
+$ cd subroutines/
+$ cat *f >mylib.f ; g77 -c mylib.f
+
+
+
+
+
+This will create mylib.o that you can link to your programs.
+
+
+
+Finally, to link an external library called, say, libdummy.so:
+
+
+
+
+
+$ g77 -o myprog myprog.f -ldummy
+
+
+
+
+
+If you have f2c, you only have to use f77 or fort77 instead
+of g77.
+
+
+
+Another useful programming tool is make, described below.
+
+
+
+
+
+Using <Literal remap="tt">make</Literal>
+
+
+The utility make is a tool to handle the compilation of programs that
+are split into several source files. The VMS counterparts are MMS
+and MMK, which have a different syntax.
+
+
+
+Let's suppose you have source files containing your routines, file_1.f,
+file_2.f, file_3.f, and a source file of the main program that uses the
+routines, myprog.f. If you compile your program manually, whenever you
+modify one of the source files you have to figure out which file depends on
+which, which file to recompile first, and so on.
+
+
+
+Instead of getting mad, you can write a `makefile'. This is a text file
+containing the dependencies between your sources: when one is modified, only
+the ones that depend on the modified file will be recompiled.
+
+
+
+In our example, you'd write a makefile like this:
+
+
+
+
+
+
+# This is makefile
+# Press the <TAB> key where you see <TAB>!
+# It's important: don't use spaces instead.
+
+myprog: myprog.o file_1.o file_2.o file_3.o
+<TAB>g77 -o myprog myprog.o file_1.o file_2.o file_3.o
+# myprog depends on four object files
+
+myprog.o: myprog.f
+<TAB>g77 -c myprog.f
+# myprog.o depends on its source file
+
+file_1.o: file_1.f
+<TAB>g77 -c file_1.f
+# file_1.o depends on its source file
+
+file_2.o: file_2.f file_1.o
+<TAB>g77 -c file_2.f file_1.o
+# file_2.o depends on its source file and an object file
+
+file_3.o: file_3.f file_2.o
+<TAB>g77 -c file_3.f file_2.o
+# file_3.o depends on its source file and an object file
+
+# end of makefile.
+
+
+
+
+
+Save this file as Makefile and type make to compile your program;
+alternatively, save it as myprog.mak and type make -f myprog.mak.
+And of course, RMP.
+
+
+
+
+
+Shell Scripts
+
+
+Shell scripts are the equivalent of VMS' command files, and allow for very
+powerful constructs.
+
+
+
+To write a script, all you have to do is write a standard ASCII file
+containing the commands, save it, then make it executable with the
+command chmod +x <scriptfile>. To execute it, type its name.
+
+
+
+Writing scripts under bash is such a vast subject it would require a
+book by itself, and I will not delve into the topic any further. I'll just
+give you a more-or-less comprehensive and (hopefully) useful example you can
+extract some basic rules from.
+
+
+
+EXAMPLE: sample.sh
+
+
+
+
+
+#!/bin/sh
+# sample.sh
+# I am a comment
+# don't change the first line, it must be there
+echo "This system is: `uname -a`" # use the output of the command
+echo "My name is $0" # built-in variables
+echo "You gave me the following $# parameters: "$*
+echo "First parameter is: "$1
+echo -n "What's your name? " ; read your_name
+echo notice the difference: "hi $your_name" # quoting with "
+echo notice the difference: 'hi $your_name' # quoting with '
+DIRS=0 ; FILES=0
+for file in `ls .` ; do
+ if [ -d ${file} ] ; then # if file is a directory
+ DIRS=`expr $DIRS + 1` # this means DIRS = DIRS + 1
+ elif [ -f ${file} ] ; then
+ FILES=`expr $FILES + 1`
+ fi
+ case ${file} in
+ *.gif|*jpg) echo "${file}: graphic file" ;;
+ *.txt|*.tex) echo "${file}: text file" ;;
+ *.c|*.f|*.for) echo "${file}: source file" ;;
+ *) echo "${file}: generic file" ;;
+ esac
+done
+echo "there are ${DIRS} directories and ${FILES} files"
+ls | grep "ZxY--!!!WKW"
+if [ $? != 0 ] ; then # exit code of last command
+ echo "ZxY--!!!WKW not found"
+fi
+echo "enough... type 'man bash' if you want more info."
+
+
+
+
+
+
+
+
+C
+
+
+Linux is an excellent environment to program in C. Taken for granted that
+you know C, here are a couple of guidelines. To compile your standard
+hello.c you'll use the gcc compiler, which comes as part of Linux
+and has the same syntax as g77:
+
+
+
+
+
+$ gcc -O2 -o hello hello.c
+
+
+
+
+
+To link a library to a program, add the switch -l<libname>.
+For example, to link the math library and optimize do
+
+
+
+
+
+$ gcc -O2 -o mathprog mathprog.c -lm
+
+
+
+
+
+(The -l<libname> switch forces gcc to link the library
+/usr/lib/lib<libname>.a; so -lm links
+/usr/lib/libm.a).
+
+
+
+When your program is made of several source files, you'll need to use the
+utility make described above. Just use gcc and C source files in
+the makefile.
+
+
+
+You can invoke some help about the C functions, that are covered by man
+pages, section 3; for example,
+
+
+
+
+
+$ man 3 printf
+
+
+
+
+
+There are lots of libraries available out there; among the first you'll want
+to use are ncurses, to handle text mode effects, and svgalib, to
+do graphics.
+
+
+
+
+
+
+
+Graphics
+
+
+Among the scores of graphic packages available, gnuplot stands out
+for its power and ease of use. Go to X and type gnuplot, and have
+two sample data files ready: 2D-data.dat (two data per line), and
+3D-data.dat (three data per line).
+
+
+
+Examples of 2-D graphs:
+
+
+
+
+
+gnuplot> set title "my first graph"
+gnuplot> plot '2D-data.dat'
+gnuplot> plot '2D-data.dat' with linespoints
+gnuplot> plot '2D-data.dat', sin(x)
+gnuplot> plot [-5:10] '2D-data.dat'
+
+
+
+
+
+Example of 3-D graphs (each `row' of X values is followed by a blank
+line):
+
+
+
+
+
+gnuplot> set parametric ; set hidden3d ; set contour
+gnuplot> splot '3D-data.dat' using 1:2:3 with linespoints
+
+
+
+
+
+A single-column datafile (e.g., a time series) can also be plotted as a 2-D
+graph:
+
+
+
+
+
+gnuplot> plot [-5:15] '2D-data-1col.dat' with linespoints
+
+
+
+
+
+or as a 3-D graph (blank lines in the datafile, as above):
+
+
+
+
+
+gnuplot> set noparametric ; set hidden3d
+gnuplot> splot '3D-data-1col.dat' using 1 with linespoints
+
+
+
+
+
+To print a graph: if the command to print on your Postscript printer is
+lpr -Pps file.ps, issue:
+
+
+
+
+
+gnuplot> set term post
+gnuplot> set out '| lpr -Pps'
+gnuplot> replot
+
+
+
+
+
+then type set term x11 to restore. Don't get confused---the last print
+will come out only when you quit gnuplot.
+
+
+
+For more info, type help or see the examples in directory
+/usr/lib/gnuplot/demos/, if you have it.
+
+
+
+
+
+Mail and Internet Tools
+
+
+Since Internet was born on UNIX machines, you find plenty of nice and
+easy-to-use applications under Linux. Here are just some:
+
+
+
+
+
+
+
+
+ Mail: use elm or pine to handle your email; both
+programs have on-line help. For short messages, you could use mail, as
+in mail -s "hello mate" user@somewhere < msg.txt. You may like programs
+like xmail or some such.
+
+
+
+
+
+
+ Newsgroups: use tin or slrn, both very intuitive and
+self-explanatory.
+
+
+
+
+
+
+ ftp: apart from the usual character-based ftp, ask your
+sysadm to install the full-screen ncftp or a graphical ftp client like
+xftp.
+
+
+
+
+
+
+ WWW: the ubiquitous netscape, or xmosaic,
+chimera, and arena are graphical web browsers; a character-based
+one is lynx, quick and effective.
+
+
+
+
+
+
+
+
+
+
+
+Advanced Topics
+
+
+Here the game gets tough. Learn these features, then you'll be ready to say
+that you `know something about Linux' ;-)
+
+
+
+Permissions and Ownership
+
+
+Files and directories have permissions (`protections') and ownership, just
+like under VMS. If you can't run a program, or can't modify a file, or can't
+access a directory, it's because you don't have the permission to do so,
+and/or because the file doesn't belong to you. Let's have a look at the
+following example:
+
+
+
+
+
+$ ls -l /bin/ls
+-rwxr-xr-x 1 root bin 27281 Aug 15 1995 /bin/ls*
+
+
+
+
+
+The first field shows the permissions of the file ls (owner root,
+group bin). There are three types of ownership: owner, group, and others
+(similar to VMS owner, group, world), and three types of permissions:
+read, write (and delete), and execute.
+
+
+
+From left to right, - is the file type (- = ordinary file, d
+= directory, l = link, etc); rwx are the permissions for the file
+owner (read, write, execute); r-x are the permissions for the group of
+the file owner (read, execute); r-x are the permissions for all other
+users (read, execute).
+
+
+
+To change a file's permissions:
+
+
+
+
+
+$ chmod <whoXperm> <file>
+
+
+
+
+
+where who is u (user, that is owner), g (group), o (other),
+X is either + or -, perm is r (read), w (write), or
+x (execute). Examples:
+
+
+
+
+
+$ chmod u+x file
+
+
+
+
+
+this sets the execute permission for the file owner. Shortcut:
+chmod +x file.
+
+
+
+
+
+$ chmod go-wx file
+
+
+
+
+
+this removes write and execute permission for everyone except the owner.
+
+
+
+
+
+$ chmod ugo+rwx file
+
+
+
+
+
+this gives everyone read, write, and execute permission.
+
+
+
+A shorter way to refer to permissions is with numbers: rwxr-xr-x can be
+expressed as 755 (every letter corresponds to a bit: --- is 0,
+--x is 1, -w- is 2...).
+
+
+
+For a directory, rx means that you can cd to that directory, and
+w means that you can delete a file in the directory (according to the
+file's permissions, of course), or the directory itself. All this is only
+part of the matter---RMP.
+
+
+
+To change a file's owner:
+
+
+
+
+
+$ chown username file
+
+
+
+
+
+To sum up, a table:
+
+
+
+
+
+VMS Linux Notes
+------------------------------------------------------------------------------
+
+SET PROT=(O:RW) file.txt $ chmod u+rw file.txt
+ $ chmod 600 file.txt
+SET PROT=(O:RWED,W) file $ chmod u+rwx file
+ $ chmod 700 file
+SET PROT=(O:RWED,W:RE) file $ chmod 755 file
+SET PROT=(O:RW,G:RW,W) file $ chmod 660 file
+SET FILE/OWNER_UIC=JOE file $ chown joe file
+SET DIR/OWNER_UIC=JOE [.dir] $ chown joe dir/
+
+
+
+
+
+
+
+Multitasking: Processes and Jobs
+
+
+More about running programs. There are no `batch queues' under Linux as
+you're used to; multitasking is handled very differently. Again, this is
+what the typical command line looks like:
+
+
+
+
+
+$ command -s1 -s2 ... -sn par1 par2 ... parn < input > output &
+
+
+
+
+
+where -s1, ..., -sn are the program switches,
+par1, ..., parn are the program parameters.
+
+
+
+Now let's see how multitasking works. Programs, running in foreground or
+background, are called `processes'.
+
+
+
+
+
+
+
+
+ To launch a process in background:
+
+
+$ progname [-switches] [parameters] [< input] [> output] &
+[1] 234
+
+
+the shell tells you what the `job number' (the first digit; see below) and
+PID (Process IDentifier) of the process are. Each process is identified
+by its PID.
+
+
+
+
+
+
+ To see how many processes there are:
+
+
+$ ps -ax
+
+
+This will output a list of currently running processes.
+
+
+
+
+
+
+ To kill a process:
+
+
+$ kill <PID>
+
+
+You may need to kill a process when you don't know how to quit it
+the right way... ;-). Sometimes, a process will only be killed by
+one of the following:
+
+
+$ kill -15 <PID>
+$ kill -9 <PID>
+
+
+
+
+
+
+
+
+
+
+
+In addition to this, the shell allows you to stop or temporarily suspend a
+process, send a process to background, and bring a process from background
+to foreground. In this context, processes are called `jobs'.
+
+
+
+
+
+
+
+
+ To see how many jobs there are:
+
+
+$ jobs
+
+
+jobs are identified by the numbers the shell gives them, not by their PID.
+
+
+
+
+
+
+ To stop a process running in foreground:
+
+
+$ CTRL-C
+
+
+(it doesn't always work)
+
+
+
+
+
+
+ To suspend a process running in foreground:
+
+
+$ CTRL-Z
+
+
+(ditto)
+
+
+
+
+
+
+ To send a suspended process into background (it becomes a job):
+
+
+$ bg <job>
+
+
+
+
+
+
+
+
+ To bring a job to foreground:
+
+
+$ fg <job>
+
+
+
+
+
+
+
+
+ To kill a job:
+
+
+$ kill <%job>
+
+
+
+
+
+
+
+
+
+
+
+
+
+Files, Revisited
+
+
+More information about files.
+
+
+
+
+
+
+
+
+ stdin, stdout, stderr: under UNIX, every system component is
+treated as if it were a file. Commands and programs get their input from a
+`file' called stdin (standard input; usually, the keyboard), put their
+output on a `file' called stdout (usually, the screen), and error
+messages go to a `file' called stderr (usually, the screen).
+
+Using < and > you redirect input and output to a different
+file. Moreover, >> appends the output to a file instead of
+overwriting it; 2> redirects error messages (stderr); 2>&1
+redirects stderr to stdout, while 1>&2 redirects stdout to stderr.
+There's a `black hole' called /dev/null: everything redirected to
+it disappears;
+
+
+
+
+
+
+ wildcards: '*' is almost the same. Usage: * matches all
+files except the hidden ones; .* matches all hidden files; *.* matches
+only those that have a '.' in the middle, followed by other characters;
+p*r matches both `peter' and `piper'; *c* matches both `picked' and `peck'.
+'%' becomes '?'. There is another wildcard: the
+[]. Usage: [abc]* matches files starting with a, b, c;
+*[I-N,1,2,3] matches files ending with I, J, K, L, M, N, 1, 2, 3;
+
+
+
+
+
+
+ mv (RENAME) doesn't work for multiple files; that is,
+mv *.xxx *.yyy won't work;
+
+
+
+
+
+
+ use cp -i and mv -i to be warned when a file is going to
+be overwritten.
+
+
+
+
+
+
+
+
+
+
+
+Print Queues
+
+
+Your prints are queued, like under VMS. When you issue a print command, you
+may specify a printer name. Example:
+
+
+
+
+
+$ lpr file.txt # this goes to the standard printer
+$ lpr -Plaser file.ps # this goes to the printer named 'laser'
+
+
+
+
+
+To handle the print queues, you use the following commands:
+
+
+
+
+
+
+VMS Linux
+------------------------------------------------------------------------------
+
+$ PRINT file.ps $ lpr file.ps
+$ PRINT/QUEUE=laser file.ps $ lpr -Plaser file.ps
+$ SHOW QUEUE $ lpq
+$ SHOW QUEUE/QUEUE=laser $ lpq -Plaser
+$ STOP/QUEUE $ lprm <item>
+
+
+
+
+
+
+
+
+
+
+Configuring
+
+
+Your sysadm has already provided you with a number of configuration files
+like .xinitrc, .bash_profile, .inputrc, and many others. The
+ones you may want to edit are:
+
+
+
+
+
+
+
+
+ .bash_profile or .profile: read by the shell at login
+time. It's like LOGIN.COM;
+
+
+
+
+
+
+ .bash_logout: read by the shell at logout. It's like
+LOGOUT.COM;
+
+
+
+
+
+
+ .bashrc: read by non--login shells.
+
+
+
+
+
+
+ .inputrc: this file customises the key bindings and the
+behaviour of the shell.
+
+
+
+
+
+
+
+
+
+To give you an example, I'll include my .bash_profile (abridged):
+
+
+
+
+
+# $HOME/.bash_profile
+
+# don't redefine the path if not necessary
+echo $PATH | grep $LOGNAME > /dev/null
+if [ $? != 0 ]
+then
+ export PATH="$PATH:/home/$LOGNAME/bin" # add my dir to the PATH
+fi
+
+export PS1='LOGNAME:\w\$ '
+export PS2='Continued...>'
+
+# aliases
+
+alias bin="cd ~/bin" ; alias cp="cp -i" ; alias d="dir"
+alias del="delete" ; alias dir="/bin/ls $LS_OPTIONS --format=vertical"
+alias ed="jed" ; alias mv='mv -i'
+alias u="cd .." ; alias undel="undelete"
+
+# A few useful functions
+
+inst() # Install a .tar.gz archive in current directory.
+{
+ gzip -dc $1 | tar xvf -
+}
+cz() # List the contents of a .zip archive.
+{
+ unzip -l $*
+}
+ctgz() # List the contents of a .tar.gz archive.
+{
+ for file in $* ; do
+ gzip -dc ${file} | tar tf -
+ done
+}
+tgz() # Create a .tgz archive a la zip.
+{
+ name=$1 ; tar -cvf $1 ; shift
+ tar -rf ${name} $* ; gzip -S .tgz ${name}
+}
+
+
+
+
+
+And this is my .inputrc:
+
+
+
+
+
+# $HOME/.inputrc
+# Last modified: 16 January 1997.
+#
+# This file is read by bash and defines key bindings to be used by the shell;
+# what follows fixes the keys END, HOME, and DELETE, plus accented letters.
+# For more information, man readline.
+
+"\e[1~": beginning-of-line
+"\e[3~": delete-char
+"\e[4~": end-of-line
+
+set bell-style visible
+set meta-flag On
+set convert-meta Off
+set output-meta On
+set horizontal-scroll-mode On
+set show-all-if-ambiguous On
+
+# (F1 .. F5) are "\e[[A" ... "\e[[E"
+
+"\e[[A": "info "
+
+
+
+
+
+
+
+Useful Programs
+
+
+Browsing Files: <Literal remap="tt">less</Literal>
+
+
+You'll use this file browser every day, so I'll give you a couple of tips to
+use it at best. First of all, ask your sysadm to configure less so as
+it can display not only plain text files, but also compressed files,
+archives, and so on.
+
+
+
+Like recent versions of TYPE, less lets you browse files
+in both directions. It also accepts several commands that are issued
+pressing a key. The most useful are:
+
+
+
+
+
+
+
+
+ first of all, press q to leave the browser;
+
+
+
+
+
+
+ h gives you extensive help;
+
+
+
+
+
+
+ g to go to beginning of file, G to the end, number+g
+to go to line `number' (e.g. 125g), number+% to move to that
+percentage of the file;
+
+
+
+
+
+
+ /pattern searches forwards for `pattern'; n searches
+forwards for the next match; ?pattern and N search backwards;
+
+
+
+
+
+
+ m+letter marks current position (e.g. ma); '+letter go
+to the marked position.
+
+
+
+
+
+
+ :e examines a new file;
+
+
+
+
+
+
+ !command executes the shell command.
+
+
+
+
+
+
+
+
+
+
+
+Numbered Backups Under Linux
+
+
+Alas, Linux doesn't still support file version numbers, but you overcome
+this limitation in two ways. The first is to use RCS, the Revision Control
+System, which allows you to keep previous versions of a file. RCS is
+covered in ``The RCS MINI-HOWTO'' (�).
+
+
+
+The second way is to use an editor that knows how to deal with numbered
+backups; emacs and jed are OK. In emacs, add
+these lines in your .emacs:
+
+
+
+
+
+(setq version-control t)
+(setq kept-new-versions 15) ;;; or any other value
+(setq kept-old-versions 15)
+(setq backup-by-copying-when-linked t)
+(setq backup-by-copying-when-mismatch t)
+
+
+
+
+
+In jed, make sure you have version 0.98.7 or newer; the patch for
+numbered backups is available on � .
+
+
+
+
+
+Archiving: tar & gzip
+
+
+Under UNIX there are some widely used applications to archive and
+compress files. tar is used to make archives, that is collections of
+files. To make a new archive:
+
+
+
+
+
+$ tar -cvf <archive_name.tar> <file> [file...]
+
+
+
+
+
+To extract files from an archive:
+
+
+
+
+
+$ tar -xpvf <archive_name.tar> [file...]
+
+
+
+
+
+To list the contents of an archive:
+
+
+
+
+
+$ tar -tf <archive_name.tar> | less
+
+
+
+
+
+Files can be compressed to save disk space using compress, which is
+obsolete and shouldn't be used any more, or gzip:
+
+
+
+
+
+$ compress <file>
+$ gzip <file>
+
+
+
+
+
+that creates a compressed file with extension .Z (compress) or .gz
+(gzip). These programs don't make archives, but compress files
+individually. To decompress, use:
+
+
+
+
+
+$ compress -d <file.Z>
+$ gzip -d <file.gz>
+
+
+
+
+
+RMP.
+
+
+
+The unarj, zip and unzip utilities are also available. Files
+with extension .tar.gz or .tgz (archived with tar, then
+compressed with gzip) are very common in the UNIX world. Here's how to
+list the contents of a .tar.gz archive:
+
+
+
+
+
+$ tar -ztf <file.tar.gz> | less
+
+
+
+
+
+To extract the files from a .tar.gz archive:
+
+
+
+
+
+$ tar -zxf <file.tar.gz>
+
+
+
+
+
+
+
+
+
+Real Life Examples
+
+
+UNIX' core idea is that there are many simple commands that can linked
+together via piping and redirection to accomplish even really complex tasks.
+Have a look at the following examples. I'll only explain the most complex
+ones; for the others, please study the above sections and the man pages.
+
+
+
+Problem: ls is too quick and the file names fly away.
+
+
+
+Solution:
+
+
+
+
+
+$ ls | less
+
+
+
+
+
+Problem: I have a file containing a list of words. I want to sort it
+in reverse order and print it.
+
+
+
+Solution:
+
+
+
+
+
+$ cat myfile.txt | sort -r | lpr
+
+
+
+
+
+Problem: my data file has some repeated lines! How do I get rid of them?
+
+
+
+Solution:
+
+
+
+
+
+$ sort datafile.dat | uniq > newfile.dat
+
+
+
+
+
+Problem: I have a file called 'mypaper.txt' or 'mypaper.tex' or some
+such somewhere, but I don't remember where I put it. How do I find it?
+
+
+
+Solution:
+
+
+
+
+
+$ find ~ -name "mypaper*"
+
+
+
+
+
+Explanation: find is a very useful command that lists all the files
+in a directory tree (starting from ˜ in this case). Its output
+can be filtered to meet several criteria, such as -name.
+
+
+
+Problem: I have a text file containing the word 'entropy' in this
+directory, is there anything like SEARCH?
+
+
+
+Solution: yes, try
+
+
+
+
+
+$ grep -l 'entropy' *
+
+
+
+
+
+Problem: somewhere I have text files containing the word 'entropy', I'd
+like to know which and where they are. Under VMS I'd use search entropy
+[...]*.*;*, but grep can't recurse subdirectories. Now what?
+
+
+
+Solution:
+
+
+
+
+
+$ find . -exec grep -l "entropy" {} \; 2> /dev/null
+
+
+
+
+
+Explanation: find . outputs all the file names starting from the
+current directory, -exec grep -l "entropy" is an action to be
+performed on each file (represented by {}), \
+terminates the command. If you think this syntax is awful, you're right.
+
+
+
+In alternative, write the following script:
+
+
+
+
+
+#!/bin/sh
+# rgrep: recursive grep
+if [ $# != 3 ]
+then
+ echo "Usage: rgrep --switches 'pattern' 'directory'"
+ exit 1
+fi
+find $3 -name "*" -exec grep $1 $2 {} \; 2> /dev/null
+
+
+
+
+
+Explanation: grep works like search, and combining it with
+find we get the best of both worlds.
+
+
+
+Problem: I have a data file that has two header lines, then every
+line has 'n' data, not necessarily equally spaced. I want the 2nd and
+5th data value of each line. Shall I write a Fortran program...?
+
+
+
+Solution: nope. This is quicker:
+
+
+
+
+
+$ awk 'NL > 2 {print $2, "\t", $5}' datafile.dat > newfile.dat
+
+
+
+
+
+Explanation: the command awk is actually a programming language:
+for each line starting from the third in datafile.dat, print out
+the second and fifth field, separated by a tab. Learn some awk---it
+saves a lot of time.
+
+
+
+Problem: I've downloaded an FTP site's ls-lR.gz to check its
+contents. For each subdirectory, it contains a line that reads "total xxxx",
+where xxxx is size in kbytes of the dir contents. I'd like to get the grand
+total of all these xxxx values.
+
+
+
+Solution:
+
+
+
+
+
+$ zcat ls-lR.gz | awk ' $1 == "total" { i += $2 } END {print i}'
+
+
+
+
+
+Explanation: zcat outputs the contents of the .gz file and pipes
+to awk, whose man page you're kindly requested to read ;-)
+
+
+
+Problem: I've written a Fortran program, myprog, to calculate a
+parameter from a data file. I'd like to run it on hundreds of data files
+and have a list of the results, but it's a nuisance to ask each time for
+the file name. Under VMS I'd write a lengthy command file, and under Linux?
+
+
+
+Solution: a very short script. Make your program look for the data
+file 'mydata.dat' and print the result on the screen (stdout), then
+write the following script:
+
+
+
+
+
+#!/bin/sh
+# myprog.sh: run the same command on many different files
+# usage: myprog.sh *.dat
+for file in $* # for all parameters (e.g. *.dat)
+do
+ # append the file name to result.dat
+ echo -n "${file}: " >> results.dat
+ # copy current argument to mydata.dat, run myprog
+ # and append the output to results.dat
+ cp ${file} mydata.dat ; myprog >> results.dat
+done
+
+
+
+
+
+Problem: I want to replace `geology' with `geophysics' in all my
+text files. Shall I edit them all manually?
+
+
+
+Solution: nope. Write this shell script:
+
+
+
+
+
+#!/bin/sh
+# replace $1 with $2 in $*
+# usage: replace "old-pattern" "new-pattern" file [file...]
+OLD=$1 # first parameter of the script
+NEW=$2 # second parameter
+shift ; shift # discard the first 2 parameters: the next are the file names
+for file in $* # for all files given as parameters
+do
+# replace every occurrence of OLD with NEW, save on a temporary file
+ sed "s/$OLD/$NEW/g" ${file} > ${file}.new
+# rename the temporary file as the original file
+ /bin/mv ${file}.new ${file}
+done
+
+
+
+
+
+Problem: I have some data files, I don't know their length and have to
+remove their last but one and last but two lines. Er... manually?
+
+
+
+Solution: no, of course. Write this script:
+
+
+
+
+
+#!/bin/sh
+# prune.sh: removes n-1th and n-2th lines from files
+# usage: prune.sh file [file...]
+for file in $* # for every parameter
+do
+ LINES=`wc -l $file | awk '{print $1}'` # number of lines in file
+ LINES=`expr $LINES - 3` # LINES = LINES - 3
+ head -n $LINES $file > $file.new # output first LINES lines
+ tail -n 1 $file >> $file.new # append last line
+done
+
+
+
+
+
+I hope these examples whetted your appetite...
+
+
+
+
+
+Tips You Can't Do Without
+
+
+
+
+
+
+
+ Command completion: pressing <TAB> when issuing a command
+will complete the command line for you. Example: you have to type
+less this_is_a_long_name; typing in less thi<TAB>
+will suffice. (If you have other files that start with the same
+characters, supply enough characters to resolve any ambiguity.)
+
+
+
+
+
+
+ Back-scrolling: pressing SHIFT--PAG UP (the grey key) allows
+you to backscroll a few pages, depending on your PC's video memory.
+
+
+
+
+
+
+ Resetting the screen: if you happen to more or cat
+a binary file, your screen may end up full of garbage. To fix things,
+blind type reset or this sequence of characters:
+echo CTRL-V ESC c RETURN.
+
+
+
+
+
+
+ Pasting text: in console, see below; in X, click and drag to
+select the text in an xterm window, then click the middle button
+(or the two buttons together if you have a two-button mouse) to paste.
+
+
+
+
+
+
+ Using the mouse: ask your sysadm to install gpm, a mouse
+driver for the console. Click and drag to select text, then right click
+to paste the selected text. It works across different VCs.
+
+
+
+
+
+
+
+
+
+
+
+Reading VMS tapes from Linux
+
+
+(This section was written by Mike Miller)
+
+
+
+Introduction
+
+
+From time to time you may want to read tapes made on a VMS machine (or tapes
+that are made to be readable by VMS and *nix systems). In general, this is
+quite easy for DECFILES11A tapes.
+
+
+
+Although you may be reading this as part of a Linux mini-HOWTO, I believe
+that the information here is applicable to any *nix system - I've done this
+on Linux, HP, Sun and DEC *nix systems. The main platform dependences that I
+know are device names, which can differ on different systems, and the
+options to mt for specifying the device name (for example, mt -f on Linux
+and mt -t on HPUX 9).
+
+
+
+Caveat - I've only tried this with Exabyte 8mm SCSI tape drives. If you've
+read other formats (still got those 9-tracks lying around?) let me know and
+I'll add a note here.
+
+
+
+
+
+The Basics
+
+
+When reading a tape that has been made with the VMS ``copy'' command (or has
+at least been made to look like it was made with copy) all you need to know
+is there will be three files on the tape for each actual data file - a
+header, the data, and a trailer. The header and trailer are interesting in
+that they contain info on the file as it existed under VMS. The data is,
+well, the data. Each of these files can be extracted from the tape with the
+dd command. The tape can be positioned by skipping around with the mt
+command.
+
+
+
+Example: I've got VMS tape with a series of files on it. The first two were
+originally named ce66-2.evt and ce66-3.evt on a VMS system. The tape label
+is c66a2.
+
+
+
+If I execute these commands:
+
+
+
+
+
+> dd if=$TAPE bs=16k of=header1
+> dd if=$TAPE bs=16k of=data1
+> dd if=$TAPE bs=16k of=trailer1
+> dd if=$TAPE bs=16k of=header2
+> dd if=$TAPE bs=16k of=data2
+> dd if=$TAPE bs=16k of=trailer2
+
+
+
+
+
+I'm left with six files: header1, data1, trailer1, header2, data2 and
+trailer2. The syntax here is if="input file", bs="block size" and
+of="output file". TAPE is expected to be a variable containing the device
+name of your tape drive - for example, /dev/nts0 if you are using the first
+SCSI tape on Linux.
+
+
+
+If you wanted to read the second file, but not the first, you didn't care
+about the header, and you wanted to use the original file name, do this:
+
+
+
+
+
+> mt -f $TAPE fsf 4
+> dd if=$TAPE bs=16k of=ce66-2.evt
+> mt -f $TAPE fsf 1
+
+
+
+
+
+Note the 4 - skip three files for the first file on the tape and one for the
+next header. The second mt skips the second file's trailer and positions
+the tape at the beginning of the next file - the third VMS header. You can
+also use mt to skip backwards (bsf), rewind (rewind) and rewind and unload
+the tape (offline, rewoffl).
+
+
+
+
+
+Some details
+
+
+The header and trailer files contain uppercase ASCII data used by VMS to
+store file information such as block size. They also contain the file name,
+which can be handy if you want to build scripts that automate read files or
+search for a particular file. The first header on a tape volume is slightly
+different than subsequent headers.
+
+
+
+For a file that is the first file on the tape, as in header1 of the above
+example, the first four characters will be "VOL1" followed by the volume
+name. In the example, header1 starts with "VOL1C66A2". This is followed by
+a series of spaces terminated with a numeral. After that is the string
+"HDR1" which indicates that this is a file header. The characters
+immediately following the HDR1 string are the VMS file name. In in the
+example, this is "HDR1CE66-2.EVT". The next field is the volume name again.
+
+
+
+For files that are not the first file on the tape, the initial VOL1 field is
+not present. Other than that the header has the same structure as for the
+initial file. Another useful field is the 7th field, which will end with
+"DECFILES11A". This must be present on tapes that conform to the DEC
+Files11A standard.
+
+
+
+
+
+ field initial header subsequent headers
+ ===== ============= ==================
+ 1 VOL1 + volume name HDR1 + file name
+ 2 3HDR1 + file name volume name
+ 3 volume name
+
+ 6 ...DECFILES11A
+ 7 ...DECFILES11A
+
+
+
+
+
+For full details on the header and trailer format, see the DEC FILES11A
+documentation (on the orange/grey wall - ask your local VMS folks :-).
+
+
+
+
+
+Comment on Block Size
+
+
+In the example, I used a block size of 16k. On a *nix system, there is no
+block size associated with a file on disk while, under VMS, each file has a
+specific block size. That means that block size doesn't matter too much on
+the Linux end... unless it makes it hard to read the tape. If you have
+difficulty figuring out the block size and reading a tape, you can try
+setting the hardware block size on your tape drive using `mt -f $TAPE setblk
+0'. The exact form of the setblk option (and its availability) may depend
+on the version of mt, the tape drive hardware interface and on your
+particular flavor of *nix.
+
+
+
+(Thanks to Wojtek Skulski (�)
+for pointing out setblk.)
+
+
+
+
+
+
+
+The End
+
+
+Copyright
+
+
+Unless otherwise stated, Linux HOWTO documents are copyrighted by their
+respective authors. Linux HOWTO documents may be reproduced and distributed
+in whole or in part, in any medium physical or electronic, as long as this
+copyright notice is retained on all copies. Commercial redistribution is
+allowed and encouraged; however, the author would like to be notified of any
+such distributions.
+
+
+
+All translations, derivative works, or aggregate works incorporating any
+Linux HOWTO documents must be covered under this copyright notice. That is,
+you may not produce a derivative work from a HOWTO and impose additional
+restrictions on its distribution. Exceptions to these rules may be granted
+under certain conditions; please contact the Linux HOWTO coordinator at the
+address given below.
+
+
+
+In short, we wish to promote dissemination of this information through as
+many channels as possible. However, we do wish to retain copyright on the
+HOWTO documents, and would like to be notified of any plans to redistribute
+the HOWTOs.
+
+
+
+If you have questions, please contact Tim Bynum, the Linux HOWTO
+coordinator, at � via email.
+
+
+
+
+
+Disclaimer
+
+
+This work was written following the experience we had at the Settore di
+Geofisica of the Universita' di Bologna (Italy), where a VAX 4000 has been
+superseded and replaced by Linux-based Pentium PCs. Most of my colleagues
+are VMS users, and some of them have switched to Linux.
+
+
+
+``From VMS to Linux HOWTO'' was written by Guido Gonzato, �, and Mike Miller,
+� who contributed the section on reading VMS tapes.
+Many thanks to my colleagues and friends who helped me define the needs and
+habits of the average VMS user, especially to Dr. Warner Marzocchi.
+
+
+
+Please help me improve this HOWTO. I'm not a VMS expert and never will be,
+so your suggestions and bug reports are more than welcome.
+
+
+
+Enjoy,
+
+
+
+Guido =8-)
+
+
+
+
+
+
+
diff --git a/LDP/howto/linuxdoc/VMS-to-Linux-HOWTO.sgml b/LDP/howto/linuxdoc/VMS-to-Linux-HOWTO.sgml
deleted file mode 100644
index a10a2d76..00000000
--- a/LDP/howto/linuxdoc/VMS-to-Linux-HOWTO.sgml
+++ /dev/null
@@ -1,1662 +0,0 @@
-
-
-
-
-From VMS to Linux HOWTO
-
-<author>By Guido Gonzato,
-<url url="guido ``at'' ibogeo.df.unibo.it">,
-and Mike Miller,
-<url url="miller5@uiuc.edu">
-
-<date>v1.1.3, 17 September 1999
-
-<abstract>
-
-This HOWTO is aimed at all those who have been using VMS and now need or
-want to switch to Linux, the free UNIX clone. The transition is made
-(hopefully) painless with a step--to--step comparison between commands and
-available tools.
-
-</abstract>
-
-<toc>
-
-<sect> Introduction <label id="Introduction">
-
-<sect1> Why Linux?
-
-<p>
-
-You've heard that UNIX is difficult and balk at the prospect of leaving VMS,
-don't you? Don't worry. Linux, one of the finest UNIX clones, is not more
-difficult to use than VMS; actually, I find it easier. Although VMS
-aficionados may not agree, in many people's opinion Linux is much more
-powerful and versatile.
-
-Linux and VMS are both good operating systems and accomplish essentially the
-same tasks, but Linux has a few features that make it a good alternative to
-VMS. Moreover, Linux is available for PCs while VMS is not, and modern
-Pentium-based Linux machines can outperform a VAX. The icing on the cake is
-the excellent performance of modern video cards, which turn an X11-based
-Linux box into a fast graphic workstation; nearly always, quicker than
-dedicated machines.
-
-I imagine you're a university researcher or a student, and that you use
-VMS for the following everyday tasks:
-
-<itemize>
-
-<item> writing papers with TeX/LaTeX;
-<item> programming in Fortran;
-<item> doing some graphics;
-<item> using Internet services;
-<item> et cetera.
-
-</itemize>
-
-In the following sections I'm going to explain to you how to do these
-tasks under Linux, exploiting your experience with VMS. Prerequisites:
-
-<itemize>
-
-<item> Linux and X Window System are properly installed;
-
-<item> there's a system administrator to take care of the technical
-details (please get help from them, not from me ;-) ;
-
-<item> your shell---the equivalent of <tt/DCL/---is <tt/bash/ (ask your
-sysadm).
-
-</itemize>
-
-Please note that this HOWTO is not enough to acquaint you fully with
-Linux: it only contains the bare essential to get you started. You
-should learn more about Linux to make the most of it (advanced <tt/bash/
-features, programming, regular expressions...). From now on, RMP means
-`please read the man pages for further details'. The man pages are the
-equivalent of the command <tt/HELP/.
-
-The Linux Documentation Project documents, available on <url
-url="ftp://sunsite.unc.edu:/pub/Linux/docs/LDP">, are an important source of
-information. I suggest that you read Larry Greenfield's ``Linux User
-Guide''---it's invaluable for the novice user.
-
-And now, go ahead.
-
-<sect1> Comparing Commands and Files
-
-<p>
-
-This table attempts to compare VMS' and Linux' most used commands. Please
-keep in mind that the syntax is often very different; for more details,
-refer to the following sections.
-
-<tscreen><verb>
-VMS Linux Notes
-------------------------------------------------------------------------------
-
-@COMMAND command must be executable
-COPY file1 file2 cp file1 file2
-CREATE/DIR [.dirname] mkdir dirname only one at a time
-CREATE/DIR [.dir1.dir2] mkdirhier dir/name
-DELETE filename rm filename
-DIFF file1 file2 diff -c file1 file2
-DIRECTORY ls
-DIRECTORY [...]file find . -name file
-DIRECTORY/FULL ls -al
-EDIT filename vi filename, you won't like it
- emacs filename, EDT compatible
- jed filename ditto---my favourite
-FORTRAN prog.for g77 prog.f, no need to do LINK
- f77 prog.f,
- fort77 prog.f
-HELP command man command must specify `command'
- info command ditto
-LATEX file.tex latex file.tex
-LOGIN.COM .bash_profile, `hidden' file
- .bashrc ditto
-LOGOUT.COM .bash_logout ditto
-MAIL mail, crude
- elm, much better
- pine better still
-PRINT file.ps lpr file.ps
-PRINT/QUEUE=laser file.ps lpr -Plaser file.ps
-PHONE user talk user
-RENAME file1 file2 mv file1 file2 not for multiple files
-RUN progname progname
-SEARCH file "pattern" grep pattern file
-SET DEFAULT [-] cd ..
-SET DEFAULT [.dir.name] cd dir/name
-SET HOST hostname telnet hostname, not exactly the same
- rlogin hostname
-SET FILE/OWNER_UIC=joe chown joe file completely different
-SET NOBROADCAST mesg
-SET PASSWORD passwd
-SET PROT=(perm) file chmod perm file completely different
-SET TERMINAL export TERM= different syntax
-SHOW DEFAULT pwd
-SHOW DEVICE du, df
-SHOW ENTRY lpq
-SHOW PROCESS ps -ax
-SHOW QUEUE lpq
-SHOW SYSTEM top
-SHOW TIME date
-SHOW USERS w
-STOP kill
-STOP/QUEUE kill, for processes
- lprm for print queues
-SUBMIT command command &
-SUBMIT/AFTER=time command at time command
-TEX file.tex tex file.tex
-TYPE/PAGE file more file
- less file much better
-
-</verb></tscreen>
-
-But of course it's not only a matter of different command names. Read on.
-
-
-<sect> Short Intro <label id="Short Intro">
-
-<p>
-
-This is what you absolutely need to know before logging in the first
-time. Relax, it's not much.
-
-<sect1> Files
-
-<p>
-
-<itemize>
-
-<item> Under VMS filenames are in the form <tt/filename.extension;version/.
-Under Linux, the version number doesn't exist (big limitation, but see
-Section <ref id="Numbered Backups Under Linux"
-name="Numbered Backups Under Linux">); the filename
-has normally a limit of 255 characters and can have as many dots as you
-like. Example of filename: <tt/This.is_a_FILEname.txt/.
-
-<item> Linux distinguishes between upper case and lower case characters:
-<tt/FILENAME.txt/ and <tt/filename.txt/ are two different files;
-<tt/ls/ is a command, <tt/LS/ is not.
-
-<item> A filename starting with a dot is a `hidden' file (that is,
-it won't normally show up in dir listings), while filenames ending with a
-tilde '<tt/&tilde/' represent backup files.
-
-
-</itemize>
-
-Now, a table to sum up how to translate commands from VMS to Linux:
-
-<tscreen><verb>
-
-VMS Linux
----------------------------------------------------------------------
-
-$ COPY file1.txt file2.txt $ cp file1.txt file2.txt
-$ COPY [.dir]file.txt [] $ cp dir/file.txt .
-$ COPY [.dir]file.txt [-] $ cp dir/file.txt ..
-$ DELETE *.dat;* $ rm *dat
-$ DIFF file1 file2 $ diff -c file1 file2
-$ PRINT file $ lpr file
-$ PRINT/queue=queuename file $ lpr -Pprintername file
-$ SEARCH *.tex;* "geology" $ grep geology *tex
-</verb></tscreen>
-
-For other examples involving directories, see below; for details about
-protections, ownership, and advanced topics, see Section <ref id="Advanced
-Topics" name="Advanced Topics">.
-
-<sect1> Directories
-
-<p>
-
-<itemize>
-
-<item> Within the same node and device, directories names under VMS are in
-the form <tt/[top.dir.subdir]/; under Linux, <tt>/top/dir/subdir/</tt>. On
-the top of the directory tree lies the so--called `root directory' called
-<tt>/</tt>; underneath there are other directories like <tt>/bin</tt>,
-<tt>/usr</tt>, <tt>/tmp</tt>, <tt>/etc</tt>, and others.
-
-<item> The directory <tt>/home</tt> contains the so--called users' `home
-directories': e.g. <tt>/home/guido</tt>, <tt>/home/warner</tt>, and so on.
-When a user logs in, they start working in their home dir; it's the
-equivalent of <tt/SYS$LOGIN/. There's a shortcut for the home
-directory: the tilde '<tt/&tilde/'. So, <tt>cd ˜/tmp</tt> is the same
-as, say, <tt>cd /home/guido/tmp</tt>.
-
-<item> Directory names follow the same rules as file names. Furthermore,
-each directory has two special entries: one is <tt/./ and refers to the
-directory itself (like <tt/[]/), and <tt/../ that refers to the parent
-directory (like <tt/[-]/).
-
-</itemize>
-
-And now for some other examples:
-
-<tscreen><verb>
-
-VMS Linux
----------------------------------------------------------------------
-
-$ CREATE/DIR [.dirname] $ mkdir dirname
-$ CREATE/DIR [.dir1.dir2.dir3] $ mkdirhier dir1/dir2/dir3
- n/a $ rmdir dirname
- (if dirname is empty)
- $ rm -R dirname
-$ DIRECTORY $ ls
-$ DIRECTORY [...]file.*;* $ find . -name "file*"
-$ SET DEF SYS$LOGIN $ cd
-$ SET DEF [-] $ cd ..
-$ SET DEF [top.dir.subdir] $ cd /top/dir/subdir
-$ SET DEF [.dir.subdir] $ cd dir/subdir
-$ SHOW DEF $ pwd
-
-</verb></tscreen>
-
-For protections, ownership, and advanced topics, see Section <ref
-id="Advanced Topics" name="Advanced Topics">.
-
-<sect1> Programs
-
-<p>
-
-<itemize>
-
-<item> Commands, compiled programs, and shell scripts (VMS' `command
-files') don't have sort of mandatory extensions like <tt/.EXE/ or <tt/.COM/
-and can be called whatever you like. Executable files are marked by an
-asterisk '<tt/*/' when you issue <tt/ls -F/.
-
-<item> To run an executable file, just type its name (no <tt/RUN
-PROGRAM.EXE/ or <tt/@COMMAND/). Caveat: it's essential that the file be
-located in a directory included in the <em/path of executables/, which is a
-list of directories. Typically, the path includes dirs like <tt>/bin</tt>,
-<tt>/usr/bin</tt>, <tt>/usr/X11R6/bin</tt>, and others. If you write your
-own programs, put them in a directory you have included in the path (see how
-in Section <ref id="Configuring" name="Configuring">). As an alternative,
-you may run a program specifying its complete path: e.g.,
-<tt>/home/guido/data/myprog</tt>; or <tt>./myprog</tt>, if the current
-directory isn't in the path.
-
-<item> Command switches are obtained with <tt>/OPTION=</tt> under VMS, and
-with <tt/-switch/ or <tt/--switch/ under Linux, where <tt/switch/ is a
-letter, more letters combined, or a word. In particular, the switch <tt/-R/
-(recursive) of many Linux commands performs the same action as <tt/[...]/
-under VMS;
-
-<item> You can issue several commands on the command line:
-
-<tscreen><verb>
-$ command1 ; command2 ; ... ; commandn
-</verb></tscreen>
-
-<item> Most of the flexibility of Linux comes from two features awkwardly
-implemented or missing in VMS: I/O redirection and piping. (I have been told
-that recent versions of DCL support redirection and piping, but I don't have
-that version.) Redirection is a side feature under VMS (remember
-the switch <tt>/OUTPUT=</tt> of many commands), or a fastidious process,
-like:
-
-<tscreen><verb>
-$ DEFINE /USER SYS$OUTPUT OUT
-$ DEFINE /USER SYS$INPUT IN
-$ RUN PROG
-</verb></tscreen>
-
-which has the simple Linux (UNIX) equivalent:
-
-<tscreen><verb>
-$ prog < in > out
-</verb></tscreen>
-
-Piping is not readily available under VMS, but has a key role under UNIX. A
-typical example:
-
-<tscreen><verb>
-$ myprog < datafile | filter_1 | filter_2 >> result.dat 2> errors.log &
-</verb></tscreen>
-
-which means: the program <tt/myprog/ gets its input from the file
-<tt/datafile/ (via <tt/</), its output is piped (via <tt/|/) to
-the program <tt/filter_1/ that takes it as input and processes it, the
-resulting output is piped again to <tt/filter_2/ for further processing, the
-final output is appended (via <tt/>>/) to the file <tt/result.dat/,
-and error messages are redirected (via <tt/2>/) onto the file
-<tt/errors.log/. All this in background (<tt/&/ at the end of the
-command line). More about this in Section <ref id="Examples"
-name="Examples">.
-
-</itemize>
-
-For multitasking, `queues', and the like, see Section <ref id="Advanced
-Topics"name="Advanced Topics">.
-
-<sect1> Quick Tour <label id="Quick Tour">
-
-<p>
-
-Now you are ready to try Linux out. Enter your login name and password
-<em/exactly/ as they are. For example, if your login name and password are
-<tt/john/ and <tt/My_PassWd/, <em/don't/ type <tt/John/ or <tt/my_passwd/.
-Remember, UNIX distinguishes between capital and small letters.
-
-Once you've logged in, you'll see a prompt; chances are it'll be something
-like <tt/machinename:$/. If you want to change the prompt or make
-some programs start automatically, you'll have to edit a `hidden' file
-called <tt/.profile/ or <tt/.bash_profile/ (see example in Section <ref
-id="Configuring" name="Configuring">). This is the equivalent of
-<tt/LOGIN.COM/.
-
-Pressing ALT--F1, ALT--F2, ... ALT--F6 switches between `virtual consoles'.
-When one VC is busy with a full--screen application, you can flip over to
-another and continue to work. Try and log in to another VC.
-
-Now you may want to start X Window System (from now on, X). X is a graphic
-environment very similar to DECWindows---actually, the latter derives from
-the former. Type the command <tt/startx/ and wait a few seconds; most likely
-you'll see an open <tt/xterm/ or equivalent terminal emulator, and possibly
-a button bar. (It depends on how your sysadm configured your Linux box.)
-Click on the desktop (try both mouse buttons) to see a menu.
-
-While in X, to access the text mode (`console') sessions press
-CTRL--ALT--F1 ... CTRL--ALT--F6. Try it. When in console, go back to X
-pressing ALT--F7. To quit X, follow the menu instructions or press
-CTRL--ALT--BS.
-
-Type the following command to list your home dir contents, including the
-hidden files:
-
-<tscreen><verb>
-$ ls -al
-</verb></tscreen>
-
-Press SHIFT--PAG UP to back-scroll. Now get help about the <tt/ls/ command
-typing:
-
-<tscreen><verb>
-$ man ls
-</verb></tscreen>
-
-pressing 'q' to exit. To end the tour, type <tt/exit/ to quit your session.
-If now you want to turn off your PC, press CTRL--ALT--DEL and wait a few
-seconds (<em/never/ switch off the PC while in Linux! You could damage the
-filesystem.)
-
-If you think you're ready to work, go ahead, but if I were you I'd jump
-to Section <ref id="Advanced Topics"name="Advanced Topics">.
-
-
-<sect> Editing Files <label id="Editing Files">
-
-<p>
-
-Linux doesn't have <tt/EDT/, but there are scores of editors available. The
-only one that's guaranteed to be included in every UNIX version is
-<tt/vi/---forget it, your sysadm must have installed something better.
-Probably the most popular editor is <tt/emacs/, which can emulate <tt/EDT/
-to a certain degree; <tt/jed/ is another editor that provides <tt/EDT/
-emulation.
-
-These two editors are particularly useful for editing program sources, since
-they have two features unknown to <tt/EDT/: syntax hilighting and automatic
-indentation. Moreover, you can compile your programs from within the editor
-(command <tt/ESC-X compile/); in case of a syntax error, the cursor will be
-positioned on the offending line. I bet that you'll never want to use the
-true blue <tt/EDT/ again.
-
-If you have <tt/emacs/: start it, then type <tt/ESC-X edt-emulation-on/.
-Pressing ALT--X or ESC-X is <tt/emacs/' way of issuing commands, like
-<tt/EDT/'s CTRL--Z. From now on, <tt/emacs/ acts like <tt/EDT/ apart from a
-few commands. Differences:
-
-<itemize>
-
-<item> <em/don't/ press CTRL--Z to issue commands (if you did, you stopped
-<tt/emacs/. Type <tt/fg/ to resume it);
-
-<item> there's an extensive on-line help. Press CTRL-H ?, or CTRL-H T to
-start a tutorial;
-
-<item> to save a file, press CTRL-X CTRL-S;
-
-<item> to exit, press CTRL-X CTRL-C;
-
-<item> to insert a new file in a buffer, press CTRL-X CTRL-F, then
-CTRL-X B to switch among buffers.
-
-</itemize>
-
-If you have <tt/jed/: ask your sysadm to configure <tt/jed/ properly.
-Emulation is already on when you start it; use the normal keypad keys, and
-press CTRL--H CTRL--H or CTRL-? to get help. Commands are issued in the same
-way as <tt/emacs/'. In addition, there are some handy key bindings missing
-in the original <tt/EDT/; key bindings can also be tailored to your own
-taste. Ask your sysadm.
-
-In alternative, you may use another editor with a completely different
-interface. <tt/emacs/ in native mode is an obvious choice; another popular
-editor is <tt/joe/, which can emulate other editors like <tt/emacs/ itself
-(being even easier to use) or the DOS editor. Invoke the editor as
-<tt/jmacs/ or <tt/jstar/ and press, respectively, CTRL-X H or CTRL-J to get
-online help. <tt/emacs/ and <tt/jed/ are <em/much/ more powerful than good
-ol' <tt/EDT/.
-
-
-<sect> TeXing <label id="TeXing">
-
-<p>
-
-TeX and LaTeX are identical to their VMS counterparts---only quicker :-),
-but the tools to handle the <tt/.dvi/ and <tt/.ps/ files are superior:
-
-<itemize>
-
-<item> to run a TeX file through TeX, do as usual: <tt/tex file.tex/;
-
-<item> to turn a <tt/.dvi/ file into a <tt/.ps/ file, type
-<tt/dvips -o filename.ps filename.dvi/;
-
-<item> to visualize a <tt/.dvi/ file, type within an X session:
-<tt/xdvi filename.dvi &/. Click on the page to magnify. This program
-is smart: if you edit and run TeX producing newer versions of the <tt/.dvi/
-file, <tt/xdvi/ will update it automatically;
-
-<item> to visualize a <tt/.ps/ file, type within an X session: <tt/ghostview
-filename.ps &/. Click on the page to magnify. The whole document or
-selected pages can be printed. A newer and better program is <tt/gv/.
-
-<item> to print the <tt/.ps/: usually the command <tt/lpr mypaper.ps/ will
-do, but if the PostScript printer is called, say, `ps' (ask your
-sysadm) you'll do: <tt/lpr -Pps mypaper.ps/. For more information
-about print queues, go to Section <ref id="Print Queues"
-name="Print Queues">.
-
-</itemize>
-
-
-<sect> Programming <label id="Programming">
-
-<p>
-
-Programming under Linux is <em/much/ better: there are lots of tools that
-make programming easier and quicker. For instance, the drudgery of
-editing--saving--exiting--compiling--re-editing can be cut short by using
-editors like <tt/emacs/ or <tt/jed/, as seen above.
-
-<sect1> Fortran
-
-<p>
-
-Not substantial differences here, but note that at the time of writing the
-available (free) compilers are not 100% compatible with VMS'; expect
-some minor quirks. (It's actually the VMS compiler which has non-standard
-extensions.) See <tt>/usr/doc/g77/DOC</tt> or <tt>/usr/doc/f2c/f2c.ps</tt>
-for details.
-
-Your sysadm has installed a native compiler called <tt/g77/ (good but, as of
-version 0.5.21, still not perfectly compatible with DEC Fortran) or possibly
-the Fortran to C translator, <tt/f2c/, and one of the front-ends that make it
-mimic a native compiler. In my experience, the package <tt/yaf77/ is the
-one that provides best results.
-
-To compile a Fortran program with <tt/g77/, edit the source, save it with
-extension <tt/.f/, then do:
-
-<tscreen><verb>
-$ g77 myprog.f
-</verb></tscreen>
-
-which creates by default an executable called <tt/a.out/ (you don't have
-to link anything). To give the executable a different name and do some
-optimisation:
-
-<tscreen><verb>
-$ g77 -O2 -o myprog myprog.f
-</verb></tscreen>
-
-Beware of optimisations! Ask your sysadm to read the documentation that
-comes with the compiler and tell you if there are any problems.
-
-To compile a subroutine:
-
-<tscreen><verb>
-$ g77 -c mysub.f
-</verb></tscreen>
-
-This creates a file <tt/mysub.o/. To link this subroutine to a program,
-you'll do
-
-<tscreen><verb>
-$ g77 -o myprog myprog.f mysub.o
-</verb></tscreen>
-
-If you have many external subroutines and you want to make a library, do the
-following:
-
-<tscreen><verb>
-$ cd subroutines/
-$ cat *f >mylib.f ; g77 -c mylib.f
-</verb></tscreen>
-
-This will create <tt/mylib.o/ that you can link to your programs.
-
-Finally, to link an external library called, say, <tt/libdummy.so/:
-
-<tscreen><verb>
-$ g77 -o myprog myprog.f -ldummy
-</verb></tscreen>
-
-If you have <tt/f2c/, you only have to use <tt/f77/ or <tt/fort77/ instead
-of <tt/g77/.
-
-Another useful programming tool is <tt/make/, described below.
-
-
-<sect1> Using <tt/make/
-
-<p>
-
-The utility <tt/make/ is a tool to handle the compilation of programs that
-are split into several source files. The VMS counterparts are <tt>MMS</tt>
-and <tt>MMK</tt>, which have a different syntax.
-
-Let's suppose you have source files containing your routines, <tt/file_1.f,
-file_2.f, file_3.f/, and a source file of the main program that uses the
-routines, <tt/myprog.f/. If you compile your program manually, whenever you
-modify one of the source files you have to figure out which file depends on
-which, which file to recompile first, and so on.
-
-Instead of getting mad, you can write a `makefile'. This is a text file
-containing the dependencies between your sources: when one is modified, only
-the ones that depend on the modified file will be recompiled.
-
-In our example, you'd write a makefile like this:
-
-<code>
-
-# This is makefile
-# Press the <TAB> key where you see <TAB>!
-# It's important: don't use spaces instead.
-
-myprog: myprog.o file_1.o file_2.o file_3.o
-<TAB>g77 -o myprog myprog.o file_1.o file_2.o file_3.o
-# myprog depends on four object files
-
-myprog.o: myprog.f
-<TAB>g77 -c myprog.f
-# myprog.o depends on its source file
-
-file_1.o: file_1.f
-<TAB>g77 -c file_1.f
-# file_1.o depends on its source file
-
-file_2.o: file_2.f file_1.o
-<TAB>g77 -c file_2.f file_1.o
-# file_2.o depends on its source file and an object file
-
-file_3.o: file_3.f file_2.o
-<TAB>g77 -c file_3.f file_2.o
-# file_3.o depends on its source file and an object file
-
-# end of makefile.
-</code>
-
-Save this file as <tt/Makefile/ and type <tt/make/ to compile your program;
-alternatively, save it as <tt/myprog.mak/ and type <tt/make -f myprog.mak/.
-And of course, RMP.
-
-
-<sect1> Shell Scripts
-
-<p>
-
-Shell scripts are the equivalent of VMS' command files, and allow for very
-powerful constructs.
-
-To write a script, all you have to do is write a standard ASCII file
-containing the commands, save it, then make it executable with the
-command <tt/chmod +x <scriptfile>/. To execute it, type its name.
-
-Writing scripts under <tt/bash/ is such a vast subject it would require a
-book by itself, and I will not delve into the topic any further. I'll just
-give you a more-or-less comprehensive and (hopefully) useful example you can
-extract some basic rules from.
-
-EXAMPLE: sample.sh
-
-<code>
-#!/bin/sh
-# sample.sh
-# I am a comment
-# don't change the first line, it must be there
-echo "This system is: `uname -a`" # use the output of the command
-echo "My name is $0" # built-in variables
-echo "You gave me the following $# parameters: "$*
-echo "First parameter is: "$1
-echo -n "What's your name? " ; read your_name
-echo notice the difference: "hi $your_name" # quoting with "
-echo notice the difference: 'hi $your_name' # quoting with '
-DIRS=0 ; FILES=0
-for file in `ls .` ; do
- if [ -d ${file} ] ; then # if file is a directory
- DIRS=`expr $DIRS + 1` # this means DIRS = DIRS + 1
- elif [ -f ${file} ] ; then
- FILES=`expr $FILES + 1`
- fi
- case ${file} in
- *.gif|*jpg) echo "${file}: graphic file" ;;
- *.txt|*.tex) echo "${file}: text file" ;;
- *.c|*.f|*.for) echo "${file}: source file" ;;
- *) echo "${file}: generic file" ;;
- esac
-done
-echo "there are ${DIRS} directories and ${FILES} files"
-ls | grep "ZxY--!!!WKW"
-if [ $? != 0 ] ; then # exit code of last command
- echo "ZxY--!!!WKW not found"
-fi
-echo "enough... type 'man bash' if you want more info."
-
-</code>
-
-<sect1> C <label id="C">
-
-<p>
-
-Linux is an excellent environment to program in C. Taken for granted that
-you know C, here are a couple of guidelines. To compile your standard
-<tt/hello.c/ you'll use the <tt/gcc/ compiler, which comes as part of Linux
-and has the same syntax as <tt/g77/:
-
-<tscreen><verb>
-$ gcc -O2 -o hello hello.c
-</verb></tscreen>
-
-To link a library to a program, add the switch <tt>-l<libname></tt>.
-For example, to link the math library and optimize do
-
-<tscreen><verb>
-$ gcc -O2 -o mathprog mathprog.c -lm
-</verb></tscreen>
-
-(The <tt>-l<libname></tt> switch forces <tt/gcc/ to link the library
-<tt>/usr/lib/lib<libname>.a</tt>; so <tt/-lm/ links
-<tt>/usr/lib/libm.a</tt>).
-
-When your program is made of several source files, you'll need to use the
-utility <tt/make/ described above. Just use <tt/gcc/ and C source files in
-the makefile.
-
-You can invoke some help about the C functions, that are covered by man
-pages, section 3; for example,
-
-<tscreen><verb>
-$ man 3 printf
-</verb></tscreen>
-
-There are lots of libraries available out there; among the first you'll want
-to use are <tt/ncurses/, to handle text mode effects, and <tt/svgalib/, to
-do graphics.
-
-
-<sect> Graphics <label id="Graphics">
-
-<p>
-
-Among the scores of graphic packages available, <tt/gnuplot/ stands out
-for its power and ease of use. Go to X and type <tt/gnuplot/, and have
-two sample data files ready: <tt/2D-data.dat/ (two data per line), and
-<tt/3D-data.dat/ (three data per line).
-
-Examples of 2-D graphs:
-
-<tscreen><verb>
-gnuplot> set title "my first graph"
-gnuplot> plot '2D-data.dat'
-gnuplot> plot '2D-data.dat' with linespoints
-gnuplot> plot '2D-data.dat', sin(x)
-gnuplot> plot [-5:10] '2D-data.dat'
-</verb></tscreen>
-
-Example of 3-D graphs (each `row' of X values is followed by a blank
-line):
-
-<tscreen><verb>
-gnuplot> set parametric ; set hidden3d ; set contour
-gnuplot> splot '3D-data.dat' using 1:2:3 with linespoints
-</verb></tscreen>
-
-A single-column datafile (e.g., a time series) can also be plotted as a 2-D
-graph:
-
-<tscreen><verb>
-gnuplot> plot [-5:15] '2D-data-1col.dat' with linespoints
-</verb></tscreen>
-
-or as a 3-D graph (blank lines in the datafile, as above):
-
-<tscreen><verb>
-gnuplot> set noparametric ; set hidden3d
-gnuplot> splot '3D-data-1col.dat' using 1 with linespoints
-</verb></tscreen>
-
-To print a graph: if the command to print on your Postscript printer is
-<tt/lpr -Pps file.ps/, issue:
-
-<tscreen><verb>
-gnuplot> set term post
-gnuplot> set out '| lpr -Pps'
-gnuplot> replot
-</verb></tscreen>
-
-then type <tt/set term x11/ to restore. Don't get confused---the last print
-will come out only when you quit <tt/gnuplot/.
-
-For more info, type <tt/help/ or see the examples in directory
-<tt>/usr/lib/gnuplot/demos/</tt>, if you have it.
-
-
-<sect> Mail and Internet Tools <label id="Mail and Internet Tools">
-
-<p>
-
-Since Internet was born on UNIX machines, you find plenty of nice and
-easy-to-use applications under Linux. Here are just some:
-
-<itemize>
-
-<item> <bf/Mail/: use <tt/elm/ or <tt/pine/ to handle your email; both
-programs have on-line help. For short messages, you could use <tt/mail/, as
-in <tt/mail -s "hello mate" user@somewhere < msg.txt/. You may like programs
-like <tt/xmail/ or some such.
-
-<item> <bf/Newsgroups/: use <tt/tin/ or <tt/slrn/, both very intuitive and
-self-explanatory.
-
-<item> <bf/ftp/: apart from the usual character-based <tt/ftp/, ask your
-sysadm to install the full-screen <tt/ncftp/ or a graphical ftp client like
-<tt/xftp/.
-
-<item> <bf/WWW/: the ubiquitous <tt/netscape/, or <tt/xmosaic/,
-<tt/chimera/, and <tt/arena/ are graphical web browsers; a character-based
-one is <tt/lynx/, quick and effective.
-
-</itemize>
-
-<sect> Advanced Topics <label id="Advanced Topics">
-
-<p>
-
-Here the game gets tough. Learn these features, then you'll be ready to say
-that you `know something about Linux' ;-)
-
-
-<sect1> Permissions and Ownership <label id="Permissions">
-
-<p>
-
-Files and directories have permissions (`protections') and ownership, just
-like under VMS. If you can't run a program, or can't modify a file, or can't
-access a directory, it's because you don't have the permission to do so,
-and/or because the file doesn't belong to you. Let's have a look at the
-following example:
-
-<tscreen><verb>
-$ ls -l /bin/ls
--rwxr-xr-x 1 root bin 27281 Aug 15 1995 /bin/ls*
-</verb></tscreen>
-
-The first field shows the permissions of the file <tt/ls/ (owner root,
-group bin). There are three types of ownership: owner, group, and others
-(similar to VMS owner, group, world), and three types of permissions:
-read, write (and delete), and execute.
-
-From left to right, <tt/-/ is the file type (<tt/-/ = ordinary file, <tt/d/
-= directory, <tt/l/ = link, etc); <tt/rwx/ are the permissions for the file
-owner (read, write, execute); <tt/r-x/ are the permissions for the group of
-the file owner (read, execute); <tt/r-x/ are the permissions for all other
-users (read, execute).
-
-To change a file's permissions:
-
-<tscreen><verb>
-$ chmod <whoXperm> <file>
-</verb></tscreen>
-
-where who is <tt/u/ (user, that is owner), <tt/g/ (group), <tt/o/ (other),
-X is either <tt/+/ or <tt/-/, perm is <tt/r/ (read), <tt/w/ (write), or
-<tt/x/ (execute). Examples:
-
-<tscreen><verb>
-$ chmod u+x file
-</verb></tscreen>
-
-this sets the execute permission for the file owner. Shortcut:
-<tt/chmod +x file/.
-
-<tscreen><verb>
-$ chmod go-wx file
-</verb></tscreen>
-
-this removes write and execute permission for everyone except the owner.
-
-<tscreen><verb>
-$ chmod ugo+rwx file
-</verb></tscreen>
-
-this gives everyone read, write, and execute permission.
-
-A shorter way to refer to permissions is with numbers: <tt/rwxr-xr-x/ can be
-expressed as 755 (every letter corresponds to a bit: <tt/---/ is 0,
-<tt/--x/ is 1, <tt/-w-/ is 2...).
-
-For a directory, <tt/rx/ means that you can <tt/cd/ to that directory, and
-<tt/w/ means that you can delete a file in the directory (according to the
-file's permissions, of course), or the directory itself. All this is only
-part of the matter---RMP.
-
-To change a file's owner:
-
-<tscreen><verb>
-$ chown username file
-</verb></tscreen>
-
-To sum up, a table:
-
-<tscreen><verb>
-VMS Linux Notes
-------------------------------------------------------------------------------
-
-SET PROT=(O:RW) file.txt $ chmod u+rw file.txt
- $ chmod 600 file.txt
-SET PROT=(O:RWED,W) file $ chmod u+rwx file
- $ chmod 700 file
-SET PROT=(O:RWED,W:RE) file $ chmod 755 file
-SET PROT=(O:RW,G:RW,W) file $ chmod 660 file
-SET FILE/OWNER_UIC=JOE file $ chown joe file
-SET DIR/OWNER_UIC=JOE [.dir] $ chown joe dir/
-</verb></tscreen>
-
-
-<sect1> Multitasking: Processes and Jobs <label id="Multitasking">
-
-<p>
-
-More about running programs. There are no `batch queues' under Linux as
-you're used to; multitasking is handled very differently. Again, this is
-what the typical command line looks like:
-
-<tscreen><verb>
-$ command -s1 -s2 ... -sn par1 par2 ... parn < input > output &
-</verb></tscreen>
-
-where <tt>-s1</tt>, ..., <tt>-sn</tt> are the program switches,
-<tt/par1/, ..., <tt/parn/ are the program parameters.
-
-Now let's see how multitasking works. Programs, running in foreground or
-background, are called `processes'.
-
-<itemize>
-
-<item> To launch a process in background:
-<tscreen><verb>
-$ progname [-switches] [parameters] [< input] [> output] &
-[1] 234
-</verb></tscreen>
-the shell tells you what the `job number' (the first digit; see below) and
-PID (Process IDentifier) of the process are. Each process is identified
-by its PID.
-
-<item> To see how many processes there are:
-<tscreen><verb>
-$ ps -ax
-</verb></tscreen>
-This will output a list of currently running processes.
-
-<item> To kill a process:
-<tscreen><verb>
-$ kill <PID>
-</verb></tscreen>
-You may need to kill a process when you don't know how to quit it
-the right way... ;-). Sometimes, a process will only be killed by
-one of the following:
-<tscreen><verb>
-$ kill -15 <PID>
-$ kill -9 <PID>
-</verb></tscreen>
-
-</itemize>
-
-In addition to this, the shell allows you to stop or temporarily suspend a
-process, send a process to background, and bring a process from background
-to foreground. In this context, processes are called `jobs'.
-
-<itemize>
-
-<item> To see how many jobs there are:
-<tscreen><verb>
-$ jobs
-</verb></tscreen>
-jobs are identified by the numbers the shell gives them, not by their PID.
-
-<item> To stop a process running in foreground:
-<tscreen><verb>
-$ CTRL-C
-</verb></tscreen>
-(it doesn't always work)
-
-<item> To suspend a process running in foreground:
-<tscreen><verb>
-$ CTRL-Z
-</verb></tscreen>
-(ditto)
-
-<item> To send a suspended process into background (it becomes a job):
-<tscreen><verb>
-$ bg <job>
-</verb></tscreen>
-
-<item> To bring a job to foreground:
-<tscreen><verb>
-$ fg <job>
-</verb></tscreen>
-
-<item> To kill a job:
-<tscreen><verb>
-$ kill <%job>
-</verb></tscreen>
-
-</itemize>
-
-<sect1> Files, Revisited
-
-<p>
-
-More information about files.
-
-<itemize>
-
-<item> <bf/stdin, stdout, stderr/: under UNIX, every system component is
-treated as if it were a file. Commands and programs get their input from a
-`file' called <tt/stdin/ (standard input; usually, the keyboard), put their
-output on a `file' called <tt/stdout/ (usually, the screen), and error
-messages go to a `file' called <tt/stderr/ (usually, the screen).
-
-Using <tt/</ and <tt/>/ you redirect input and output to a different
-file. Moreover, <tt/>>/ appends the output to a file instead of
-overwriting it; <tt/2>/ redirects error messages (stderr); 2>&1
-redirects stderr to stdout, while 1>&2 redirects stdout to stderr.
-There's a `black hole' called <tt>/dev/null</tt>: everything redirected to
-it disappears;
-
-<item> <bf/wildcards/: '<tt/*/' is almost the same. Usage: * matches all
-files except the hidden ones; .* matches all hidden files; *.* matches
-only those that have a '.' in the middle, followed by other characters;
-p*r matches both `peter' and `piper'; *c* matches both `picked' and `peck'.
-'<tt/%/' becomes '<tt/?/'. There is another wildcard: the
-<tt/[]/. Usage: <tt/[abc]*/ matches files starting with a, b, c;
-<tt/*[I-N,1,2,3]/ matches files ending with I, J, K, L, M, N, 1, 2, 3;
-
-<item> <tt/mv/ (<tt/RENAME/) doesn't work for multiple files; that is,
-<tt/mv *.xxx *.yyy/ won't work;
-
-<item> use <tt/cp -i/ and <tt/mv -i/ to be warned when a file is going to
-be overwritten.
-
-</itemize>
-
-
-<sect1> Print Queues <label id="Print Queues">
-
-<p>
-
-Your prints are queued, like under VMS. When you issue a print command, you
-may specify a printer name. Example:
-
-<tscreen><verb>
-$ lpr file.txt # this goes to the standard printer
-$ lpr -Plaser file.ps # this goes to the printer named 'laser'
-</verb></tscreen>
-
-To handle the print queues, you use the following commands:
-
-<tscreen><verb>
-
-VMS Linux
-------------------------------------------------------------------------------
-
-$ PRINT file.ps $ lpr file.ps
-$ PRINT/QUEUE=laser file.ps $ lpr -Plaser file.ps
-$ SHOW QUEUE $ lpq
-$ SHOW QUEUE/QUEUE=laser $ lpq -Plaser
-$ STOP/QUEUE $ lprm <item>
-
-</verb></tscreen>
-
-
-<sect> Configuring <label id="Configuring">
-
-<p>
-
-Your sysadm has already provided you with a number of configuration files
-like <tt/.xinitrc/, <tt/.bash_profile/, <tt/.inputrc/, and many others. The
-ones you may want to edit are:
-
-<itemize>
-
-<item> <tt/ .bash_profile/ or <tt/.profile/: read by the shell at login
-time. It's like <tt/LOGIN.COM/;
-
-<item> <tt/ .bash_logout/: read by the shell at logout. It's like
-<tt/LOGOUT.COM/;
-
-<item> <tt/ .bashrc/: read by non--login shells.
-
-<item> <tt/ .inputrc/: this file customises the key bindings and the
-behaviour of the shell.
-
-</itemize>
-
-To give you an example, I'll include my <tt/.bash_profile/ (abridged):
-
-<code>
-# $HOME/.bash_profile
-
-# don't redefine the path if not necessary
-echo $PATH | grep $LOGNAME > /dev/null
-if [ $? != 0 ]
-then
- export PATH="$PATH:/home/$LOGNAME/bin" # add my dir to the PATH
-fi
-
-export PS1='LOGNAME:\w\$ '
-export PS2='Continued...>'
-
-# aliases
-
-alias bin="cd ~/bin" ; alias cp="cp -i" ; alias d="dir"
-alias del="delete" ; alias dir="/bin/ls $LS_OPTIONS --format=vertical"
-alias ed="jed" ; alias mv='mv -i'
-alias u="cd .." ; alias undel="undelete"
-
-# A few useful functions
-
-inst() # Install a .tar.gz archive in current directory.
-{
- gzip -dc $1 | tar xvf -
-}
-cz() # List the contents of a .zip archive.
-{
- unzip -l $*
-}
-ctgz() # List the contents of a .tar.gz archive.
-{
- for file in $* ; do
- gzip -dc ${file} | tar tf -
- done
-}
-tgz() # Create a .tgz archive a la zip.
-{
- name=$1 ; tar -cvf $1 ; shift
- tar -rf ${name} $* ; gzip -S .tgz ${name}
-}
-</code>
-
-And this is my <tt/.inputrc/:
-
-<code>
-# $HOME/.inputrc
-# Last modified: 16 January 1997.
-#
-# This file is read by bash and defines key bindings to be used by the shell;
-# what follows fixes the keys END, HOME, and DELETE, plus accented letters.
-# For more information, man readline.
-
-"\e[1~": beginning-of-line
-"\e[3~": delete-char
-"\e[4~": end-of-line
-
-set bell-style visible
-set meta-flag On
-set convert-meta Off
-set output-meta On
-set horizontal-scroll-mode On
-set show-all-if-ambiguous On
-
-# (F1 .. F5) are "\e[[A" ... "\e[[E"
-
-"\e[[A": "info "
-</code>
-
-
-<sect> Useful Programs <label id="Useful Programs">
-
-<p>
-
-<sect1> Browsing Files: <tt/less/
-
-<p>
-
-You'll use this file browser every day, so I'll give you a couple of tips to
-use it at best. First of all, ask your sysadm to configure <tt/less/ so as
-it can display not only plain text files, but also compressed files,
-archives, and so on.
-
-Like recent versions of <tt>TYPE</tt>, <tt/less/ lets you browse files
-in both directions. It also accepts several commands that are issued
-pressing a key. The most useful are:
-
-<itemize>
-
-<item> first of all, press <tt/q/ to leave the browser;
-
-<item> <tt/h/ gives you extensive help;
-
-<item> <tt/g/ to go to beginning of file, <tt/G/ to the end, number+<tt/g/
-to go to line `number' (e.g. <tt/125g/), number+<tt/%/ to move to that
-percentage of the file;
-
-<item> <tt>/pattern</tt> searches forwards for `pattern'; <tt/n/ searches
-forwards for the next match; <tt>?pattern</tt> and <tt/N/ search backwards;
-
-<item> <tt/m/+letter marks current position (e.g. <tt/ma/); <tt/'/+letter go
-to the marked position.
-
-<item> <tt/:e/ examines a new file;
-
-<item> <tt/!command/ executes the shell command.
-
-</itemize>
-
-
-<sect1> Numbered Backups Under Linux <label id="Numbered Backups Under Linux">
-
-<p>
-
-Alas, Linux doesn't still support file version numbers, but you overcome
-this limitation in two ways. The first is to use RCS, the Revision Control
-System, which allows you to keep previous versions of a file. RCS is
-covered in ``The RCS MINI-HOWTO'' (<url
-url="http://sunsite.unc.edu/mdw/HOWTO/mini/RCS.html">).
-
-The second way is to use an editor that knows how to deal with numbered
-backups; <tt>emacs</tt> and <tt>jed</tt> are OK. In <tt>emacs</tt>, add
-these lines in your <tt>.emacs</tt>:
-
-<tscreen><verb>
-(setq version-control t)
-(setq kept-new-versions 15) ;;; or any other value
-(setq kept-old-versions 15)
-(setq backup-by-copying-when-linked t)
-(setq backup-by-copying-when-mismatch t)
-</verb></tscreen>
-
-In <tt>jed</tt>, make sure you have version 0.98.7 or newer; the patch for
-numbered backups is available on <tt> <url
-url="http://ibogeo.df.unibo.it/guido/slang/backups.sl"> </tt>.
-
-
-<sect1> Archiving: tar & gzip
-
-<p>
-
-Under UNIX there are some widely used applications to archive and
-compress files. <tt/tar/ is used to make archives, that is collections of
-files. To make a new archive:
-
-<tscreen><verb>
-$ tar -cvf <archive_name.tar> <file> [file...]
-</verb></tscreen>
-
-To extract files from an archive:
-
-<tscreen><verb>
-$ tar -xpvf <archive_name.tar> [file...]
-</verb></tscreen>
-
-To list the contents of an archive:
-
-<tscreen><verb>
-$ tar -tf <archive_name.tar> | less
-</verb></tscreen>
-
-Files can be compressed to save disk space using <tt/compress/, which is
-obsolete and shouldn't be used any more, or <tt/gzip/:
-
-<tscreen><verb>
-$ compress <file>
-$ gzip <file>
-</verb></tscreen>
-
-that creates a compressed file with extension .Z (<tt/compress/) or .gz
-(<tt/gzip/). These programs don't make archives, but compress files
-individually. To decompress, use:
-
-<tscreen><verb>
-$ compress -d <file.Z>
-$ gzip -d <file.gz>
-</verb></tscreen>
-
-RMP.
-
-The <tt/unarj/, <tt/zip/ and <tt/unzip/ utilities are also available. Files
-with extension <tt/.tar.gz/ or <tt/.tgz/ (archived with <tt/tar/, then
-compressed with <tt/gzip/) are very common in the UNIX world. Here's how to
-list the contents of a <tt/.tar.gz/ archive:
-
-<tscreen><verb>
-$ tar -ztf <file.tar.gz> | less
-</verb></tscreen>
-
-To extract the files from a <tt/.tar.gz/ archive:
-
-<tscreen><verb>
-$ tar -zxf <file.tar.gz>
-</verb></tscreen>
-
-
-<sect> Real Life Examples <label id="Examples">
-
-<p>
-
-UNIX' core idea is that there are many simple commands that can linked
-together via piping and redirection to accomplish even really complex tasks.
-Have a look at the following examples. I'll only explain the most complex
-ones; for the others, please study the above sections and the man pages.
-
-<bf/Problem/: <tt/ls/ is too quick and the file names fly away.
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ ls | less
-</verb></tscreen>
-
-<bf/Problem/: I have a file containing a list of words. I want to sort it
-in reverse order and print it.
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ cat myfile.txt | sort -r | lpr
-</verb></tscreen>
-
-<bf/Problem/: my data file has some repeated lines! How do I get rid of them?
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ sort datafile.dat | uniq > newfile.dat
-</verb></tscreen>
-
-<bf/Problem/: I have a file called 'mypaper.txt' or 'mypaper.tex' or some
-such somewhere, but I don't remember where I put it. How do I find it?
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ find ~ -name "mypaper*"
-</verb></tscreen>
-
-Explanation: <tt/find/ is a very useful command that lists all the files
-in a directory tree (starting from <tt/˜/ in this case). Its output
-can be filtered to meet several criteria, such as <tt/-name/.
-
-<bf/Problem/: I have a text file containing the word 'entropy' in this
-directory, is there anything like <tt/SEARCH/?
-
-<bf/Solution/: yes, try
-
-<tscreen><verb>
-$ grep -l 'entropy' *
-</verb></tscreen>
-
-<bf/Problem/: somewhere I have text files containing the word 'entropy', I'd
-like to know which and where they are. Under VMS I'd use <tt/search entropy
-[...]*.*;*/, but <tt/grep/ can't recurse subdirectories. Now what?
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ find . -exec grep -l "entropy" {} \; 2> /dev/null
-</verb></tscreen>
-
-Explanation: <tt/find ./ outputs all the file names starting from the
-current directory, <tt/-exec grep -l "entropy"/ is an action to be
-performed on each file (represented by <tt/{}/), <tt/\/
-terminates the command. If you think this syntax is awful, you're right.
-
-In alternative, write the following script:
-
-<code>
-#!/bin/sh
-# rgrep: recursive grep
-if [ $# != 3 ]
-then
- echo "Usage: rgrep --switches 'pattern' 'directory'"
- exit 1
-fi
-find $3 -name "*" -exec grep $1 $2 {} \; 2> /dev/null
-</code>
-
-Explanation: <tt/grep/ works like <tt/search/, and combining it with
-<tt/find/ we get the best of both worlds.
-
-<bf/Problem/: I have a data file that has two header lines, then every
-line has 'n' data, not necessarily equally spaced. I want the 2nd and
-5th data value of each line. Shall I write a Fortran program...?
-
-<bf/Solution/: nope. This is quicker:
-
-<tscreen><verb>
-$ awk 'NL > 2 {print $2, "\t", $5}' datafile.dat > newfile.dat
-</verb></tscreen>
-
-Explanation: the command <tt/awk/ is actually a programming language:
-for each line starting from the third in <tt/datafile.dat/, print out
-the second and fifth field, separated by a tab. Learn some <tt/awk/---it
-saves a lot of time.
-
-<bf/Problem/: I've downloaded an FTP site's <tt/ls-lR.gz/ to check its
-contents. For each subdirectory, it contains a line that reads "total xxxx",
-where xxxx is size in kbytes of the dir contents. I'd like to get the grand
-total of all these xxxx values.
-
-<bf/Solution/:
-
-<tscreen><verb>
-$ zcat ls-lR.gz | awk ' $1 == "total" { i += $2 } END {print i}'
-</verb></tscreen>
-
-Explanation: <tt/zcat/ outputs the contents of the <tt/.gz/ file and pipes
-to <tt/awk/, whose man page you're kindly requested to read ;-)
-
-<bf/Problem/: I've written a Fortran program, <tt/myprog/, to calculate a
-parameter from a data file. I'd like to run it on hundreds of data files
-and have a list of the results, but it's a nuisance to ask each time for
-the file name. Under VMS I'd write a lengthy command file, and under Linux?
-
-<bf/Solution/: a very short script. Make your program look for the data
-file '<tt/mydata.dat/' and print the result on the screen (stdout), then
-write the following script:
-
-<code>
-#!/bin/sh
-# myprog.sh: run the same command on many different files
-# usage: myprog.sh *.dat
-for file in $* # for all parameters (e.g. *.dat)
-do
- # append the file name to result.dat
- echo -n "${file}: " >> results.dat
- # copy current argument to mydata.dat, run myprog
- # and append the output to results.dat
- cp ${file} mydata.dat ; myprog >> results.dat
-done
-</code>
-
-<bf/Problem/: I want to replace `geology' with `geophysics' in all my
-text files. Shall I edit them all manually?
-
-<bf/Solution/: nope. Write this shell script:
-
-<code>
-#!/bin/sh
-# replace $1 with $2 in $*
-# usage: replace "old-pattern" "new-pattern" file [file...]
-OLD=$1 # first parameter of the script
-NEW=$2 # second parameter
-shift ; shift # discard the first 2 parameters: the next are the file names
-for file in $* # for all files given as parameters
-do
-# replace every occurrence of OLD with NEW, save on a temporary file
- sed "s/$OLD/$NEW/g" ${file} > ${file}.new
-# rename the temporary file as the original file
- /bin/mv ${file}.new ${file}
-done
-</code>
-
-<bf/Problem/: I have some data files, I don't know their length and have to
-remove their last but one and last but two lines. Er... manually?
-
-<bf/Solution/: no, of course. Write this script:
-
-<code>
-#!/bin/sh
-# prune.sh: removes n-1th and n-2th lines from files
-# usage: prune.sh file [file...]
-for file in $* # for every parameter
-do
- LINES=`wc -l $file | awk '{print $1}'` # number of lines in file
- LINES=`expr $LINES - 3` # LINES = LINES - 3
- head -n $LINES $file > $file.new # output first LINES lines
- tail -n 1 $file >> $file.new # append last line
-done
-</code>
-
-I hope these examples whetted your appetite...
-
-
-<sect> Tips You Can't Do Without
-
-<p>
-
-<itemize>
-
-<item> <bf/Command completion/: pressing <TAB> when issuing a command
-will complete the command line for you. Example: you have to type
-<tt>less this_is_a_long_name</tt>; typing in <tt>less thi<TAB></tt>
-will suffice. (If you have other files that start with the same
-characters, supply enough characters to resolve any ambiguity.)
-
-<item> <bf/Back-scrolling/: pressing SHIFT--PAG UP (the grey key) allows
-you to backscroll a few pages, depending on your PC's video memory.
-
-<item> <bf/Resetting the screen/: if you happen to <tt/more/ or <tt/cat/
-a binary file, your screen may end up full of garbage. To fix things,
-blind type <tt/reset/ or this sequence of characters:
-<tt/echo CTRL-V ESC c RETURN/.
-
-<item> <bf/Pasting text/: in console, see below; in X, click and drag to
-select the text in an <tt/xterm/ window, then click the middle button
-(or the two buttons together if you have a two-button mouse) to paste.
-
-<item> <bf/Using the mouse/: ask your sysadm to install <tt/gpm/, a mouse
-driver for the console. Click and drag to select text, then right click
-to paste the selected text. It works across different VCs.
-
-</itemize>
-
-
-<sect> Reading VMS tapes from Linux
-
-<p>
-
-(This section was written by Mike Miller)
-
-<sect1> Introduction
-
-<p>
-
-From time to time you may want to read tapes made on a VMS machine (or tapes
-that are made to be readable by VMS and *nix systems). In general, this is
-quite easy for DECFILES11A tapes.
-
-Although you may be reading this as part of a Linux mini-HOWTO, I believe
-that the information here is applicable to any *nix system - I've done this
-on Linux, HP, Sun and DEC *nix systems. The main platform dependences that I
-know are device names, which can differ on different systems, and the
-options to mt for specifying the device name (for example, mt -f on Linux
-and mt -t on HPUX 9).
-
-Caveat - I've only tried this with Exabyte 8mm SCSI tape drives. If you've
-read other formats (still got those 9-tracks lying around?) let me know and
-I'll add a note here.
-
-
-<sect1> The Basics
-
-<p>
-
-When reading a tape that has been made with the VMS ``copy'' command (or has
-at least been made to look like it was made with copy) all you need to know
-is there will be three files on the tape for each actual data file - a
-header, the data, and a trailer. The header and trailer are interesting in
-that they contain info on the file as it existed under VMS. The data is,
-well, the data. Each of these files can be extracted from the tape with the
-dd command. The tape can be positioned by skipping around with the mt
-command.
-
-Example: I've got VMS tape with a series of files on it. The first two were
-originally named ce66-2.evt and ce66-3.evt on a VMS system. The tape label
-is c66a2.
-
-If I execute these commands:
-
-<tscreen><verb>
-> dd if=$TAPE bs=16k of=header1
-> dd if=$TAPE bs=16k of=data1
-> dd if=$TAPE bs=16k of=trailer1
-> dd if=$TAPE bs=16k of=header2
-> dd if=$TAPE bs=16k of=data2
-> dd if=$TAPE bs=16k of=trailer2
-</verb></tscreen>
-
-I'm left with six files: header1, data1, trailer1, header2, data2 and
-trailer2. The syntax here is if="input file", bs="block size" and
-of="output file". TAPE is expected to be a variable containing the device
-name of your tape drive - for example, /dev/nts0 if you are using the first
-SCSI tape on Linux.
-
-If you wanted to read the second file, but not the first, you didn't care
-about the header, and you wanted to use the original file name, do this:
-
-<tscreen><verb>
-> mt -f $TAPE fsf 4
-> dd if=$TAPE bs=16k of=ce66-2.evt
-> mt -f $TAPE fsf 1
-</verb></tscreen>
-
-Note the 4 - skip three files for the first file on the tape and one for the
-next header. The second mt skips the second file's trailer and positions
-the tape at the beginning of the next file - the third VMS header. You can
-also use mt to skip backwards (bsf), rewind (rewind) and rewind and unload
-the tape (offline, rewoffl).
-
-
-<sect1> Some details
-
-<p>
-
-
-The header and trailer files contain uppercase ASCII data used by VMS to
-store file information such as block size. They also contain the file name,
-which can be handy if you want to build scripts that automate read files or
-search for a particular file. The first header on a tape volume is slightly
-different than subsequent headers.
-
-For a file that is the first file on the tape, as in header1 of the above
-example, the first four characters will be "VOL1" followed by the volume
-name. In the example, header1 starts with "VOL1C66A2". This is followed by
-a series of spaces terminated with a numeral. After that is the string
-"HDR1" which indicates that this is a file header. The characters
-immediately following the HDR1 string are the VMS file name. In in the
-example, this is "HDR1CE66-2.EVT". The next field is the volume name again.
-
-For files that are not the first file on the tape, the initial VOL1 field is
-not present. Other than that the header has the same structure as for the
-initial file. Another useful field is the 7th field, which will end with
-"DECFILES11A". This must be present on tapes that conform to the DEC
-Files11A standard.
-
-<tscreen><verb>
- field initial header subsequent headers
- ===== ============= ==================
- 1 VOL1 + volume name HDR1 + file name
- 2 3HDR1 + file name volume name
- 3 volume name
-
- 6 ...DECFILES11A
- 7 ...DECFILES11A
-</verb></tscreen>
-
-For full details on the header and trailer format, see the DEC FILES11A
-documentation (on the orange/grey wall - ask your local VMS folks :-).
-
-
-<sect1> Comment on Block Size
-
-<p>
-
-In the example, I used a block size of 16k. On a *nix system, there is no
-block size associated with a file on disk while, under VMS, each file has a
-specific block size. That means that block size doesn't matter too much on
-the Linux end... unless it makes it hard to read the tape. If you have
-difficulty figuring out the block size and reading a tape, you can try
-setting the hardware block size on your tape drive using `mt -f $TAPE setblk
-0'. The exact form of the setblk option (and its availability) may depend
-on the version of mt, the tape drive hardware interface and on your
-particular flavor of *nix.
-
-(Thanks to Wojtek Skulski (<url
-url="skulski@nsrlc6.nsrl.rochester.edu">)
-for pointing out setblk.)
-
-
-<sect> The End
-
-<p>
-
-<sect1> Copyright
-
-<p>
-
-Unless otherwise stated, Linux HOWTO documents are copyrighted by their
-respective authors. Linux HOWTO documents may be reproduced and distributed
-in whole or in part, in any medium physical or electronic, as long as this
-copyright notice is retained on all copies. Commercial redistribution is
-allowed and encouraged; however, the author would like to be notified of any
-such distributions.
-
-All translations, derivative works, or aggregate works incorporating any
-Linux HOWTO documents must be covered under this copyright notice. That is,
-you may not produce a derivative work from a HOWTO and impose additional
-restrictions on its distribution. Exceptions to these rules may be granted
-under certain conditions; please contact the Linux HOWTO coordinator at the
-address given below.
-
-In short, we wish to promote dissemination of this information through as
-many channels as possible. However, we do wish to retain copyright on the
-HOWTO documents, and would like to be notified of any plans to redistribute
-the HOWTOs.
-
-If you have questions, please contact Tim Bynum, the Linux HOWTO
-coordinator, at <url url="linux-howto@sunsite.unc.edu"> via email.
-
-
-<sect1> Disclaimer
-
-<p>
-
-This work was written following the experience we had at the Settore di
-Geofisica of the Universita' di Bologna (Italy), where a VAX 4000 has been
-superseded and replaced by Linux-based Pentium PCs. Most of my colleagues
-are VMS users, and some of them have switched to Linux.
-
-``From VMS to Linux HOWTO'' was written by Guido Gonzato, <url
-url="guido ``at'' ibogeo.df.unibo.it">, and Mike Miller,
-<url url="miller5@uiuc.edu"> who contributed the section on reading VMS tapes.
-Many thanks to my colleagues and friends who helped me define the needs and
-habits of the average VMS user, especially to Dr. Warner Marzocchi.
-
-Please help me improve this HOWTO. I'm not a VMS expert and never will be,
-so your suggestions and bug reports are more than welcome.
-
-Enjoy,
-
-Guido <tt/=8-)/
-
-</article>