Global change to many pages...

Various pages use inconsistent terms for 'null byte' (which
is the C99/SUSv3 term for the '\0' character).
To rectify this the following changes were made in these pages:

Replace 'zero byte' with 'null byte'.
Replace 'null character' with 'null byte'.
Replace 'nulls' with 'null bytes'.
Replace 'NUL-terminated' by 'null-terminated'.
Replace 'NUL' by 'null byte'.
Replace 'terminating NUL' by 'terminating null byte'.
Replace 'final NUL' by 'terminating null byte'.
Replace 'NUL character' by 'null byte'.

Changes

@@ -16,6 +16,21 @@ Apologies if I missed anyone!
 Global changes
 --------------
 
+
+     Various pages use inconsistent terms for 'null byte' (which
+     is the C99/SUSv3 term for the '\0' character).
+
+     To rectify this the following changes were made in the above pages:
+    
+         Replace 'zero byte' with 'null byte'.
+         Replace 'null character' with 'null byte'.
+         Replace 'nulls' with 'null bytes'.
+	 Replace 'NUL-terminated' by 'null-terminated'.
+	 Replace 'NUL' by 'null byte'.
+	 Replace 'terminating NUL' by 'terminating null byte'.
+	 Replace 'final NUL' by 'terminating null byte'.
+	 Replace 'NUL character' by 'null byte'.
+     
 Typographical or grammatical errors have been corrected in several
 places.
 
@@ -27,6 +42,24 @@ epoll_ctl.2
     mtk
         Noted that EPOLLONESHOT was added in 2.6.2.
 	
+gethostname.2
+    mtk
+        Added GLIBC NOTES describing operation of glibc's
+	gethostname() wrapper function.
+
+fmemopen.3
+    mtk
+        Rewrote substantial parts of the page, and relicensed under GPL.
+
+getopt.3
+    mtk
+        Noted historical use of <stdio.h> to declare getopt().
+
 proc.5
     mtk
         Noted that /proc/mounts is pollable since kernel 2.6.15.
+
+	Documented /proc/PID/task.
+
+	Noted that the contents of /proc/PID/{cwd,exe,fd,root,task} 
+	are not available if the main thread has terminated.

man1/cp.1

@@ -254,11 +254,13 @@ Remove each existing destination file before copying.
 With file-utils 4.0 this option was implied by \-f.
 .TP
 .BI "\-\-sparse=" "WHEN"
-A `sparse file' contains `holes' \(em sequences of zero bytes that
-do not occupy any physical disk blocks; the `read' system call
-reads these as zeroes.  This can both save considerable disk space
+A `sparse file' contains `holes' \(em sequences of null bytes ('\\0') that
+do not occupy any physical disk blocks; 
+.BR read (2)
+reads these as null bytes ('\\0').  
+This can both save considerable disk space
 and increase speed, since many binary files contain lots of
-consecutive zero bytes.  By default,
+consecutive null bytes.  By default,
 .B cp
 detects holes in input source files via a crude heuristic
 and makes the corresponding output file sparse as well.

man1/dd.1

@@ -36,8 +36,9 @@ was specified, it writes the amount of data read (which could be smaller
 than what was requested) in a separate output block. This output block
 has precisely the same length as was read unless the
 .B sync
-conversion was specified, in which case the data is padded with NULs
-(or spaces, see below).
+conversion was specified, in which case the data is padded with null
+bytes (NUL, '\\0'; 
+or with spaces, see below).
 .PP
 Otherwise, the input, read one block at a time, is processed
 and the resulting output is collected and written in blocks
@@ -183,7 +184,7 @@ Do not truncate the output file.
 .B sync
 Pad every input block to size of
 .B ibs
-with trailing zero bytes.
+with trailing null bytes ('\\0').
 .RE
 .SH "GNU STANDARD OPTIONS"
 .TP
@@ -206,7 +207,7 @@ Often a tape drive will not accept arbitrarily sized blocks, and
 would get an I/O error for the last fragment of data that does not
 fill an entire block. Use `dd if=myfile of=/dev/mytape conv=sync'
 to get everything on tape. Of course, reading it back will now
-produce a slightly larger file, with nulls added at the end.
+produce a slightly larger file, with null bytes added at the end.
 .SH BUGS
 Commands like `dd if=myfile of=/dev/fd0 bs=1k seek=172' fail
 on some systems because

man2/getdomainname.2

@@ -37,7 +37,7 @@ getdomainname, setdomainname \- get/set domain name
 .SH DESCRIPTION
 These functions are used to access or to change the domain name of the
 current processor.
-If the NUL-terminated domain name requires more than \fIlen\fP bytes,
+If the null-terminated domain name requires more than \fIlen\fP bytes,
 .BR getdomainname ()
 returns the first \fIlen\fP bytes (glibc) or returns an error (libc).
 .SH "RETURN VALUE"

man2/gethostname.2

@@ -42,12 +42,12 @@ These system calls are used to access or to change the host name of the
 current processor.
 The
 .BR gethostname ()
-system call returns a NUL-terminated hostname (set earlier by
+system call returns a null-terminated hostname (set earlier by
 .BR sethostname ())
 in the array \fIname\fP that has a length of \fIlen\fP bytes.
-In case the NUL-terminated hostname does not fit, no error is
+In case the null-terminated hostname does not fit, no error is
 returned, but the hostname is truncated. It is unspecified
-whether the truncated hostname will be NUL-terminated.
+whether the truncated hostname will be null-terminated.
 .SH "RETURN VALUE"
 On success, zero is returned.  On error, \-1 is returned, and
 .I errno
@@ -86,7 +86,7 @@ but not
 .SH NOTES
 SUSv2 guarantees that `Host names are limited to 255 bytes'.
 POSIX 1003.1-2001 guarantees that `Host names (not including
-the terminating NUL) are limited to HOST_NAME_MAX bytes'.
+the terminating null byte) are limited to HOST_NAME_MAX bytes'.
 .SH "GLIBC NOTES"
 The GNU C library implements 
 .BR gethostname () 

man2/listxattr.2

@@ -96,7 +96,7 @@ size of a buffer which is sufficiently large to hold the list of names.
 The
 .I list
 of names is returned as an unordered array of null-terminated character
-strings (attribute names are separated by NUL characters), like this:
+strings (attribute names are separated by null bytes ('\\0')), like this:
 .fam C
 .RS
 .nf

man2/lseek.2

@@ -81,8 +81,8 @@ The
 function allows the file offset to be set beyond the end of the existing
 end-of-file of the file (but this does not change the size of the file).
 If data is later written at this point, subsequent reads of the data
-in the gap return bytes of zeros (until data is actually written into
-the gap).
+in the gap return null bytes ('\\0') until data is actually written into
+the gap.
 .SH "RETURN VALUE"
 Upon successful completion,
 .BR lseek ()

man2/readlink.2

@@ -51,9 +51,7 @@ in the buffer
 which has size
 .IR bufsiz .
 .BR readlink ()
-does not append a
-.B NUL
-character to
+does not append a null byte to
 .IR buf .
 It will truncate the contents (to a length of
 .I bufsiz

man2/stat.2

@@ -118,7 +118,7 @@ The
 field gives the size of the file (if it is a regular 
 file or a symbolic link) in bytes. 
 The size of a symlink is the length of the pathname
-it contains, without trailing NUL.
+it contains, without a trailing null byte.
 
 The
 .I st_blocks

man2/sysfs.2

@@ -50,7 +50,7 @@ into a file-system type index.
 .B 2
 Translate the file-system type index
 .I fs_index
-into a NUL-terminated file-system identifier string. This string will
+into a null-terminated file-system identifier string. This string will
 be written to the buffer pointed to by
 .IR buf .
 Make sure that

man2/truncate.2

@@ -64,7 +64,7 @@ bytes.
 .LP
 If the file previously was larger than this size, the extra data is lost. 
 If the file previously was shorter, it is extended, and
-the extended part reads as zero bytes.
+the extended part reads as null bytes ('\\0').
 .LP
 The file offset is not changed.
 .LP

man2/uname.2

@@ -55,7 +55,7 @@ char domainname[];
 .RE
 The length of the arrays in a
 .I struct utsname
-is unspecified; the fields are NUL-terminated.
+is unspecified; the fields are terminated by a null byte (''\0').
 .SH "RETURN VALUE"
 On success, zero is returned.  On error, \-1 is returned, and
 .I errno

man2/ustat.2

@@ -62,7 +62,7 @@ char	f_fpack[6];	/* Filsys pack name */
 .PP
 
 The last two fields, f_fname and f_fpack, are not implemented and will
-always be filled with NUL characters.
+always be filled with null bytes ('\\0').
 .SH "RETURN VALUE"
 On success, zero is returned and the ustat structure pointed to by
 .I ubuf

man3/argz_add.3

@@ -66,8 +66,8 @@ These functions are glibc-specific.
 .LP
 An argz vector is a pointer to a character buffer together with a length.
 The intended interpretation of the character buffer is array
-of strings, where the strings are separated by NUL bytes.
-If the length is non-zero, the last byte of the buffer must be a NUL.
+of strings, where the strings are separated by null bytes ('\\0').
+If the length is non-zero, the last byte of the buffer must be a null byte.
 .LP
 These functions are for handling argz vectors.
 The pair (NULL,0) is an argz vector, and, conversely,
@@ -111,7 +111,8 @@ will be increased by
 .IR buf_len .)
 .LP
 .BR argz_count ()
-counts the number of strings, that is, the number of NUL bytes, in
+counts the number of strings, that is, 
+the number of null bytes ('\\0'), in
 .RI ( argz , argz_len ).
 .LP
 .BR argz_create ()
@@ -121,7 +122,7 @@ terminated by (char *) 0, into an argz vector
 .RI (* argz ,* argz_len ).
 .LP
 .BR argz_create_sep ()
-converts the NUL-terminated string
+converts the null-terminated string
 .I str
 into an argz vector
 .RI (* argz ,* argz_len )
@@ -193,14 +194,14 @@ will be incremented by the number of replacements.
 is the opposite of
 .BR argz_create_sep ().
 It transforms the argz vector into a normal string by replacing
-all NULs except the last by
+all null bytes ('\\0') except the last by
 .IR sep .
 .SH "RETURN VALUE"
 All argz functions that do memory allocation have a return type of
 \fIerror_t\fP, and return 0 for success, and \fBENOMEM\fP
 if an allocation error occurs.
 .SH BUGS
-Argz vectors without final NUL may lead to Segmentation Faults.
+Argz vectors without a terminating null byte may lead to Segmentation Faults.
 .SH NOTES
 These functions are a GNU extension. Handle with care.
 .SH "SEE ALSO"

man3/asprintf.3

@@ -43,7 +43,7 @@ are analogues of
 and
 .BR vsprintf (),
 except that they allocate a string large enough to hold the output
-including the terminating NUL,
+including the terminating null byte,
 and return a pointer to it via the first parameter.
 This pointer should be passed to
 .BR free (3)

man3/bstring.3

@@ -62,7 +62,7 @@ memmove, memset \- byte string operations
 .fi
 .SH DESCRIPTION
 The byte string functions perform operations on strings (byte arrays)
-that are not necessarily NUL-terminated.  See the individual man pages
+that are not necessarily null-terminated.  See the individual man pages
 for descriptions of each function.
 .SH NOTE
 The functions

man3/bzero.3

@@ -28,7 +28,7 @@
 .\" Modified Tue Oct 22 23:49:37 1996 by Eric S. Raymond <esr@thyrsus.com>
 .TH BZERO 3  2002-12-31 "Linux" "Linux Programmer's Manual"
 .SH NAME
-bzero \- write zero bytes
+bzero \- write zero-valued bytes
 .SH SYNOPSIS
 .nf
 .B #include <strings.h>
@@ -42,7 +42,7 @@ function sets the first
 .I n
 bytes of the byte area starting at
 .I s
-to zero.
+to zero (bytes containing '\\0').
 .SH "RETURN VALUE"
 None.
 .SH "CONFORMING TO"

man3/confstr.3

@@ -72,7 +72,7 @@ copies the value of the string to
 .I buf
 truncated to
 .I len \- 1
-characters if necessary, with a null character as termination.
+characters if necessary, with a null byte ('\\0') as terminator.
 This can be detected by comparing the return value of
 .BR confstr ()
 against

man3/dlopen.3

@@ -191,8 +191,10 @@ fails for any reason, it returns NULL.
 .SS "dlsym"
 The function
 .BR dlsym ()
-takes a "handle" of a dynamic library returned by dlopen and the
-NUL-terminated symbol name, returning the address where that symbol is
+takes a "handle" of a dynamic library returned by 
+.BR dlopen ()
+and the
+null-terminated symbol name, returning the address where that symbol is
 loaded into memory.  If the symbol is not found, in the specified
 library or any of the libraries that were automatically loaded by
 .BR dlopen ()

man3/fwide.3

@@ -41,7 +41,7 @@ current orientation, as above.
 .SH "RETURN VALUE"
 The \fBfwide\fP() function returns the stream's orientation, after possibly
 changing it. A return value > 0 means wide-character oriented. A return value
-< 0 means byte oriented. A return value zero means undecided.
+< 0 means byte oriented. A return value of zero means undecided.
 .SH "CONFORMING TO"
 ISO/ANSI C, UNIX98
 .SH "SEE ALSO"

man3/gethostbyname.3

@@ -180,7 +180,7 @@ The members of the \fIhostent\fP structure are:
 The official name of the host.
 .TP
 .I h_aliases
-A zero-terminated array of alternative names for the host.
+An array of alternative names for the host, terminated by a NULL pointer.
 .TP
 .I h_addrtype
 The type of address; always
@@ -193,8 +193,8 @@ at present.
 The length of the address in bytes.
 .TP
 .I h_addr_list
-A zero-terminated array of network addresses for the host in network byte
-order.
+An array of pointers to network addresses for the host (in network byte
+order), terminated by a NULL pointer.
 .TP
 .I h_addr
 The first address in \fIh_addr_list\fP for backward compatibility.

man3/getline.3

@@ -85,8 +85,8 @@ On success,
 and
 .BR getdelim ()
 return the number of characters read, including the delimiter character,
-but not including the terminating null character. This value can be used
-to handle embedded null characters in the line read.
+but not including the terminating null byte. This value can be used
+to handle embedded null bytes in the line read.
 
 Both functions return \-1  on failure to read a line (including end of file
 condition).

man3/getlogin.3

@@ -88,7 +88,8 @@ The calling process has no controlling tty.
 .TP
 .B ERANGE
 (getlogin_r)
-The length of the user name, including final NUL, is larger than
+The length of the user name, including the terminating null byte, 
+is larger than
 .IR bufsize .
 .LP
 Linux/glibc also has

man3/getnameinfo.3

@@ -89,7 +89,7 @@ stream (TCP) based. This is required for the few ports (512-514)
 that have different services for UDP and TCP.
 .SH "RETURN VALUE"
 On success 0 is returned, and node and service names, if requested,
-are filled with NUL-terminated strings, possibly truncated to fit
+are filled with null-terminated strings, possibly truncated to fit
 the specified buffer lengths.
 On error one of the following non-zero error codes is returned:
 .TP

man3/getpass.3

@@ -45,7 +45,7 @@ The function
 .BR getpass ()
 returns a pointer to a static buffer containing the
 (first PASS_MAX bytes of) the password without the trailing
-newline, terminated by a NUL.
+newline, terminated by a null byte ('\\0').
 This buffer may be overwritten by a following call.
 On error, the terminal state is restored,
 .I errno

man3/hsearch.3

@@ -77,7 +77,7 @@ The argument \fIitem\fP is of type \fBENTRY\fP, which is a typedef defined in
 	} ENTRY;
 .fi
 .sp
-The field \fIkey\fP points to the NUL-terminated string which is the
+The field \fIkey\fP points to the null-terminated string which is the
 search key.
 The field \fIdata\fP points to the data associated with that key.
 The function \fBhsearch\fP() searches the hash table for an

man3/perror.3

@@ -51,7 +51,7 @@ First (if
 .I s
 is not NULL and
 .RI * s
-is not NUL) the argument string
+is not a null byte ('\\0')) the argument string
 .I s
 is printed, followed by a colon and a blank.
 Then the message and a new-line.

man3/printf.3

@@ -642,14 +642,11 @@ modifier is present: The
 .I "const char *"
 argument is expected to be a pointer to an array of character type (pointer
 to a string).  Characters from the array are written up to (but not
-including) a terminating
-.B NUL
-character; if a precision is specified, no more than the number specified
-are written.  If a precision is given, no null character need be present;
+including) a terminating null byte ('\\0');
+if a precision is specified, no more than the number specified
+are written.  If a precision is given, no null byte need be present;
 if the precision is not specified, or is greater than the size of the
-array, the array must contain a terminating
-.B NUL
-character.
+array, the array must contain a terminating null byte.
 
 If an
 .B l

man3/readdir.3

@@ -67,7 +67,7 @@ structure contains a field
 .I "char d_name[]"
 of unspecified size, with at most
 .B NAME_MAX
-characters preceding the terminating null character.
+characters preceding the terminating null byte.
 POSIX 1003.1-2001 also documents the field
 .I "ino_t d_ino"
 as an XSI extension.
@@ -76,7 +76,9 @@ as an XSI extension.
 The data returned by \fBreaddir\fP() may be overwritten by subsequent
 calls to \fBreaddir\fP() for the same directory stream.
 .SH "RETURN VALUE"
-The \fBreaddir\fP() function returns a pointer to a dirent structure, or
+The \fBreaddir\fP() function returns a pointer to a 
+.I dirent 
+structure, or
 NULL if an error occurs or end-of-file is reached.
 On error,
 .I errno

man3/scanf.3

@@ -440,7 +440,7 @@ Matches a sequence of characters whose length is specified by the
 (default 1); the next pointer must be a pointer to
 .IR char ,
 and there must be enough room for all the characters (no terminating
-null character
+null byte
 is added).  The usual skip of leading white space is suppressed.  To skip
 white space first, use an explicit space in the format.
 .TP
@@ -449,7 +449,7 @@ Matches a nonempty sequence of characters from the specified set of
 accepted characters; the next pointer must be a pointer to
 .IR char ,
 and there must be enough room for all the characters in the string, plus a
-terminating null character.
+terminating null byte.
 The usual skip of leading white space is suppressed.  The
 string is to be made up of characters in (or not in) a particular set; the
 set is defined by the characters between the open bracket

man3/stpcpy.3

@@ -40,7 +40,7 @@ The \fBstpcpy\fP() function copies the string pointed to by \fIsrc\fP
 \fIdest\fP must be large enough to receive the copy.
 .SH "RETURN VALUE"
 \fBstpcpy\fP() returns a pointer to the \fBend\fP of the string
-\fIdest\fP (that is, the address of the terminating null character)
+\fIdest\fP (that is, the address of the terminating null byte)
 rather than the beginning.
 .SH EXAMPLE
 For example, this program uses \fBstpcpy\fP() to concatenate \fBfoo\fP and

man3/strdup.3

@@ -53,7 +53,7 @@ obtained with \fBmalloc\fP(3), and can be freed with \fBfree\fP(3).
 
 The \fBstrndup\fP() function is similar, but only copies at most
 \fIn\fP characters. If \fIs\fP is longer than \fIn\fP, only \fIn\fP
-characters are copied, and a terminating NUL is added.
+characters are copied, and a terminating null byte ('\\0') is added.
 
 \fBstrdupa\fP() and \fBstrndupa\fP() are similar, but use \fBalloca(3)\fP
 to allocate the buffer. They are only available when using the GNU

man3/strfmon.3

@@ -102,8 +102,8 @@ One argument of type double is converted using the locale's
 national currency format.
 .SH "RETURN VALUE"
 The \fBstrfmon\fP() function returns the number of characters placed
-in the array \fIs\fP, not including the terminating NUL character,
-provided the string, including the terminating NUL, fits.
+in the array \fIs\fP, not including the terminating null byte,
+provided the string, including the terminating null byte, fits.
 Otherwise, it sets
 .I errno
 to E2BIG, returns \-1, and the contents of the array is undefined.

man3/strftime.3

@@ -237,8 +237,8 @@ See also
 .BR ctime (3).
 .SH "RETURN VALUE"
 The \fBstrftime\fP() function returns the number of characters placed
-in the array \fIs\fP, not including the terminating NUL character,
-provided the string, including the terminating NUL, fits.
+in the array \fIs\fP, not including the terminating null byte,
+provided the string, including the terminating null byte, fits.
 Otherwise, it returns 0, and the contents of the array is undefined.
 (Thus at least since libc 4.4.4; very old versions of libc,
 such as libc 4.4.1, would return \fImax\fP if the array was too small.)

man3/string.3

@@ -84,7 +84,7 @@ strrchr, strsep, strspn, strstr, strtok, strxfrm, index, rindex
 .BI "size_t strxfrm(char *" dest ", const char *" src ", size_t " n );
 .fi
 .SH DESCRIPTION
-The string functions perform string operations on NUL-terminated
+The string functions perform string operations on null-terminated
 strings.  See the individual man pages for descriptions of each
 function.
 .SH "SEE ALSO"

man3/strptime.3

@@ -259,7 +259,7 @@ The return value of the function is a pointer to the first character
 not processed in this function call.  In case the input string
 contains more characters than required by the format string the return
 value points right after the last consumed input character.  In case
-the whole input string is consumed the return value points to the NUL
+the whole input string is consumed the return value points to the null
 byte at the end of the string.  If \fBstrptime\fP() fails to match all
 of the format string and therefore an error occurred the function
 returns NULL.

man3/sysconf.3

@@ -133,12 +133,13 @@ The max number of simultaneous processes per user ID.
 Must not be less than _POSIX_CHILD_MAX (25).
 .TP
 .BR HOST_NAME_MAX " - " _SC_HOST_NAME_MAX
-Max length of a hostname, not including the final NUL, as returned by
+Max length of a hostname, not including the terminating null byte, 
+as returned by
 .BR gethostname (2).
 Must not be less than _POSIX_HOST_NAME_MAX (255).
 .TP
 .BR LOGIN_NAME_MAX " - " _SC_LOGIN_NAME_MAX
-Maximum length of a login name, including the final NUL.
+Maximum length of a login name, including the terminating null byte.
 Must not be less than _POSIX_LOGIN_NAME_MAX (9).
 .TP
 .BR "" "clock ticks - " _SC_CLK_TCK
@@ -175,7 +176,8 @@ The maximum number of symbolic links seen in a pathname before resolution
 returns ELOOP. Must not be less than _POSIX_SYMLOOP_MAX (8).
 .TP
 .BR TTY_NAME_MAX " - " _SC_TTY_NAME_MAX
-The maximum length of terminal device name, including final NUL.
+The maximum length of terminal device name, 
+including the terminating null byte.
 Must not be less than _POSIX_TTY_NAME_MAX (9).
 .TP
 .BR TZNAME_MAX " - " _SC_TZNAME_MAX

man3/termios.3

@@ -98,7 +98,7 @@ queues to be flushed, and if the terminal is the controlling
 terminal of a foreground process group, it will cause a
 \fBSIGINT\fP to be sent to this foreground process group.
 When neither \fBIGNBRK\fP nor \fBBRKINT\fP are set, a BREAK
-reads as a NUL character, except when \fBPARMRK\fP is set,
+reads as a null byte ('\\0'), except when \fBPARMRK\fP is set,
 in which case it reads as the sequence \\377 \\0 \\0.
 .TP
 .B IGNPAR
@@ -169,7 +169,7 @@ Send fill characters for a delay, rather than using a timed delay.
 .TP
 .B OFDEL
 (not in POSIX) Fill character is ASCII DEL (0177).
-If unset, fill character is ASCII NUL.
+If unset, fill character is ASCII NUL ('\\0').
 .TP
 .B NLDLY
 Newline delay mask.  Values are \fBNL0\fP and \fBNL1\fP.

man3/ttyname.3

@@ -37,7 +37,7 @@ ttyname, ttyname_r \- return name of a terminal
 .SH DESCRIPTION
 The function
 .BR ttyname ()
-returns a pointer to the NUL-terminated pathname of the terminal device
+returns a pointer to the null-terminated pathname of the terminal device
 that is open on the file descriptor \fIfd\fP, or NULL on error
 (for example, if \fIfd\fP is not connected to a terminal).
 The return value may point to static data, possibly overwritten by the

man4/dsp56k.4

@@ -77,7 +77,7 @@ DSP56001.
 sets the receive word size.  Allowed values are in the range 1 to 4,
 and is the number of bytes that will be received at a time from the
 DSP56001.  These data quantities will either truncated, or padded with
-a zero byte to fit the native 24-bit data format of the DSP56001.
+a null byte ('\\0') to fit the native 24-bit data format of the DSP56001.
 .IP \fBDSP56K_HOST_FLAGS\fP
 read and write the host flags.  The host flags are four
 general-purpose bits that can be read by both the hosting computer and

man4/tty_ioctl.4

@@ -268,8 +268,9 @@ Can be applied to the master side of a pseudo-terminal only (and will return
 ENOTTY otherwise). In packet mode, each subsequent
 .BR read (2)
 will return a packet that either contains a single non-zero control byte,
-or has a single zero byte followed by data written on the slave side of
-the pty. If the first byte is not TIOCPKT_DATA (0), it is an OR of one
+or has a single byte containing zero (''\0') followed by data 
+written on the slave side of the pty. 
+If the first byte is not TIOCPKT_DATA (0), it is an OR of one
 or more of the following bits:
 
 .nf

man5/elf.5

@@ -1149,9 +1149,9 @@ and section names.
 One references a string as an index into the string
 table section.
 The first byte, which is index zero, is defined to hold
-a null character.
+a null byte ('\\0').
 Similarly, a string table's last byte is defined to
-hold a null character, ensuring null termination for all strings.
+hold a null byte, ensuring null termination for all strings.
 .Pp
 An object file's symbol table holds information needed to locate and
 relocate a program's symbolic definitions and references.

man5/proc.5

@@ -108,8 +108,8 @@ are not available if the main thread has already terminated
 .TP
 .I /proc/[number]/environ
 This file contains the environment for the process.
-The entries are separated by null characters,
-and there may be a null character at the end.
+The entries are separated by null bytes ('\\0'),
+and there may be a null bytes at the end.
 Thus, to print out the environment of process 1, you would do:
 
 .br
@@ -1702,7 +1702,8 @@ This is useful for analysing virtual memory behaviour.
 .I /usr/src/linux/Documentation/filesystems/proc.txt
 .SH CAVEATS
 Note that many strings (i.e., the environment and command line) are in
-the internal format, with sub-fields terminated by NUL bytes, so you
+the internal format, with sub-fields terminated by null bytes ('\\0'), 
+so you
 may find that things are more readable if you use \fIod \-c\fP or \fItr
 "\\000" "\\n"\fP to read them.
 Alternatively, \fIecho `cat <file>`\fP works well.

man5/termcap.5

@@ -95,7 +95,7 @@ hc	This is a hardcopy terminal
 HC	The cursor is hard to see when not on bottom line
 hs	Has a status line
 hz	Hazeltine bug, the terminal can not print tilde characters
-in	Terminal inserts nulls, not spaces, to fill whitespace
+in	Terminal inserts null bytes, not spaces, to fill whitespace
 km	Terminal has a meta key
 mi	Cursor movement works in insert mode
 ms	Cursor movement works in standout/underline mode

man7/charsets.7

@@ -237,7 +237,7 @@ which can be quite large for 16-bit codes.
 Note that UTF-8 is self-synchronizing: 10xxxxxx is a tail, any other
 byte is the head of a code.  Note that the only way ASCII bytes occur
 in a UTF-8 stream, is as themselves. In particular, there are no
-embedded NULs or '/'s that form part of some larger code.
+embedded NULs ('\\0') or '/'s that form part of some larger code.
 .LP
 Since ASCII, and, in particular, NUL and '/', are unchanged, the
 kernel does not notice that UTF-8 is being used. It does not care at

man7/unix.7

@@ -79,7 +79,8 @@ always contains
 contains the zero-terminated pathname of the socket in the file system.
 If 
 .B sun_path
-starts with a zero byte it refers to the abstract namespace maintained by
+starts with a null byte (''\0'), 
+then it refers to the abstract namespace maintained by
 the Unix protocol module.
 The socket's address in this namespace is given by the rest of the 
 bytes in