ed(1)

ed, red -- text editor

Synopsis

ed [-s] [-p string] [-x] [-C] [file]

red [-s] [-p string] [-x] [-C] [file]

Description

ed is the standard text editor. If the file argument is given, ed simulates an e command (see below) on the named file; that is to say, the file is read into ed's buffer so that it can be edited. Both ed and red process supplementary code set characters in file, and recognize supplementary code set characters in the prompt string given to the -p option (see below) according to the locale specified in the LC_CTYPE environment variable (see LANG on environ(5)). In regular expressions, pattern searches are performed on characters, not bytes, as described below.

-s: Suppresses the printing of byte counts by e, E, r, and w commands, of diagnostics from e and q commands, and of the ! prompt after a !shell command.
-p: Allows the user to specify a prompt string. The string may contain supplementary code set characters.
-x: Encryption option; when used, ed simulates an X command and prompts the user for a key. This key is used to encrypt and decrypt text using the algorithm of crypt(1). The X command makes an educated guess to determine whether text read in is encrypted or not. The temporary buffer file is encrypted also, using a transformed version of the key typed in for the -x option. See crypt(1). Also, see the ``Notices'' section at the end of this manual page.
-C: Encryption option; the same as the -x option, except that ed simulates a C command. The C command is like the X command, except that all text read in is assumed to have been encrypted.

ed operates on a copy of the file it is editing; changes made to the copy have no effect on the file until a w (write) command is given. The copy of the text being edited resides in a temporary file called the buffer. There is only one buffer.

red is a restricted version of ed. It will only allow editing of files in the current directory. It prohibits executing shell commands via !shell command. Attempts to bypass these restrictions result in an error message (restricted shell).

Both ed and red support the fspec formatting capability. After including a format specification as the first line of file and invoking ed with your terminal in stty -tabs or stty tab3 mode the specified tab stops will automatically be used when scanning file. For example, if the first line of a file contained:

   <:t5,10,15 s72:>

tab stops would be set at columns 5, 10, and 15, and a maximum line length of 72 would be imposed. NOTE: when you are entering text into the file, this format is not in effect; instead, because of being in stty -tabs or stty tab3 mode, tabs are expanded to every eighth column.

Commands to ed have a simple and regular structure: zero, one, or two addresses followed by a single-character command, possibly followed by parameters to that command. These addresses specify one or more lines in the buffer. Every command that requires addresses has default addresses, so that the addresses can very often be omitted.

In general, only one command may appear on a line. Certain commands allow the input of text. This text is placed in the appropriate place in the buffer. While ed is accepting text, it is said to be in input mode. In this mode, no commands are recognized; all input is merely collected. Leave input mode by typing a period (.) at the beginning of a line, followed immediately by pressing <Return>.

ed supports a limited form of regular expression notation; regular expressions are used in addresses to specify lines and in some commands (for example, ``s'') to specify portions of a line that are to be substituted. A regular expression specifies a set of character strings. A member of this set of strings is said to be matched by the regular expression. [See grep(1) for complete regular expression information.]

To understand addressing in ed it is necessary to know that at any time there is a current line. Generally speaking, the current line is the last line affected by a command; the exact effect on the current line is discussed under the description of each command. Addresses are constructed as follows:

The character ``.'' addresses the current line.
The character ``$'' addresses the last line of the buffer.
A decimal number n addresses the n-th line of the buffer.
'x addresses the line marked with the mark name character x, which must be a lower-case letter (a-z). Lines are marked with the k command described below.
A regular expression enclosed by slashes (``/'') addresses the first line found by searching forward from the line following the current line toward the end of the buffer and stopping at the first line containing a string matching the regular expression. If necessary, the search wraps around to the beginning of the buffer and continues up to and including the current line, so that the entire buffer is searched. See also the last paragraph of the DESCRIPTION section below.
A regular expression enclosed in question marks (?) addresses the first line found by searching backward from the line preceding the current line toward the beginning of the buffer and stopping at the first line containing a string matching the regular expression. If necessary, the search wraps around to the end of the buffer and continues up to and including the current line. See also the last paragraph of the DESCRIPTION section below.
An address followed by a plus sign (+) or a minus sign (-) followed by a decimal number specifies that address plus (respectively minus) the indicated number of lines. A shorthand for .+5 is .5.
If an address begins with ``+'' or ``-'', the addition or subtraction is taken with respect to the current line; for example, -5 is understood to mean .-5.
If an address ends with ``+'' or ``-'', then 1 is added to or subtracted from the address, respectively. As a consequence of this rule and of Rule 8, immediately above, the address - refers to the line preceding the current line. (To maintain compatibility with earlier versions of the editor, the character ^ in addresses is entirely equivalent to -.) Moreover, trailing ``+''and ``-'' characters have a cumulative effect, so -- refers to the current line less 2.
For convenience, a comma (,) stands for the address pair 1,$, while a semicolon (;) stands for the pair .,$.

Commands may require zero, one, or two addresses. Commands that require no addresses regard the presence of an address as an error. Commands that accept one or two addresses assume default addresses when an insufficient number of addresses is given; if more addresses are given than such a command requires, the last one(s) are used.

Typically, addresses are separated from each other by a comma (,). They may also be separated by a semicolon (;). In the latter case, the first address is calculated, the current line (.) is set to that value, and then the second address is calculated. This feature can be used to determine the starting line for forward and backward searches (see Rules 5 and 6, above). The second address of any two-address sequence must correspond to a line in the buffer that follows the line corresponding to the first address.

In the following list of ed commands, the parentheses shown prior to the command are not part of the address; rather they show the default address(es) for the command.

The file arguments of the e, E, f, r, w, and W commands are subject to pattern matching as in sh(1), They should be separated from the command letter by one or more spaces or tabs.

It is generally illegal for more than one command to appear on a line. However, any command (except e, f, r, or w) may be suffixed by l, n, or p in which case the current line is either listed, numbered or printed, respectively, as discussed below under the l, n, and p commands.

(.)a text .: The append command accepts zero or more lines of text and appends it after the addressed line in the buffer. The current line (.) is left at the last inserted line, or, if there were none, at the addressed line. Address 0 is legal for this command: it causes the appended text to be placed at the beginning of the buffer. The maximum number of bytes that may be entered from a terminal is LINE_MAX per line (including the new-line character). LINE_MAX is defined in limits.h.
(.)c text .: The change command deletes the addressed lines from the buffer, then accepts zero or more lines of text that replaces these lines in the buffer. The current line (.) is left at the last line input, or, if there were none, at the first line that was not deleted.
C: Same as the X command, described later, except that ed assumes all text read in for the e and r commands is encrypted unless a null key is typed in.
(.,.)d: The delete command deletes the addressed lines from the buffer. The line after the last line deleted becomes the current line; if the lines deleted were originally at the end of the buffer, the new last line becomes the current line.
e file: The edit command deletes the entire contents of the buffer and then reads the contents of file into the buffer. The current line (.) is set to the last line of the buffer. If file is not given, the currently remembered file name, if any, is used (see the f command). The number of characters read in is printed; file is remembered for possible use as a default file name in subsequent e, r, and w commands. If file is replaced by ``!'', the rest of the line is taken to be a shell (sh(1)) command whose output is to be read in. Such a shell command is not remembered as the current file name. See also ``Diagnostics'' below.
E file: The Edit command is like e, except that the editor does not check to see if any changes have been made to the buffer since the last w command.
f file: If file is given, the file-name command changes the currently remembered file name to file; otherwise, it prints the currently remembered file name.
(1,$)g/regular expression/command list: In the global command, the first step is to mark every line that matches the given regular expression. Then, for every such line, the given command list is executed with the current line (.) initially set to that line. A single command or the first of a list of commands appears on the same line as the global command. All lines of a multi-line list except the last line must be ended with a ``\''; a, i, and c commands and associated input are permitted. The . terminating input mode may be omitted if it would be the last line of the command list. An empty command list is equivalent to the p command. The C, G, v, and V commands are not permitted in the command list. See the ``Notices'' section and the last paragraph of the ``Description'' section below.
(1,$)G/regular expression/: In the interactive Global command, the first step is to mark every line that matches the given regular expression. Then, for every such line, that line is printed, the current line (.) is changed to that line, and any one command (other than one of the a, c, i, g, G, v, and V commands) may be input and is executed. After the execution of that command, the next marked line is printed, and so on; a new-line acts as a null command; an ``&'' causes the re-execution of the most recent command executed within the current invocation of G. Note that the commands input as part of the execution of the G command may address and affect any lines in the buffer. The G command can be terminated by an interrupt signal (ASCII <Del> or BREAK).
h: The help command gives a short error message that explains the reason for the most recent ? diagnostic.
H: The Help command causes ed to enter a mode in which error messages are printed for all subsequent ? diagnostics. It will also explain the previous ? if there was one. The H command alternately turns this mode on and off; it is initially off.
(.)i text .: The insert command accepts zero or more lines of text and inserts it before the addressed line in the buffer. The current line (.) is left at the last inserted line, or, if there were none, at the addressed line. This command differs from the a command only in the placement of the input text. Address 0 is not legal for this command. The maximum number of characters that may be entered from a terminal is LINE_MAX per line (including the new-line character). LINE_MAX is defined in limits.h.

(.,.+1)j

The join command joins contiguous lines by removing the appropriate new-line characters. If exactly one address is given, this command does nothing.

(.)kx

The mark command marks the addressed line with name x, which must be a lower-case letter (a-z). The address 'x then addresses this line; the current line (.) is unchanged.

(.,.)l

The list command prints the addressed lines in an unambiguous way: a few non-printing characters (for example, tab, backspace) are represented by visually mnemonic overstrikes. All other non-printing characters are printed in octal, long lines are folded and the end of each line is marked with a ``$''. An l command may be appended to any command other than e, f, r, or w.

(.,.)ma

The move command repositions the addressed line(s) after the line addressed by a. Address 0 is legal for a and causes the addressed line(s) to be moved to the beginning of the file. It is an error if address a falls within the range of moved lines; the current line (.) is left at the last line moved.

(.,.)n

The number command prints the addressed lines, preceding each line by its line number and a tab character; the current line (.) is left at the last line printed. The n command may be appended to any command other than e, f, r, or w.

(.,.)p

The print command prints the addressed lines; the current line (.) is left at the last line printed. The p command may be appended to any command other than e, f, r, or w. For example, dp deletes the current line and prints the new current line.

P

The editor will prompt with a * for all subsequent commands. The P command alternately turns this mode on and off; it is initially off.

q

The quit command causes ed to exit. No automatic write of a file is done; however, see ``Diagnostics'' below.

Q

The editor exits without checking if changes have been made in the buffer since the last w command.

($)r file

The read command reads the contents of file into the buffer. If file is not given, the currently remembered file name, if any, is used (see the e and f commands). The currently remembered file name is not changed unless file is the very first file name mentioned since ed was invoked. Address 0 is legal for r and causes the file to be read in at the beginning of the buffer. If the read is successful, the number of characters read in is printed; the current line (.) is set to the last line read in. If file is replaced by ``!'', the rest of the line is taken to be a shell (see sh(1)) command whose output is to be read in.

For example, $r !ls appends current directory to the end of the file being edited. Such a shell command is not remembered as the current file name.

(.,.)s/regular expression/replacement/ or

(.,.)s/regular expression/replacement/g or

(.,.)s/regular expression/replacement/n n = 1-512

The substitute command searches each addressed line for an occurrence of the specified regular expression. In each line in which a match is found, all (non-overlapped) matched strings are replaced by the replacement if the global replacement indicator g appears after the command. If the global indicator does not appear, only the first occurrence of the matched string is replaced. If a number n, appears after the command, only the n-th occurrence of the matched string on each addressed line is replaced. It is an error if the substitution fails on all addressed lines. Any character other than space or new-line may be used instead of ``/'' to delimit the regular expression and the replacement; the current line (.) is left at the last line on which a substitution occurred. See also the last paragraph of the ``Description'' section below.

An ampersand (&) appearing in the replacement is replaced by the string matching the regular expression on the current line. The special meaning of ``&'' in this context may be suppressed by preceding it by ``\''. As a more general feature, the characters \n, where n is a digit, are replaced by the text matched by the nth regular subexpression of the specified regular expression enclosed between ``$'' and ``$''. When nested parenthesized subexpressions are present, n is determined by counting occurrences of ``\('' starting from the left. When the character ``%'' is the only character in the replacement, the replacement used in the most recent substitute command is used as the replacement in the current substitute command. The ``%'' loses its special meaning when it is in a replacement string of more than one character or is preceded by a ``\''.

A line may be split by substituting a new-line character into it. The new-line in the replacement must be escaped by preceding it by ``\''. Such substitution cannot be done as part of a g or v command list.

(.,.)ta

This command acts just like the m command, except that a copy of the addressed lines is placed after address a (which may be 0); the current line (.) is left at the last line copied.

u

The undo command nullifies the effect of the most recent command that modified anything in the buffer, namely the most recent a, c, d, g, i, j, m, r, s, t, v, G, or V command.

(1,$)v/regular expression/command list

This command is the same as the global command g, except that the lines marked during the first step are those that do not match the regular expression.

(1,$)V/regular expression/

This command is the same as the interactive global command G, except that the lines that are marked during the first step are those that do not match the regular expression.

(1,$)w file

The write command writes the addressed lines into file. If file does not exist, it is created with mode 666 (readable and writable by everyone), unless your file creation mask dictates otherwise; see the description of the umask special command on sh(1). The currently remembered file name is not changed unless file is the very first file name mentioned since ed was invoked. If no file name is given, the currently remembered file name, if any, is used (see the e and f commands); the current line (.) is unchanged. If the command is successful, the number of characters written is printed. If file is replaced by ``!'', the rest of the line is taken to be a shell command whose standard input is the addressed lines. Such a shell command is not remembered as the current file name.

(1,$)W file

This command is the same as the write command above, except that it appends the addressed lines to the end of file if it exists. If file does not exist, it is created as described above for the w command.

X

A key is prompted for, and it is used in subsequent e, r, and w commands to decrypt and encrypt text using the crypt(1) algorithm. An educated guess is made to determine whether text read in for the e and r commands is encrypted. A null key turns off encryption. Subsequent e, r, and w commands will use this key to encrypt or decrypt the text (see crypt(1)). An explicitly empty key turns off encryption. Also, see the -x option of ed.

($)=

The line number of the addressed line is typed; the current line (.) is unchanged by this command.

!shell command

The remainder of the line after the ``!'' is sent to the UNIX system shell to be interpreted as a command. See sh(1). Within the text of that command, the unescaped character ``%'' is replaced with the remembered file name; if a ``!'' appears as the first character of the shell command, it is replaced with the text of the previous shell command. Thus, ``!!'' will repeat the last shell command. If any expansion is performed, the expanded line is echoed; the current line (.) is unchanged.

(.+1)new-line

An address alone on a line causes the addressed line to be printed. A new-line alone is equivalent to .+1p; it is useful for stepping forward through the buffer.

If an interrupt signal (ASCII <Del> or BREAK) is sent, ed prints a ``?'' and returns to its command level.

Some size limitations: LINE_MAX bytes in a line, 256 bytes in a global command list, and PATH_MAX bytes in the pathname of a file (counting slashes). LINE_MAX and PATH_MAX are defined in limits.h. The limit on the number of lines depends on the amount of user memory: each line takes 1 word.

When reading a file, ed discards ASCII NUL characters.

If a file is not terminated by a new-line character, ed adds one and puts out a message explaining what it did.

If the closing delimiter of a regular expression or of a replacement string (for example, ``/'') would be the last character before a new-line, that delimiter may be omitted, in which case the addressed line is printed. The following pairs of commands are equivalent:

s/s1/s2: s/s1/s2/p "g/s1" g/s1/p "?s1" ?s1?

Errors

?: for command errors.
?file: for an inaccessible file.
(Use the help and Help commands for detailed explanations).

If changes have been made in the buffer since the last w command that wrote the entire buffer, ed warns the user if an attempt is made to destroy ed's buffer via the e or q commands. It prints ? and allows one to continue editing. A second e or q command at this point will take effect. The -s command-line option inhibits this feature.

Files

TMPDIR: if this environment variable is not null, its value is used in place of /var/tmp as the directory name for the temporary work file.
/var/tmp: if /var/tmp exists, it is used as the directory name for the temporary work file.
/tmp: if the environment variable TMPDIR does not exist or is null, and if /var/tmp does not exist, then /tmp is used as the directory name for the temporary work file.
ed.hup: work is saved here if the terminal is hung up.
/usr/lib/locale/locale/LC_MESSAGES/uxcore.abi: language-specific message file (see LANG on environ(5)).

References

edit(1), ex(1), fspec(4), grep(1), regexp(5), sed(1), sh(1), stty(1), umask(1), vi(1)

Notices

The - option, although it continues to be supported, has been replaced in the documentation by the -s option that follows the Command Syntax Standard (see intro).

The encryption options and commands are provided with the Encryption Utilities package, which is available only in the United States.

A ! command cannot be subject to a g or a v command.

The ! command and the ! escape from the e, r, and w commands cannot be used if the editor is invoked from a restricted shell (see sh(1)).

The sequence \n in a regular expression does not match a new-line character.

If the editor input is coming from a command file (for example, ed file < ed_cmd_file), the editor exits at the first failure.

The following environment variables affect the execution of ed: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, LC_TIME, TZ (see LANG on environ(5)).