mirror of https://github.com/mkerrisk/man-pages
1463 lines
47 KiB
Groff
1463 lines
47 KiB
Groff
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "ED" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" ed
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.SH NAME
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ed \- edit text
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.SH SYNOPSIS
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.LP
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\fBed\fP \fB[\fP\fB-p\fP \fIstring\fP\fB][\fP\fB-s\fP\fB][\fP\fIfile\fP\fB]\fP
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.SH DESCRIPTION
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.LP
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The \fIed\fP utility is a line-oriented text editor that uses two
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modes: \fIcommand mode\fP and \fIinput mode\fP. In command
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mode the input characters shall be interpreted as commands, and in
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input mode they shall be interpreted as text. See the EXTENDED
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DESCRIPTION section.
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.SH OPTIONS
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.LP
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The \fIed\fP utility shall conform to the Base Definitions volume
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of IEEE\ Std\ 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
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.LP
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The following options shall be supported:
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.TP 7
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\fB-p\ \fP \fIstring\fP
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Use \fIstring\fP as the prompt string when in command mode. By default,
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there shall be no prompt string.
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.TP 7
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\fB-s\fP
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Suppress the writing of byte counts by \fBe\fP, \fBE\fP, \fBr\fP,
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and \fBw\fP commands and of the \fB'!'\fP prompt after
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a !\fIcommand\fP.
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.sp
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.SH OPERANDS
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.LP
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The following operand shall be supported:
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.TP 7
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\fIfile\fP
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If the \fIfile\fP argument is given, \fIed\fP shall simulate an \fBe\fP
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command on the file named by the pathname,
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\fIfile\fP, before accepting commands from the standard input. If
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the \fIfile\fP operand is \fB'-'\fP , the results are
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unspecified.
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.sp
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.SH STDIN
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.LP
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The standard input shall be a text file consisting of commands, as
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described in the EXTENDED DESCRIPTION section.
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.SH INPUT FILES
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.LP
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The input files shall be text files.
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.SH ENVIRONMENT VARIABLES
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.LP
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The following environment variables shall affect the execution of
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\fIed\fP:
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.TP 7
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\fIHOME\fP
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Determine the pathname of the user's home directory.
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.TP 7
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\fILANG\fP
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Provide a default value for the internationalization variables that
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are unset or null. (See the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, Section 8.2, Internationalization Variables
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for
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the precedence of internationalization variables used to determine
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the values of locale categories.)
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.TP 7
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\fILC_ALL\fP
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If set to a non-empty string value, override the values of all the
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other internationalization variables.
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.TP 7
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\fILC_COLLATE\fP
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.sp
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Determine the locale for the behavior of ranges, equivalence classes,
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and multi-character collating elements within regular
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expressions.
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.TP 7
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\fILC_CTYPE\fP
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Determine the locale for the interpretation of sequences of bytes
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of text data as characters (for example, single-byte as
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opposed to multi-byte characters in arguments and input files) and
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the behavior of character classes within regular
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expressions.
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.TP 7
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\fILC_MESSAGES\fP
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Determine the locale that should be used to affect the format and
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contents of diagnostic messages written to standard error and
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informative messages written to standard output.
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.TP 7
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\fINLSPATH\fP
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Determine the location of message catalogs for the processing of \fILC_MESSAGES
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\&.\fP
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.sp
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.SH ASYNCHRONOUS EVENTS
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.LP
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The \fIed\fP utility shall take the standard action for all signals
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(see the ASYNCHRONOUS EVENTS section in \fIUtility Description Defaults\fP
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) with the following exceptions:
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.TP 7
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SIGINT
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The \fIed\fP utility shall interrupt its current activity, write the
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string \fB"?\\n"\fP to standard output, and return to
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command mode (see the EXTENDED DESCRIPTION section).
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.TP 7
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SIGHUP
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If the buffer is not empty and has changed since the last write, the
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\fIed\fP utility shall attempt to write a copy of the
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buffer in a file. First, the file named \fBed.hup\fP in the current
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directory shall be used; if that fails, the file named
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\fBed.hup\fP in the directory named by the \fIHOME\fP environment
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variable shall be used. In any case, the \fIed\fP utility
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shall exit without returning to command mode.
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.TP 7
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SIGQUIT
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The \fIed\fP utility shall ignore this event.
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.sp
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.SH STDOUT
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.LP
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Various editing commands and the prompting feature (see \fB-p\fP)
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write to standard output, as described in the EXTENDED
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DESCRIPTION section.
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.SH STDERR
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.LP
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The standard error shall be used only for diagnostic messages.
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.SH OUTPUT FILES
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.LP
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The output files shall be text files whose formats are dependent on
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the editing commands given.
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.SH EXTENDED DESCRIPTION
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.LP
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The \fIed\fP utility shall operate on a copy of the file it is editing;
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changes made to the copy shall have no effect on the
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file until a \fBw\fP (write) command is given. The copy of the text
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is called the \fIbuffer\fP.
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.LP
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Commands to \fIed\fP have a simple and regular structure: zero, one,
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or two \fIaddresses\fP followed by a single-character
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\fIcommand\fP, possibly followed by parameters to that command. These
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addresses specify one or more lines in the buffer. Every
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command that requires addresses has default addresses, so that the
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addresses very often can be omitted. If the \fB-p\fP option is
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specified, the prompt string shall be written to standard output before
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each command is read.
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.LP
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In general, only one command can appear on a line. Certain commands
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allow text to be input. This text is placed in the
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appropriate place in the buffer. While \fIed\fP is accepting text,
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it is said to be in \fIinput mode\fP. In this mode, no
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commands shall be recognized; all input is merely collected. Input
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mode is terminated by entering a line consisting of two
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characters: a period ( \fB'.'\fP ) followed by a <newline>. This line
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is not considered part of the input text.
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.SS Regular Expressions in ed
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.LP
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The \fIed\fP utility shall support basic regular expressions, as described
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in the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, Section 9.3, Basic Regular Expressions. Since
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regular expressions in \fIed\fP are always matched against single
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lines (excluding the terminating <newline>s), never
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against any larger section of text, there is no way for a regular
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expression to match a <newline>.
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.LP
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A null RE shall be equivalent to the last RE encountered.
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.LP
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Regular expressions are used in addresses to specify lines, and in
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some commands (for example, the \fBs\fP substitute command)
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to specify portions of a line to be substituted.
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.SS Addresses in ed
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.LP
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Addressing in \fIed\fP relates to the current line. Generally, the
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current line is the last line affected by a command. The
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current line number is the address of the current line. If the edit
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buffer is not empty, the initial value for the current line
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shall be the last line in the edit buffer; otherwise, zero.
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.LP
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Addresses shall be constructed as follows:
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.IP " 1." 4
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The period character ( \fB'.'\fP ) shall address the current line.
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.LP
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.IP " 2." 4
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The dollar sign character ( \fB'$'\fP ) shall address the last line
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of the edit buffer.
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.LP
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.IP " 3." 4
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The positive decimal number \fIn\fP shall address the \fIn\fPth line
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of the edit buffer.
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.LP
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.IP " 4." 4
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The apostrophe-x character pair ( \fB"'x"\fP ) shall address the line
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marked with the mark name character \fIx\fP, which
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shall be a lowercase letter from the portable character set. It shall
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be an error if the character has not been set to mark a line
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or if the line that was marked is not currently present in the edit
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buffer.
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.LP
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.IP " 5." 4
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A BRE enclosed by slash characters ( \fB'/'\fP ) shall address the
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first line found by searching forwards from the line
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following the current line toward the end of the edit buffer and stopping
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at the first line for which the line excluding the
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terminating <newline> matches the BRE. The BRE consisting of a null
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BRE delimited by a pair of slash characters shall address
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the next line for which the line excluding the terminating <newline>
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matches the last BRE encountered. In addition, the
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second slash can be omitted at the end of a command line. Within the
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BRE, a backslash-slash pair ( \fB"\\/"\fP ) shall represent
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a literal slash instead of the BRE delimiter. If necessary, the search
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shall wrap around to the beginning of the buffer and
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continue up to and including the current line, so that the entire
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buffer is searched.
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.LP
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.IP " 6." 4
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A BRE enclosed by question-mark characters ( \fB'?'\fP ) shall address
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the first line found by searching backwards from the
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line preceding the current line toward the beginning of the edit buffer
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and stopping at the first line for which the line excluding
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the terminating <newline> matches the BRE. The BRE consisting of a
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null BRE delimited by a pair of question-mark characters (
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\fB"??"\fP ) shall address the previous line for which the line excluding
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the terminating <newline> matches the last BRE
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encountered. In addition, the second question-mark can be omitted
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at the end of a command line. Within the BRE, a
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backslash-question-mark pair ( \fB"\\?"\fP ) shall represent a literal
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question mark instead of the BRE delimiter. If necessary,
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the search shall wrap around to the end of the buffer and continue
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up to and including the current line, so that the entire buffer
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is searched.
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.LP
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.IP " 7." 4
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A plus-sign ( \fB'+'\fP ) or hyphen character ( \fB'-'\fP ) followed
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by a decimal number shall address the current line
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plus or minus the number. A plus-sign or hyphen character not followed
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by a decimal number shall address the current line plus or
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minus 1.
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.LP
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.LP
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Addresses can be followed by zero or more address offsets, optionally
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<blank>-separated. Address offsets are constructed
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as follows:
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.IP " *" 3
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A plus-sign or hyphen character followed by a decimal number shall
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add or subtract, respectively, the indicated number of lines
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to or from the address. A plus-sign or hyphen character not followed
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by a decimal number shall add or subtract 1 to or from the
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address.
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.LP
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.IP " *" 3
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A decimal number shall add the indicated number of lines to the address.
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.LP
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.LP
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It shall not be an error for an intermediate address value to be less
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than zero or greater than the last line in the edit
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buffer. It shall be an error for the final address value to be less
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than zero or greater than the last line in the edit buffer. It
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shall be an error if a search for a BRE fails to find a matching line.
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.LP
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Commands accept zero, one, or two addresses. If more than the required
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number of addresses are provided to a command that
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requires zero addresses, it shall be an error. Otherwise, if more
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than the required number of addresses are provided to a command,
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the addresses specified first shall be evaluated and then discarded
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until the maximum number of valid addresses remain, for the
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specified command.
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.LP
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Addresses shall be separated from each other by a comma ( \fB','\fP
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) or semicolon character ( \fB';'\fP ). In the case of
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a semicolon separator, the current line ( \fB'.'\fP ) shall be set
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to the first address, and only then will the second address
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be calculated. This feature can be used to determine the starting
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line for forwards and backwards searches; see rules 5. and 6.
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.LP
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Addresses can be omitted on either side of the comma or semicolon
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separator, in which case the resulting address pairs shall be
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as follows:
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.TS C
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center; l l.
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\fBSpecified\fP \fBResulting\fP
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, 1 , $
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, addr 1 , addr
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addr , addr , addr
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; . ; $
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; addr . ; addr
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addr ; addr ; addr
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.TE
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.LP
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Any <blank>s included between addresses, address separators, or address
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offsets shall be ignored.
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.SS Commands in ed
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.LP
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In the following list of \fIed\fP commands, the default addresses
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are shown in parentheses. The number of addresses shown in
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the default shall be the number expected by the command. The parentheses
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are not part of the address; they show that the given
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addresses are the default.
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.LP
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It is generally invalid for more than one command to appear on a line.
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However, any command (except \fBe\fP, \fBE\fP,
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\fBf\fP, \fBq\fP, \fBQ\fP, \fBr\fP, \fBw\fP, and \fB!\fP) can be suffixed
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by the letter \fBl\fP, \fBn\fP, or \fBp\fP; in
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which case, except for the \fBl\fP, \fBn\fP, and \fBp\fP commands,
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the command shall be executed and then the new current line
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shall be written as described below under the \fBl\fP, \fBn\fP, and
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\fBp\fP commands. When an \fBl\fP, \fBn\fP, or \fBp\fP
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suffix is used with an \fBl\fP, \fBn\fP, or \fBp\fP command, the command
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shall write to standard output as described below, but
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it is unspecified whether the suffix writes the current line again
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in the requested format or whether the suffix has no effect. For
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example, the \fBpl\fP command (base \fBp\fP command with an \fBl\fP
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suffix) shall either write just the current line or write it
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twice-once as specified for \fBp\fP and once as specified for \fBl\fP.
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Also, the \fBg\fP, \fBG\fP, \fBv\fP, and \fBV\fP
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commands shall take a command as a parameter.
|
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.LP
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Each address component can be preceded by zero or more <blank>s. The
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command letter can be preceded by zero or more
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<blank>s. If a suffix letter ( \fBl\fP, \fBn\fP, or \fBp\fP) is given,
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the application shall ensure that it immediately
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follows the command.
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.LP
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The \fBe\fP, \fBE\fP, \fBf\fP, \fBr\fP, and \fBw\fP commands shall
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take an optional \fIfile\fP parameter, separated from
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the command letter by one or more <blank>s.
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.LP
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If changes have been made in the buffer since the last \fBw\fP command
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that wrote the entire buffer, \fIed\fP shall warn the
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user if an attempt is made to destroy the editor buffer via the \fBe\fP
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or \fBq\fP commands. The \fIed\fP utility shall write
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the string:
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.sp
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.RS
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.nf
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\fB"?\\n"
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\fP
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.fi
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.RE
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.LP
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(followed by an explanatory message if \fIhelp mode\fP has been enabled
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via the \fBH\fP command) to standard output and shall
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continue in command mode with the current line number unchanged. If
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the \fBe\fP or \fBq\fP command is repeated with no
|
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intervening command, it shall take effect.
|
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.LP
|
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If a terminal disconnect is detected:
|
|
.IP " *" 3
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If the buffer is not empty and has changed since the last write, the
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\fIed\fP utility shall attempt to write a copy of the
|
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buffer to a file named \fBed.hup\fP in the current directory. If this
|
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write fails, \fIed\fP shall attempt to write a copy of the
|
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buffer to a filename \fBed.hup\fP in the directory named by the \fIHOME\fP
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environment variable. If both these attempts fail,
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\fIed\fP shall exit without saving the buffer.
|
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.LP
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.IP " *" 3
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The \fIed\fP utility shall not write the file to the currently remembered
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pathname or return to command mode, and shall
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terminate with a non-zero exit status.
|
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.LP
|
|
.LP
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|
If an end-of-file is detected on standard input:
|
|
.IP " *" 3
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|
If the \fIed\fP utility is in input mode, \fIed\fP shall terminate
|
|
input mode and return to command mode. It is unspecified if
|
|
any partially entered lines (that is, input text without a terminating
|
|
<newline>) are discarded from the input text.
|
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.LP
|
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.IP " *" 3
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If the \fIed\fP utility is in command mode, it shall act as if a \fBq\fP
|
|
command had been entered.
|
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.LP
|
|
.LP
|
|
If the closing delimiter of an RE or of a replacement string (for
|
|
example, \fB'/'\fP ) in a \fBg\fP, \fBG\fP, \fBs\fP,
|
|
\fBv\fP, or \fBV\fP command would be the last character before a <newline>,
|
|
that delimiter can be omitted, in which case
|
|
the addressed line shall be written. For example, the following pairs
|
|
of commands are equivalent:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBs/s1/s2 s/s1/s2/p
|
|
g/s1 g/s1/p
|
|
?s1 ?s1?
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|
\fP
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|
.fi
|
|
.RE
|
|
.LP
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|
If an invalid command is entered, \fIed\fP shall write the string:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"?\\n"
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|
\fP
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|
.fi
|
|
.RE
|
|
.LP
|
|
(followed by an explanatory message if \fIhelp mode\fP has been enabled
|
|
via the \fBH\fP command) to standard output and shall
|
|
continue in command mode with the current line number unchanged.
|
|
.SS Append Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.)a
|
|
<\fP\fItext\fP\fB>
|
|
\&.
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBa\fP command shall read the given text and append it after
|
|
the addressed line; the current line number shall become the
|
|
address of the last inserted line or, if there were none, the addressed
|
|
line. Address 0 shall be valid for this command; it shall
|
|
cause the appended text to be placed at the beginning of the buffer.
|
|
.SS Change Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)c
|
|
<\fP\fItext\fP\fB>
|
|
\&.
|
|
\fP
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|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBc\fP command shall delete the addressed lines, then accept
|
|
input text that replaces these lines; the current line shall
|
|
be set to the address of the last line input; or, if there were none,
|
|
at the line after the last line deleted; if the lines deleted
|
|
were originally at the end of the buffer, the current line number
|
|
shall be set to the address of the new last line; if no lines
|
|
remain in the buffer, the current line number shall be set to zero.
|
|
Address 0 shall be valid for this command; it shall be
|
|
interpreted as if address 1 were specified.
|
|
.SS Delete Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)d
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBd\fP command shall delete the addressed lines from the buffer.
|
|
The address of the line after the last line deleted shall
|
|
become the current line number; if the lines deleted were originally
|
|
at the end of the buffer, the current line number shall be set
|
|
to the address of the new last line; if no lines remain in the buffer,
|
|
the current line number shall be set to zero.
|
|
.SS Edit Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBe\fP \fB[\fP\fIfile\fP\fB]\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBe\fP command shall delete the entire contents of the buffer
|
|
and then read in the file named by the pathname \fIfile\fP.
|
|
The current line number shall be set to the address of the last line
|
|
of the buffer. If no pathname is given, the currently
|
|
remembered pathname, if any, shall be used (see the \fBf\fP command).
|
|
The number of bytes read shall be written to standard
|
|
output, unless the \fB-s\fP option was specified, in the following
|
|
format:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"%d\\n", <\fP\fInumber of bytes read\fP\fB>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
The name \fIfile\fP shall be remembered for possible use as a default
|
|
pathname in subsequent \fBe\fP, \fBE\fP, \fBr\fP, and
|
|
\fBw\fP commands. If \fIfile\fP is replaced by \fB'!'\fP , the rest
|
|
of the line shall be taken to be a shell command line
|
|
whose output is to be read. Such a shell command line shall not be
|
|
remembered as the current \fIfile\fP. All marks shall be
|
|
discarded upon the completion of a successful \fBe\fP command. If
|
|
the buffer has changed since the last time the entire buffer was
|
|
written, the user shall be warned, as described previously.
|
|
.SS Edit Without Checking Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBE\fP \fB[\fP\fIfile\fP\fB]\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBE\fP command shall possess all properties and restrictions
|
|
of the \fBe\fP command except that the editor shall not
|
|
check to see whether any changes have been made to the buffer since
|
|
the last \fBw\fP command.
|
|
.SS Filename Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBf\fP \fB[\fP\fIfile\fP\fB]\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
If \fIfile\fP is given, the \fBf\fP command shall change the currently
|
|
remembered pathname to \fIfile\fP; whether the name is
|
|
changed or not, it shall then write the (possibly new) currently remembered
|
|
pathname to the standard output in the following
|
|
format:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"%s\\n", <\fP\fIpathname\fP\fB>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
The current line number shall be unchanged.
|
|
.SS Global Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(1,$)g/\fP\fIRE\fP\fB/\fP\fIcommand list\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
In the \fBg\fP command, the first step shall be to mark every line
|
|
for which the line excluding the terminating <newline>
|
|
matches the given RE. Then, going sequentially from the beginning
|
|
of the file to the end of the file, the given \fIcommand list\fP
|
|
shall be executed for each marked line, with the current line number
|
|
set to the address of that line. Any line modified by the
|
|
\fIcommand list\fP shall be unmarked. When the \fBg\fP command completes,
|
|
the current line number shall have the value assigned
|
|
by the last command in the \fIcommand list\fP. If there were no matching
|
|
lines, the current line number shall not be changed. A
|
|
single command or the first of a list of commands shall appear on
|
|
the same line as the global command. All lines of a multi-line
|
|
list except the last line shall be ended with a backslash preceding
|
|
the terminating <newline>; the \fBa\fP, \fBi\fP, and
|
|
\fBc\fP commands and associated input are permitted. The \fB'.'\fP
|
|
terminating input mode can be omitted if it would be the
|
|
last line of the \fIcommand list\fP. An empty \fIcommand list\fP shall
|
|
be equivalent to the \fBp\fP command. The use of the
|
|
\fBg\fP, \fBG\fP, \fBv\fP, \fBV\fP, and \fB!\fP commands in the \fIcommand
|
|
list\fP produces undefined results. Any character
|
|
other than <space> or <newline> can be used instead of a slash to
|
|
delimit the RE. Within the RE, the RE delimiter
|
|
itself can be used as a literal character if it is preceded by a backslash.
|
|
.SS Interactive Global Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(1,$)G/\fP\fIRE\fP\fB/
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
In the \fBG\fP command, the first step shall be to mark every line
|
|
for which the line excluding the terminating <newline>
|
|
matches the given RE. Then, for every such line, that line shall be
|
|
written, the current line number shall be set to the address of
|
|
that line, and any one command (other than one of the \fBa\fP, \fBc\fP,
|
|
\fBi\fP, \fBg\fP, \fBG\fP, \fBv\fP, and \fBV\fP
|
|
commands) shall be read and executed. A <newline> shall act as a null
|
|
command (causing no action to be taken on the current
|
|
line); an \fB'&'\fP shall cause the re-execution of the most recent
|
|
non-null command executed within the current invocation
|
|
of \fBG\fP. Note that the commands input as part of the execution
|
|
of the \fBG\fP command can address and affect any lines in the
|
|
buffer. Any line modified by the command shall be unmarked. The final
|
|
value of the current line number shall be the value set by
|
|
the last command successfully executed. (Note that the last command
|
|
successfully executed shall be the \fBG\fP command itself if a
|
|
command fails or the null command is specified.) If there were no
|
|
matching lines, the current line number shall not be changed. The
|
|
\fBG\fP command can be terminated by a SIGINT signal. Any character
|
|
other than <space> or <newline> can be used
|
|
instead of a slash to delimit the RE and the replacement. Within the
|
|
RE, the RE delimiter itself can be used as a literal character
|
|
if it is preceded by a backslash.
|
|
.SS Help Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBh
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBh\fP command shall write a short message to standard output
|
|
that explains the reason for the most recent \fB'?'\fP
|
|
notification. The current line number shall be unchanged.
|
|
.SS Help-Mode Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBH
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBH\fP command shall cause \fIed\fP to enter a mode in which
|
|
help messages (see the \fBh\fP command) shall be written to
|
|
standard output for all subsequent \fB'?'\fP notifications. The \fBH\fP
|
|
command alternately shall turn this mode on and off; it
|
|
is initially off. If the help-mode is being turned on, the \fBH\fP
|
|
command also explains the previous \fB'?'\fP notification,
|
|
if there was one. The current line number shall be unchanged.
|
|
.SS Insert Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.)i
|
|
<\fP\fItext\fP\fB>
|
|
\&.
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBi\fP command shall insert the given text before the addressed
|
|
line; the current line is set to the last inserted line
|
|
or, if there was none, to the addressed line. This command differs
|
|
from the \fBa\fP command only in the placement of the input
|
|
text. Address 0 shall be valid for this command; it shall be interpreted
|
|
as if address 1 were specified.
|
|
.SS Join Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.+1)j
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBj\fP command shall join contiguous lines by removing the appropriate
|
|
<newline>s. If exactly one address is given,
|
|
this command shall do nothing. If lines are joined, the current line
|
|
number shall be set to the address of the joined line;
|
|
otherwise, the current line number shall be unchanged.
|
|
.SS Mark Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.)k\fP\fIx\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBk\fP command shall mark the addressed line with name \fIx\fP,
|
|
which the application shall ensure is a lowercase letter
|
|
from the portable character set. The address \fB"'x"\fP shall then
|
|
refer to this line; the current line number shall be
|
|
unchanged.
|
|
.SS List Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)l
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBl\fP command shall write to standard output the addressed lines
|
|
in a visually unambiguous form. The characters listed in
|
|
the Base Definitions volume of IEEE\ Std\ 1003.1-2001, Table 5-1,
|
|
Escape Sequences and Associated Actions ( \fB'\\\\'\fP ,
|
|
\fB'\\a'\fP , \fB'\\b'\fP , \fB'\\f'\fP , \fB'\\r'\fP , \fB'\\t'\fP
|
|
, \fB'\\v'\fP ) shall be written as the
|
|
corresponding escape sequence; the \fB'\\n'\fP in that table is not
|
|
applicable. Non-printable characters not in the table shall
|
|
be written as one three-digit octal number (with a preceding backslash
|
|
character) for each byte in the character (most significant
|
|
byte first). If the size of a byte on the system is greater than nine
|
|
bits, the format used for non-printable characters is
|
|
implementation-defined.
|
|
.LP
|
|
Long lines shall be folded, with the point of folding indicated by
|
|
<newline> preceded by a backslash; the length at which
|
|
folding occurs is unspecified, but should be appropriate for the output
|
|
device. The end of each line shall be marked with a
|
|
\fB'$'\fP , and \fB'$'\fP characters within the text shall be written
|
|
with a preceding backslash. An \fBl\fP command can be
|
|
appended to any other command other than \fBe\fP, \fBE\fP, \fBf\fP,
|
|
\fBq\fP, \fBQ\fP, \fBr\fP, \fBw\fP, or \fB!\fP. The
|
|
current line number shall be set to the address of the last line written.
|
|
.SS Move Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)m\fP\fIaddress\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBm\fP command shall reposition the addressed lines after the
|
|
line addressed by \fIaddress\fP. Address 0 shall be valid
|
|
for \fIaddress\fP and cause the addressed lines to be moved to the
|
|
beginning of the buffer. It shall be an error if address
|
|
\fIaddress\fP falls within the range of moved lines. The current line
|
|
number shall be set to the address of the last line
|
|
moved.
|
|
.SS Number Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)n
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBn\fP command shall write to standard output the addressed lines,
|
|
preceding each line by its line number and a
|
|
<tab>; the current line number shall be set to the address of the
|
|
last line written. The \fBn\fP command can be appended to
|
|
any command other than \fBe\fP, \fBE\fP, \fBf\fP, \fBq\fP, \fBQ\fP,
|
|
\fBr\fP, \fBw\fP, or \fB!\fP.
|
|
.SS Print Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)p
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBp\fP command shall write to standard output the addressed lines;
|
|
the current line number shall be set to the address of
|
|
the last line written. The \fBp\fP command can be appended to any
|
|
command other than \fBe\fP, \fBE\fP, \fBf\fP, \fBq\fP,
|
|
\fBQ\fP, \fBr\fP, \fBw\fP, or \fB!\fP.
|
|
.SS Prompt Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBP
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBP\fP command shall cause \fIed\fP to prompt with an asterisk
|
|
( \fB'*'\fP ) (or \fIstring\fP, if \fB-p\fP is
|
|
specified) for all subsequent commands. The \fBP\fP command alternatively
|
|
shall turn this mode on and off; it shall be initially
|
|
on if the \fB-p\fP option is specified; otherwise, off. The current
|
|
line number shall be unchanged.
|
|
.SS Quit Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBq
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBq\fP command shall cause \fIed\fP to exit. If the buffer has
|
|
changed since the last time the entire buffer was written,
|
|
the user shall be warned, as described previously.
|
|
.SS Quit Without Checking Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBQ
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBQ\fP command shall cause \fIed\fP to exit without checking
|
|
whether changes have been made in the buffer since the last
|
|
\fBw\fP command.
|
|
.SS Read Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB($)r\fP \fB[\fP\fIfile\fP\fB]\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBr\fP command shall read in the file named by the pathname \fIfile\fP
|
|
and append it after the addressed line. If no
|
|
\fIfile\fP argument is given, the currently remembered pathname, if
|
|
any, shall be used (see the \fBe\fP and \fBf\fP commands).
|
|
The currently remembered pathname shall not be changed unless there
|
|
is no remembered pathname. Address 0 shall be valid for
|
|
\fBr\fP and shall cause the file to be read at the beginning of the
|
|
buffer. If the read is successful, and \fB-s\fP was not
|
|
specified, the number of bytes read shall be written to standard output
|
|
in the following format:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"%d\\n", <\fP\fInumber of bytes read\fP\fB>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
The current line number shall be set to the address of the last line
|
|
read in. If \fIfile\fP is replaced by \fB'!'\fP , the
|
|
rest of the line shall be taken to be a shell command line whose output
|
|
is to be read. Such a shell command line shall not be
|
|
remembered as the current pathname.
|
|
.SS Substitute Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)s/\fP\fIRE\fP\fB/\fP\fIreplacement\fP\fB/\fP\fIflags\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBs\fP command shall search each addressed line for an occurrence
|
|
of the specified RE and replace either the first or all
|
|
(non-overlapped) matched strings with the \fIreplacement\fP; see the
|
|
following description of the \fBg\fP suffix. It is an error
|
|
if the substitution fails on every addressed line. Any character other
|
|
than <space> or <newline> can be used instead of
|
|
a slash to delimit the RE and the replacement. Within the RE, the
|
|
RE delimiter itself can be used as a literal character if it is
|
|
preceded by a backslash. The current line shall be set to the address
|
|
of the last line on which a substitution occurred.
|
|
.LP
|
|
An ampersand ( \fB'&'\fP ) appearing in the \fIreplacement\fP shall
|
|
be replaced by the string matching the RE on the
|
|
current line. The special meaning of \fB'&'\fP in this context can
|
|
be suppressed by preceding it by backslash. As a more
|
|
general feature, the characters \fB'\\n'\fP , where \fIn\fP is a digit,
|
|
shall be replaced by the text matched by the
|
|
corresponding back-reference expression. When the character \fB'%'\fP
|
|
is the only character in the \fIreplacement\fP, the
|
|
\fIreplacement\fP used in the most recent substitute command shall
|
|
be used as the \fIreplacement\fP in the current substitute
|
|
command; if there was no previous substitute command, the use of \fB'%'\fP
|
|
in this manner shall be an error. The \fB'%'\fP
|
|
shall lose its special meaning when it is in a replacement string
|
|
of more than one character or is preceded by a backslash. For
|
|
each backslash ( \fB'\\'\fP ) encountered in scanning \fIreplacement\fP
|
|
from beginning to end, the following character shall
|
|
lose its special meaning (if any). It is unspecified what special
|
|
meaning is given to any character other than \fB'&'\fP ,
|
|
\fB'\\'\fP , \fB'%'\fP , or digits.
|
|
.LP
|
|
A line can be split by substituting a <newline> into it. The application
|
|
shall ensure it escapes the <newline> in
|
|
the \fIreplacement\fP by preceding it by backslash. Such substitution
|
|
cannot be done as part of a \fBg\fP or \fBv\fP \fIcommand
|
|
list\fP. The current line number shall be set to the address of the
|
|
last line on which a substitution is performed. If no
|
|
substitution is performed, the current line number shall be unchanged.
|
|
If a line is split, a substitution shall be considered to
|
|
have been performed on each of the new lines for the purpose of determining
|
|
the new current line number. A substitution shall be
|
|
considered to have been performed even if the replacement string is
|
|
identical to the string that it replaces.
|
|
.LP
|
|
The application shall ensure that the value of \fIflags\fP is zero
|
|
or more of:
|
|
.TP 7
|
|
\fIcount\fP
|
|
Substitute for the \fIcount\fPth occurrence only of the RE found on
|
|
each addressed line.
|
|
.TP 7
|
|
\fBg\fP
|
|
Globally substitute for all non-overlapping instances of the RE rather
|
|
than just the first one. If both \fBg\fP and
|
|
\fIcount\fP are specified, the results are unspecified.
|
|
.TP 7
|
|
\fBl\fP
|
|
Write to standard output the final line in which a substitution was
|
|
made. The line shall be written in the format specified for
|
|
the \fBl\fP command.
|
|
.TP 7
|
|
\fBn\fP
|
|
Write to standard output the final line in which a substitution was
|
|
made. The line shall be written in the format specified for
|
|
the \fBn\fP command.
|
|
.TP 7
|
|
\fBp\fP
|
|
Write to standard output the final line in which a substitution was
|
|
made. The line shall be written in the format specified for
|
|
the \fBp\fP command.
|
|
.sp
|
|
.SS Copy Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.,.)t\fP\fIaddress\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBt\fP command shall be equivalent to the \fBm\fP command, except
|
|
that a copy of the addressed lines shall be placed
|
|
after address \fIaddress\fP (which can be 0); the current line number
|
|
shall be set to the address of the last line added.
|
|
.SS Undo Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBu
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBu\fP command shall nullify the effect of the most recent command
|
|
that modified anything in the buffer, namely the most
|
|
recent \fBa\fP, \fBc\fP, \fBd\fP, \fBg\fP, \fBi\fP, \fBj\fP, \fBm\fP,
|
|
\fBr\fP, \fBs\fP, \fBt\fP, \fBu\fP, \fBv\fP,
|
|
\fBG\fP, or \fBV\fP command. All changes made to the buffer by a \fBg\fP,
|
|
\fBG\fP, \fBv\fP, or \fBV\fP global command shall
|
|
be undone as a single change; if no changes were made by the global
|
|
command (such as with \fBg\fP/RE/ \fBp\fP), the \fBu\fP
|
|
command shall have no effect. The current line number shall be set
|
|
to the value it had immediately before the command being undone
|
|
started.
|
|
.SS Global Non-Matched Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(1,$)v/\fP\fIRE\fP\fB/\fP\fIcommand list\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
This command shall be equivalent to the global command \fBg\fP except
|
|
that the lines that are marked during the first step
|
|
shall be those for which the line excluding the terminating <newline>
|
|
does not match the RE.
|
|
.SS Interactive Global Not-Matched Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(1,$)V/\fP\fIRE\fP\fB/
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
This command shall be equivalent to the interactive global command
|
|
\fBG\fP except that the lines that are marked during the
|
|
first step shall be those for which the line excluding the terminating
|
|
<newline> does not match the RE.
|
|
.SS Write Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(1,$)w\fP \fB[\fP\fIfile\fP\fB]
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The \fBw\fP command shall write the addressed lines into the file
|
|
named by the pathname \fIfile\fP. The command shall create
|
|
the file, if it does not exist, or shall replace the contents of the
|
|
existing file. The currently remembered pathname shall not be
|
|
changed unless there is no remembered pathname. If no pathname is
|
|
given, the currently remembered pathname, if any, shall be used
|
|
(see the \fBe\fP and \fBf\fP commands); the current line number shall
|
|
be unchanged. If the command is successful, the number of
|
|
bytes written shall be written to standard output, unless the \fB-s\fP
|
|
option was specified, in the following format:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"%d\\n", <\fP\fInumber of bytes written\fP\fB>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
If \fIfile\fP begins with \fB'!'\fP , the rest of the line shall be
|
|
taken to be a shell command line whose standard input
|
|
shall be the addressed lines. Such a shell command line shall not
|
|
be remembered as the current pathname. This usage of the write
|
|
command with \fB'!'\fP shall not be considered as a "last \fBw\fP
|
|
command that wrote the entire buffer", as described
|
|
previously; thus, this alone shall not prevent the warning to the
|
|
user if an attempt is made to destroy the editor buffer via the
|
|
\fBe\fP or \fBq\fP commands.
|
|
.SS Line Number Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB($)=
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The line number of the addressed line shall be written to standard
|
|
output in the following format:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"%d\\n", <\fP\fIline number\fP\fB>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
The current line number shall be unchanged by this command.
|
|
.SS Shell Escape Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB!\fP\fIcommand\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
The remainder of the line after the \fB'!'\fP shall be sent to the
|
|
command interpreter to be interpreted as a shell command
|
|
line. Within the text of that shell command line, the unescaped character
|
|
\fB'%'\fP shall be replaced with the remembered
|
|
pathname; if a \fB'!'\fP appears as the first character of the command,
|
|
it shall be replaced with the text of the previous shell
|
|
command executed via \fB'!'\fP . Thus, \fB"!!"\fP shall repeat the
|
|
previous !\fIcommand\fP. If any replacements of
|
|
\fB'%'\fP or \fB'!'\fP are performed, the modified line shall be written
|
|
to the standard output before \fIcommand\fP is
|
|
executed. The \fB!\fP command shall write:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB"!\\n"
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.LP
|
|
to standard output upon completion, unless the \fB-s\fP option is
|
|
specified. The current line number shall be unchanged.
|
|
.SS Null Command
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB(.+1)
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
An address alone on a line shall cause the addressed line to be written.
|
|
A <newline> alone shall be equivalent to
|
|
\fB"+1p"\fP . The current line number shall be set to the address
|
|
of the written line.
|
|
.SH EXIT STATUS
|
|
.LP
|
|
The following exit values shall be returned:
|
|
.TP 7
|
|
\ 0
|
|
Successful completion without any file or command errors.
|
|
.TP 7
|
|
>0
|
|
An error occurred.
|
|
.sp
|
|
.SH CONSEQUENCES OF ERRORS
|
|
.LP
|
|
When an error in the input script is encountered, or when an error
|
|
is detected that is a consequence of the data (not) present
|
|
in the file or due to an external condition such as a read or write
|
|
error:
|
|
.IP " *" 3
|
|
If the standard input is a terminal device file, all input shall be
|
|
flushed, and a new command read.
|
|
.LP
|
|
.IP " *" 3
|
|
If the standard input is a regular file, \fIed\fP shall terminate
|
|
with a non-zero exit status.
|
|
.LP
|
|
.LP
|
|
\fIThe following sections are informative.\fP
|
|
.SH APPLICATION USAGE
|
|
.LP
|
|
Because of the extremely terse nature of the default error messages,
|
|
the prudent script writer begins the \fIed\fP input
|
|
commands with an \fBH\fP command, so that if any errors do occur at
|
|
least some clue as to the cause is made available.
|
|
.LP
|
|
In previous versions, an obsolescent \fB-\fP option was described.
|
|
This is no longer specified. Applications should use the
|
|
\fB-s\fP option. Using \fB-\fP as a \fIfile\fP operand now produces
|
|
unspecified results. This allows implementations to continue
|
|
to support the former required behavior.
|
|
.SH EXAMPLES
|
|
.LP
|
|
None.
|
|
.SH RATIONALE
|
|
.LP
|
|
The initial description of this utility was adapted from the SVID.
|
|
It contains some features not found in Version 7 or
|
|
BSD-derived systems. Some of the differences between the POSIX and
|
|
BSD \fIed\fP utilities include, but need not be limited to:
|
|
.IP " *" 3
|
|
The BSD \fB-\fP option does not suppress the \fB'!'\fP prompt after
|
|
a \fB!\fP command.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the special meanings of the \fB'%'\fP and \fB'!'\fP
|
|
characters within a \fB!\fP command.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the \fIaddresses\fP \fB';'\fP and \fB','\fP .
|
|
.LP
|
|
.IP " *" 3
|
|
BSD allows the command/suffix pairs \fBpp\fP, \fBll\fP, and so on,
|
|
which are unspecified in this volume of
|
|
IEEE\ Std\ 1003.1-2001.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the \fB'!'\fP character part of the \fBe\fP,
|
|
\fBr\fP, or \fBw\fP commands.
|
|
.LP
|
|
.IP " *" 3
|
|
A failed \fBg\fP command in BSD sets the line number to the last line
|
|
searched if there are no matches.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not default the \fIcommand list\fP to the \fBp\fP command.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the \fBG\fP, \fBh\fP, \fBH\fP, \fBn\fP, or \fBV\fP
|
|
commands.
|
|
.LP
|
|
.IP " *" 3
|
|
On BSD, if there is no inserted text, the insert command changes the
|
|
current line to the referenced line -1; that is, the line
|
|
before the specified line.
|
|
.LP
|
|
.IP " *" 3
|
|
On BSD, the \fIjoin\fP command with only a single address changes
|
|
the current line to that
|
|
address.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the \fBP\fP command; moreover, in BSD it is synonymous
|
|
with the \fBp\fP command.
|
|
.LP
|
|
.IP " *" 3
|
|
BSD does not support the \fIundo\fP of the commands \fBj\fP, \fBm\fP,
|
|
\fBr\fP, \fBs\fP, or \fBt\fP.
|
|
.LP
|
|
.IP " *" 3
|
|
The Version 7 \fIed\fP command \fBW\fP, and the BSD \fIed\fP commands
|
|
\fBW\fP, \fBwq\fP, and \fBz\fP are not present in
|
|
this volume of IEEE\ Std\ 1003.1-2001.
|
|
.LP
|
|
.LP
|
|
The \fB-s\fP option was added to allow the functionality of the now
|
|
withdrawn \fB-\fP option in a manner compatible with the
|
|
Utility Syntax Guidelines.
|
|
.LP
|
|
In early proposals there was a limit, {ED_FILE_MAX}, that described
|
|
the historical limitations of some \fIed\fP utilities in
|
|
their handling of large files; some of these have had problems with
|
|
files larger than 100000 bytes. It was this limitation that
|
|
prompted much of the desire to include a \fIsplit\fP command in this
|
|
volume of
|
|
IEEE\ Std\ 1003.1-2001. Since this limit was removed, this volume
|
|
of IEEE\ Std\ 1003.1-2001 requires that
|
|
implementations document the file size limits imposed by \fIed\fP
|
|
in the conformance document. The limit {ED_LINE_MAX} was also
|
|
removed; therefore, the global limit {LINE_MAX} is used for input
|
|
and output lines.
|
|
.LP
|
|
The manner in which the \fBl\fP command writes non-printable characters
|
|
was changed to avoid the historical
|
|
backspace-overstrike method. On video display terminals, the overstrike
|
|
is ambiguous because most terminals simply replace
|
|
overstruck characters, making the \fBl\fP format not useful for its
|
|
intended purpose of unambiguously understanding the content of
|
|
the line. The historical backslash escapes were also ambiguous. (The
|
|
string \fB"a\\0011"\fP could represent a line containing
|
|
those six characters or a line containing the three characters \fB'a'\fP
|
|
, a byte with a binary value of 1, and a 1.) In the
|
|
format required here, a backslash appearing in the line is written
|
|
as \fB"\\\\"\fP so that the output is truly unambiguous. The
|
|
method of marking the ends of lines was adopted from the \fIex\fP
|
|
editor and is required for
|
|
any line ending in <space>s; the \fB'$'\fP is placed on all lines
|
|
so that a real \fB'$'\fP at the end of a line cannot
|
|
be misinterpreted.
|
|
.LP
|
|
Systems with bytes too large to fit into three octal digits must devise
|
|
other means of displaying non-printable characters.
|
|
Consideration was given to requiring that the number of octal digits
|
|
be large enough to hold a byte, but this seemed to be too
|
|
confusing for applications on the vast majority of systems where three
|
|
digits are adequate. It would be theoretically possible for
|
|
the application to use the \fIgetconf\fP utility to find out the CHAR_BIT
|
|
value and deal
|
|
with such an algorithm; however, there is really no portable way that
|
|
an application can use the octal values of the bytes across
|
|
various coded character sets, so the additional specification was
|
|
not worthwhile.
|
|
.LP
|
|
The description of how a NUL is written was removed. The NUL character
|
|
cannot be in text files, and this volume of
|
|
IEEE\ Std\ 1003.1-2001 should not dictate behavior in the case of
|
|
undefined, erroneous input.
|
|
.LP
|
|
Unlike some of the other editing utilities, the filenames accepted
|
|
by the \fBE\fP, \fBe\fP, \fBR\fP, and \fBr\fP commands
|
|
are not patterns.
|
|
.LP
|
|
Early proposals stated that the \fB-p\fP option worked only when standard
|
|
input was associated with a terminal device. This has
|
|
been changed to conform to historical implementations, thereby allowing
|
|
applications to interpose themselves between a user and the
|
|
\fIed\fP utility.
|
|
.LP
|
|
The form of the substitute command that uses the \fBn\fP suffix was
|
|
limited in some historical documentation (where this was
|
|
described incorrectly as "backreferencing"). This limit has been omitted
|
|
because there is no reason why an editor processing
|
|
lines of {LINE_MAX} length should have this restriction. The command
|
|
\fBs/x/X/2047\fP should be able to substitute the 2047th
|
|
occurrence of \fB'x'\fP on a line.
|
|
.LP
|
|
The use of printing commands with printing suffixes (such as \fBpn\fP,
|
|
\fBlp\fP, and so on) was made unspecified because
|
|
BSD-based systems allow this, whereas System V does not.
|
|
.LP
|
|
Some BSD-based systems exit immediately upon receipt of end-of-file
|
|
if all of the lines in the file have been deleted. Since
|
|
this volume of IEEE\ Std\ 1003.1-2001 refers to the \fBq\fP command
|
|
in this instance, such behavior is not allowed.
|
|
.LP
|
|
Some historical implementations returned exit status zero even if
|
|
command errors had occurred; this is not allowed by this
|
|
volume of IEEE\ Std\ 1003.1-2001.
|
|
.LP
|
|
Some historical implementations contained a bug that allowed a single
|
|
period to be entered in input mode as <backslash>
|
|
<period> <newline>. This is not allowed by \fIed\fP because there
|
|
is no description of escaping any of the characters
|
|
in input mode; backslashes are entered into the buffer exactly as
|
|
typed. The typical method of entering a single period has been to
|
|
precede it with another character and then use the substitute command
|
|
to delete that character.
|
|
.LP
|
|
It is difficult under some modes of some versions of historical operating
|
|
system terminal drivers to distinguish between an
|
|
end-of-file condition and terminal disconnect. IEEE\ Std\ 1003.1-2001
|
|
does not require implementations to distinguish
|
|
between the two situations, which permits historical implementations
|
|
of the \fIed\fP utility on historical platforms to conform.
|
|
Implementations are encouraged to distinguish between the two, if
|
|
possible, and take appropriate action on terminal disconnect.
|
|
.LP
|
|
Historically, \fIed\fP accepted a zero address for the \fBa\fP and
|
|
\fBr\fP commands in order to insert text at the start of
|
|
the edit buffer. When the buffer was empty the command \fB.=\fP returned
|
|
zero. IEEE\ Std\ 1003.1-2001 requires conformance
|
|
to historical practice.
|
|
.LP
|
|
For consistency with the \fBa\fP and \fBr\fP commands and better user
|
|
functionality, the \fBi\fP and \fBc\fP commands must
|
|
also accept an address of 0, in which case 0\fIi\fP is treated as
|
|
1\fIi\fP and likewise for the \fBc\fP command.
|
|
.LP
|
|
All of the following are valid addresses:
|
|
.TP 7
|
|
\fB+++\fP
|
|
Three lines after the current line.
|
|
.TP 7
|
|
\fB/\fP\fIpattern\fP\fB/-\fP
|
|
One line before the next occurrence of pattern.
|
|
.TP 7
|
|
\fB-2\fP
|
|
Two lines before the current line.
|
|
.TP 7
|
|
\fB3\ ----\ 2\fP
|
|
Line one (note the intermediate negative address).
|
|
.TP 7
|
|
\fB1\ 2\ 3\fP
|
|
Line six.
|
|
.sp
|
|
.LP
|
|
Any number of addresses can be provided to commands taking addresses;
|
|
for example, \fB"1,2,3,4,5p"\fP prints lines 4 and 5,
|
|
because two is the greatest valid number of addresses accepted by
|
|
the \fBprint\fP command. This, in combination with the semicolon
|
|
delimiter, permits users to create commands based on ordered patterns
|
|
in the file. For example, the command \fB"3;/foo/;+2p"\fP
|
|
will display the first line after line 3 that contains the pattern
|
|
\fIfoo\fP, plus the next two lines. Note that the address
|
|
\fB"3;"\fP must still be evaluated before being discarded, because
|
|
the search origin for the \fB"/foo/"\fP command depends on
|
|
this.
|
|
.LP
|
|
Historically, \fIed\fP disallowed address chains, as discussed above,
|
|
consisting solely of comma or semicolon separators; for
|
|
example, \fB",,,"\fP or \fB";;;"\fP were considered an error. For
|
|
consistency of address specification, this restriction is
|
|
removed. The following table lists some of the address forms now possible:
|
|
.TS C
|
|
center; l2 l2 l2 l2 l.
|
|
\fBAddress\fP \fBAddr1\fP \fBAddr2\fP \fBStatus\fP \fBComment\fP
|
|
7, 7 7 Historical \
|
|
7,5, 5 5 Historical \
|
|
7,5,9 5 9 Historical \
|
|
7,9 7 9 Historical \
|
|
7,+ 7 8 Historical \
|
|
, 1 $ Historical \
|
|
,7 1 7 Extension \
|
|
,, $ $ Extension \
|
|
,; $ $ Extension \
|
|
7; 7 7 Historical \
|
|
7;5; 5 5 Historical \
|
|
7;5;9 5 9 Historical \
|
|
7;5,9 5 9 Historical \
|
|
7;$;4 $ 4 Historical Valid, but erroneous.
|
|
7;9 7 9 Historical \
|
|
7;+ 7 8 Historical \
|
|
; . $ Historical \
|
|
;7 . 7 Extension \
|
|
;; $ $ Extension \
|
|
;, $ $ Extension \
|
|
.TE
|
|
.LP
|
|
Historically, values could be added to addresses by including them
|
|
after one or more <blank>s; for example,
|
|
\fB"3\ -\ 5p"\fP wrote the seventh line of the file, and \fB"/foo/\ 5"\fP
|
|
was the same as \fB"5\ /foo/"\fP
|
|
\&. However, only absolute values could be added; for example, \fB"5\ /foo/"\fP
|
|
was an error. IEEE\ Std\ 1003.1-2001
|
|
requires conformance to historical practice.
|
|
.LP
|
|
Historically, \fIed\fP accepted the \fB'^'\fP character as an address,
|
|
in which case it was identical to the hyphen
|
|
character. IEEE\ Std\ 1003.1-2001 does not require or prohibit this
|
|
behavior.
|
|
.SH FUTURE DIRECTIONS
|
|
.LP
|
|
None.
|
|
.SH SEE ALSO
|
|
.LP
|
|
\fIUtility Description Defaults\fP , \fIex\fP , \fIsed\fP , \fIsh\fP
|
|
, \fIvi\fP
|
|
.SH COPYRIGHT
|
|
Portions of this text are reprinted and reproduced in electronic form
|
|
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
|
|
-- Portable Operating System Interface (POSIX), The Open Group Base
|
|
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
|
|
Electrical and Electronics Engineers, Inc and The Open Group. In the
|
|
event of any discrepancy between this version and the original IEEE and
|
|
The Open Group Standard, the original IEEE and The Open Group Standard
|
|
is the referee document. The original Standard can be obtained online at
|
|
http://www.opengroup.org/unix/online.html .
|