|ED(1)||General Commands Manual||ED(1)|
edis a line-oriented text editor. It is used to create, display, modify, and otherwise manipulate text files. If invoked with a file argument, then a copy of file is read into the editor's buffer. Changes are made to this copy and not directly to file itself. Upon quitting
ed, any changes not explicitly saved with a
wcommand are lost. Editing is done in two distinct modes: command and input. When first invoked,
edis in command mode. In this mode, commands are read from the standard input and executed to manipulate the contents of the editor buffer. A typical command might look like:
c(change) is given,
edenters input mode. This is the primary means of adding text to a file. In this mode, no commands are available; instead, the standard input is written directly to the editor buffer. Lines consist of text up to and including a newline character. Input mode is terminated by entering a single period (‘
.’) on a line. All
edcommands operate on whole lines or ranges of lines; e.g., the
dcommand deletes lines; the
mcommand moves lines, and so on. It is possible to modify only a portion of a line by means of replacement, as in the example above. However, even here, the
scommand is applied to whole lines at a time. In general,
edcommands consist of zero or more line addresses, followed by a single character command and possibly additional parameters; i.e., commands have the structure:
edcommands and line addresses support basic regular expressions (BREs). See re_format(7) for more information on regular expressions. The options are as follows:
edstandard input is from a script.
!’), then it is interpreted as a shell command. In this case, what is read is the standard output of file executed via sh(1). To read a file whose name begins with a bang, prefix the name with a backslash (‘
\’). The default filename is set to file only if it is not prefixed with a bang.
edmaintains a current address which is typically supplied to commands as the default address when none is specified. When a file is first read, the current address is set to the last line of the file. In general, the current address is set to the last line affected by a command. A line address is constructed from one of the bases in the list below, optionally followed by a numeric offset. The offset may include any combination of digits, operators (e.g., ‘
-’, and ‘
^’), and whitespace. Addresses are read from left to right, and their values are computed relative to the current address. One exception to the rule that addresses represent line numbers is the address 0 (zero). This means “before the first line”, and is legal wherever it makes sense. An address range is two addresses separated either by a comma or semi-colon. The value of the first address in a range cannot exceed the value of the second. If only one address is given in a range, then the second address is set to the given address. If an n-tuple of addresses is given where n > 2, then the corresponding range is determined by the last two addresses in the n-tuple. If only one address is expected, then the last address is used. Each address in a comma-delimited range is interpreted relative to the current address. In a semi-colon-delimited range, the first address is used to set the current address, and the second address is interpreted relative to the first. The following address symbols are recognized:
k(mark) command, where lc is a lower case letter.
edcommands are single characters, though some require additional parameters. If a command's parameters extend over several lines, then each line except for the last must be terminated with a backslash (‘
\’). In general, at most one command is allowed per line. However, most commands accept a print suffix, which is any of
n(enumerate), to print the last line affected by the command.
edrecognizes the following commands. The commands are shown together with the default address or address range supplied if none is specified (in parentheses), and other possible arguments on the right.
!command below). The default filename is unchanged. Any lines in the buffer are deleted before the output of command is read. The current address is set to the last line read.
ecommand, except that unwritten changes are discarded without warning. The current address is set to the last line read.
gcommand, the current address is set to the last line affected by command-list. If no lines were matched, the current line number remains unchanged. Each command in command-list must be on a separate line, and every line except for the last must be terminated by a backslash (‘\’). Any commands are allowed, except for
V. A newline alone in command-list is equivalent to a
Gcommand, the current address is set to the last line affected by (the last) command-list. If no lines were matched, the current line number remains unchanged. The format of command-list is the same as that of the
gcommand. A newline alone acts as a null command list. A single ‘&’ repeats the last non-null command list.
edscripts begin with this command to aid in debugging.
'lc (i.e., a single quote followed by lc) in subsequent commands. The mark is not cleared until the line is deleted or otherwise modified.
edwaits until the RETURN key is pressed before displaying the next screen. The current address is set to the last line printed.
-pstring, the command prompt is by default turned off.
edunconditionally. This is similar to the
qcommand, except that unwritten changes are discarded without warning.
!command below). The default filename is unchanged. The current address is set to the last line read.
g(global) suffix is given, then every match is replaced. The n suffix, where n is a positive number, causes only the nth match to be replaced. It is an error if no substitutions are performed on any of the addressed lines. The current address is set the last line affected. re and replacement may be delimited by any character other than space and newline (see the
scommand below). If one or two of the last delimiters is omitted, then the last line affected is printed as though the print suffix
pwere specified. An unescaped ‘
&’ in replacement is replaced by the currently matched text. The character sequence \m, where m is a number in the range [1,9], is replaced by the mth backreference expression of the matched text. If replacement consists of a single ‘
%’, then replacement from the last substitution is used. Newlines may be embedded in replacement if they are escaped with a backslash (‘
scommand accepts a count suffix n, or any combination of the characters
p. If a count suffix n is given, then only the nth match is replaced. The
rsuffix causes the regular expression of the last search to be used instead of that of the last substitution. The
gsuffix toggles the global suffix of the last substitution. The
psuffix toggles the print suffix of the last substitution. The current address is set to the last line affected.
Vare treated as a single command by undo.
uis its own inverse.
!command below). The default filename and current address are unchanged.
wcommand, except that the previous contents of file are not clobbered. The current address is unchanged.
eddoes not process command for ‘\’ (backslash) escapes. However, an unescaped ‘%’ is replaced by the default filename. When the shell returns from execution, a ‘!’ is printed to the standard output. The current line is unchanged.
edattempts to write the buffer to the file ed.hup. Nothing is written to the currently remembered file, and
edprints ‘?\n’ and returns to command mode. If interrupted during text input, the text already input is written to the current buffer, as if text input had been normally terminated.
edattempts to write the buffer if the terminal hangs up
edutility exits 0 on success, and >0 if an error occurs.
edprints a ‘?’ and either returns to command mode or exits if its input is from a script. An explanation of the last error can be printed with the
h(help) command. Since the
g(global) command masks any errors from failed searches and substitutions, it can be used to perform conditional operations in scripts; e.g.,
u(undo) command occurs in a global command list, then the command list is executed only once. If diagnostics are not disabled, attempting to quit
edor edit another file before writing a modified buffer results in an error. If the command is entered a second time, it succeeds, but any changes to the buffer are lost. sed(1), sh(1), vi(1), re_format(7) B. W. Kernighan and P. J. Plauger, Software Tools in Pascal, 1981, Addison-Wesley.
edutility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification. The commands
s(to repeat the last substitution),
zas well as the address specifier ‘%’ are extensions to that specification. The IEEE Std 1003.1-2008 (“POSIX.1”) specification says the ‘^’ address specifier is neither required nor prohibited; additionally, it says behaviour for the
-option is “unspecified”. The IEEE Std 1003.1-2008 (“POSIX.1”) specification says the
lcommand should mark the ends of lines with a ‘$’ character, and that ‘$’ characters within the text should be output preceded by a backslash; this implementation does not support that.
edcommand appeared in Version 1 AT&T UNIX.
edprocesses file arguments for backslash escapes, i.e., in a filename, any characters preceded by a backslash (‘
\’) are interpreted literally. If a text (non-binary) file is not terminated by a newline character, then
edappends one on reading/writing it. In the case of a binary file,
eddoes not append a newline on reading/writing.
|November 20, 2015||OpenBSD-6.0|