ed(1) General Commands Manual ed(1)
NAME
ed, red - line-oriented text editor
SYNOPSIS
string] [file]
string] [file]
DESCRIPTION
The command executes a line-oriented text editor. It is most commonly used in scripts and noninteractive editing applications because,
even though it can be used interactively, other editors such as and are typically easier to use in an interactive environment.
If file is specified, performs an command (see below) on the named file; that is to say, the file is read into buffer so that it can be
edited.
Options
The following options are recognized:
Use string as the prompt string when in command mode. By default, there is no prompt string.
Suppress printing of byte counts by
and commands, and suppress the prompt after a command. The option is obsolescent and will be removed in a future
release.
Perform an command first to handle an encrypted file.
File Handling
operates on a copy of the file it is editing; changes made to the copy have no effect on the original file until a (write) command is
given. The copy of the text being edited resides in a temporary file called the buffer. There is only one buffer.
is a restricted version of that only allows editing of files in the current directory and prohibits executing shell commands via Attempts
to bypass these restrictions result in the error message
Both and support the fspec(4) formatting capability. After including a format specification as the first line of file and invoking with
the controlling terminal in or mode (see stty(1)), the specified tab stops are automatically used when scanning file. For example, if the
first line of a file contained
the tab stops would be set at columns 5, 10, and 15, and a maximum line length of 72 would be imposed.
When you input text, expands tab characters as they are typed to every eighth column as a default.
Editor Commands Structure
Commands to 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 is allowed on a line. Append, change, and insert commands accept text input which is then placed in the buf-
fer as appropriate. While is accepting text following an append, change, or insert command, it is said to be in input mode. While in
input mode, no editor commands are recognized; all input is merely collected. To terminate input mode, type a period alone at the begin-
ning of a line.
Regular Expressions
supports the Basic Regular Expression (RE) syntax (see regexp(5)), with the following additions:
o The null RE (for example, is equivalent to the last RE encountered.
o If the closing delimiter of an RE or of a replacement string (for example, would be the last character before a newline, that
delimiter can be omitted, in which case the addressed line is printed. The following pairs of commands are equivalent:
s/s1/s2 g/s1 ?s1
s/s1/s2/p g/s1/p ?s1?
Line Addresses
To understand line addressing, remember that maintains a pointer to the current line. Generally speaking, the current line is the last
line affected by a command. The exact effect of a given command on the current line is discussed under the description of each command.
Addresses are interpreted according to the following rules:
1. The character refers to the current line.
2. The character refers to the last line of the buffer.
3. A decimal number n refers to the nth line of the buffer.
4. A refers to the line marked with the mark name character x, which must be a lower-case letter. Lines are marked with the com-
mand described below.
5. An RE enclosed by slashes () refers to 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 RE. 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. (Also
see below.)
6. An RE enclosed by 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 RE. If necessary, the
search wraps around to the end of the buffer and continues up to and including the current line. (Also see below.)
7. An address followed by a plus or minus sign followed by a decimal number specifies that address plus or minus the indicated num-
ber of lines. The plus sign can be omitted.
8. If an address begins with or the addition or subtraction is calculated with respect to the current line. For example, is inter-
preted as
9. If an address ends with or 1 is added to or subtracted from the address, respectively. As a consequence of this and rule 8
above, the address refers to the line preceding the current line. (To maintain compatibility with earlier versions of the edi-
tor, the circumflex and characters are interpreted identically when encountered in addresses.) Moreover, multiple trailing and
characters have a cumulative effect, so refers to the second line preceding the current line.
10. For convenience, a comma represents the address pair while a semicolon represents the pair Additionally, represents the address
pair while represents the pair
Commands require zero, one, or two addresses. Commands that do not use addresses treat the presence of an address as an error. Commands
that accept one or two addresses assume default addresses when the number of addresses specified is insufficient. If more addresses are
specified than a given command requires, the last one or two are used as appropriate.
Addresses are usually separated from each other by a comma They can also be separated by a semicolon in which case the current line is set
to the first address, after which 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.
Editor Commands
In the following list of commands, the default addresses are shown in parentheses (parentheses are not part of the address and should not
be placed in an actual command except for other purposes).
It is generally illegal for more than one command to appear on a line. However, any command (except or can be suffixed by or in which case
the current line is respectively either listed, numbered, or printed, as discussed below under the and commands.
text
The (append) command reads text and appends it after the addressed line. Upon completion, the new current line is the last
inserted line, or, if no text was added, at the addressed line. Address 0 is legal for this command, causing the appended
text to be placed at the beginning of the buffer.
text
The (change) command deletes the addressed lines then accepts input text to replace the deleted lines. Upon completion, the new
current line is the last line in text or, if no text was provided, at the first line after the deleted line or lines.
Address 0 would be interpreted as address 1.
The (delete) command deletes the addressed lines from the buffer. Upon completion, the new current line is the first line fol-
lowing the deleted text, or the last line in the file if the deleted line or lines were at the end of the buffer.
The (edit) command deletes the entire contents of the buffer, then reads in the named file. Upon completion, the new current
line is the last line in the buffer. If no file name is given, the remembered file name, if any, is used (see the command).
The number of characters read is displayed, and file is remembered for possible use as a default file name in subsequent or
commands.
If the file name starts with the rest of the line is interpreted as a shell command whose standard output is to be read.
Such a shell command is not remembered as the current file name.
Also see below.
The (forced edit) command is identical to except that no check is made to ensure that the current buffer has not been altered
since the last command.
If file is specified, the (file name) command changes the remembered file name to file. Otherwise, it prints the remembered
file name.
The (global) command first marks every line that matches the given RE. 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 multiple-line list except the last line must end with a backslash and
commands and associated input are permitted. The that normally terminates input mode can be omitted if it would be the last
line of the command-list. An empty command-list is equivalent to the command. The and commands are not permitted in the
command-list. (Also see below.)
The interactive
(Global) command first marks every line that matches the given RE. Then, for every such line, the line is printed, then the
current line is changed to that line and one command (other than or can be input and executed. After executing that com-
mand, the next marked line is printed, and so on. A newline character acts as a null command, and an causes the re-execu-
tion of the most recent command executed within the current invocation of Note that the commands input as part of the execu-
tion of the command may address and affect any lines in the buffer. The command can be terminated by an interrupt signal
(ASCII DEL or BREAK).
The (help) command gives a short error message explaining the reason for the most recent diagnostic.
The (Help) command causes to enter a mode in which error messages are printed for all subsequent diagnostics. It also explains
the previous if there was one. The command alternately turns this mode on and off. Initially, it is off.
text
The (insert) command inserts the given text before the addressed line. Upon completion, the current line is the last inserted
line, or, if there were none, the addressed line. This command differs from the command only in the placement of the input
text. Address 0 is not legal for this command.
Under the UNIX 2003 environment (see standards(5)), the (insert) command interprets address 0 as address 1.
The (join) command joins contiguous lines by removing the appropriate newline characters. If exactly one address is given, this
command does nothing.
The (mark) command marks the addressed line with the name x, which must be a lower-case letter. The address then addresses this
line. Upon completion, the new current line remains unchanged from before.
The (list) command writes the addressed lines to standard output in a visually unambiguous form. Characters listed in the fol-
lowing table are written as the corresponding escape sequence. Nonprintable characters not in the table are written as a
three-digit octal number (with a preceding backslash character) for each byte in the character (most significant byte
first).
Long lines are folded with the point of folding indicated by writing a backslash character followed by a newline. The end
of each line is marked with a An (ell) command can be appended to any command other than or The current line number is set
to the address of the last line written.
|
Escape ASCII | Escape ASCII
Sequence Represents Name | Sequence Represents Name
\ backslash |
carriage return CR
a alert BEL | horizontal tab HT
backspace BS | v vertical tab VT
f formfeed FF |
The (move) command repositions the addressed lines after the line addressed by a. Address 0 is legal for a, causing the
addressed lines to be moved to the beginning of the file. It is an error if address a falls within the range of moved
lines; Upon completion, the new current line is the last line moved.
The (number) command prints the addressed lines, preceding each line by its line number and a tab character. Upon completion,
the new current line is the last line printed. The command can be appended to any command other than or
The (print) command prints the addressed lines. Upon completion, the new current line is the last line printed. The command
may be appended to any other command other than or For example, deletes the current line and prints the new current line.
The (prompt) command causes to prompt with an asterisk (or with string if the option was specified in the command line) for all
subsequent commands. The command alternately turns this mode on and off. It is initially on if the option was specified;
otherwise, off. The current line number is unchanged.
The (quit) command causes to exit. No automatic write of a file is done (but see below).
The editor exits unconditionally without checking
for changes in the buffer since the last command.
The (read) command reads the specified file into the buffer after the addressed line. If no file name is given, the remembered
file name, if any, is used (see the and commands). The remembered file name is not changed unless file is the very first
file name mentioned since was invoked. Address 0 is legal for and places the contents of file at the beginning of the buf-
fer. If the read is successful, the number of characters read is displayed. Upon completion, the new current line is the
last line read into the buffer. If the file name starts with the rest of the line is interpreted as a shell command whose
standard output is to be read. For example, appends a listing of files in the current directory to the end of the file
being edited. A shell command is not remembered as the current file name.
The (substitute) command searches each addressed line for an occurrence of the specified RE. In each line in which a match is
found, all (nonoverlapped) matched strings are replaced by replacement if the global replacement indicator 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 nth occurrence of the matched string on each addressed line is replaced. It is an
error for the substitution to fail on all addressed lines. Any character other than space or newline can be used instead of
to delimit the RE and replacement. Upon completion, the new current line is the last line on which a substitution occurred.
(Also see below.)
If an ampersand appears in replacement, it is replaced by the string matching the RE on the current line. The special mean-
ing of in this context can be suppressed by preceding it with
As a more general feature, the characters where n is a digit, are replaced by the text matched by the nth regular subexpres-
sion of the specified RE 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 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 con-
taining more than one character or when preceded by a
A line can be split by substituting a newline character into it. The newline in replacement must be escaped by preceding it
by Such substitution cannot be done as part of a or command list.
The value of flags is zero or more of:
n Substitute for the nth occurrence only of the RE found on each addressed line.
Substitute for all nonoverlapped occurrences of the RE
on each addressed line.
Write to standard output the final line
in which a substitution was made. The line is written in the format specified for the command.
Write to standard output the final line
in which a substitution was made. The line is written in the format specified for the command.
Write to standard output the final line
in which a substitution was made. The line is written in the format specified for the command.
Same as command, except that a copy of the addressed lines is placed after address a (which can be 0). Upon completion, the new
current line is the last line of the copy.
The (undo) command nullifies the effect of the most recent command that modified anything in the buffer, that is, the most
recent or command. All changes made to the buffer by a or global command are "undone" as a single change; if no changes
were made by the global command (such as with ), the command has no effect. The current line number is set to the value it
had immediately before the command started.
The complement of the global command
in that the lines marked during the first step are those that do match the RE.
The complement of the interactive global command
in that the lines marked during the first step are those that do match the RE.
The (write) command writes the addressed lines into the named file. If the file does not exist, it is created with mode 666
(readable and writable by everyone), unless the current setting dictates otherwise (see umask(1). The remembered file name
is not changed unless file is the very first file name encountered since was invoked. If no file name is given, the remem-
bered file name, if any, is used (see the and commands). Upon completion, the current line address is unchanged. If the
command is successful, the number of characters written is displayed.
If the file name starts with the rest of the line is interpreted as a shell command whose standard input is the addressed
lines. Such a shell command is not remembered as the current file name.
A key string is demanded from the standard input.
Subsequent and commands will encrypt and decrypt the text with this key, using the algorithm of crypt(1). An explicitly
empty key turns off encryption.
The line number of the addressed line is displayed.
The current line address is unchanged by this command.
The remainder of the line after the
is sent to the shell to be interpreted and executed as a command. 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, repeats the last shell command. If any expansion is performed, the expanded
line is echoed. Upon completion, the current line address is unchanged.
An address alone on a line causes the addressed line to be printed.
A newline alone is equivalent to This technique is useful for stepping forward through the buffer.
If an interrupt signal (ASCII DEL or BREAK) is sent, prints a and returns to its command level.
The following size limitations apply: 256 characters per global command list, 64 characters per file name, and 32 MB characters in the buf-
fer. The limit on the number of lines depends on the amount of user memory: each line takes 1 word.
EXTERNAL INFLUENCES
For information about the UNIX standard environment, see standards(5).
Environment Variables
determines the preferred command-line interpreter for use in all commands. If this variable is null or not set, the POSIX shell, is used
(see sh-posix(1)).
When set, specifies a directory to be used for temporary files, overriding the default directory,
provides a default value for internationalization variables that are unset or null. If is unset or null, the default value is "C" (see
lang(5)). If any internationalization variable contains an invalid setting, all internationalization variables default to "C". See envi-
ron(5).
If is set to a nonempty string value, it overrides the values of all the other internationalization variables, including
determines the interpretation of text as single- and/or multibyte characters, the classification of characters as printable, and the char-
acters matched by character class expressions in regular expressions.
determines the locale that should be used to affect the format and contents of diagnostic messages written to standard error and informa-
tive messages written to standard output.
determines the location of message catalogues for the processing of
International Code Set Support
Single- and multibyte character code sets are supported.
DIAGNOSTICS
Command error.
Use or to get a detailed explanation.
Inaccessible file.
Use or to get a detailed explanation.
If changes have been made in the buffer since the last command that wrote the entire buffer, warns you if you attempt to destroy the buffer
with an or command. displays or then continues normal editing unless you enter a second or command, in which case the second command is
executed. The or command-line option inhibits this feature.
EXAMPLES
Make a simple substitution in from a shell script, changing the first occurrence of in any line to and save the changes in
Note that, if a command fails, the editor exits immediately.
WARNINGS
allows a of characters. Attempting to create lines longer than the allowable limit causes to produce a error message.
If a file contains lines longer than the specified limit (eg., 4096 characters), the longer lines will be truncated to the stated maximum
length. Saving the file will write the truncated version over the original file, thus overwriting the original lines completely.
A command cannot be subject to a or a command.
The command and the escape from the and commands cannot be used if the the editor is invoked from a restricted shell (see sh(1)).
The sequence in a regular expression does not match a newline character.
The command does not handle DEL correctly.
Files encrypted directly with the command with the null key cannot be edited (see crypt(1)).
If the editor input is coming from a command file (e.g., the editor exits at the first failure of a command in the command file.
When reading a file, discards ASCII NUL characters and all characters after the last newline. This can cause unexpected behavior when
using regular expressions to search for character sequences containing NUL characters or text near end-of-file.
AUTHOR
was developed by HP and OSF.
FILES
Temporary buffer file where
p is the process number.
Work is saved here if the terminal is hung up.
SEE ALSO
awk(1), csh(1), crypt(1), ex(1), grep(1), ksh(1), sed(1), sh(1), sh-posix(1), stty(1), vi(1), fspec(4), environ(5), lang(5), regexp(5),
standards(5).
The section in
STANDARDS CONFORMANCE
ed(1)