Ex and edit are text editors, used for creating and modifying files of text on the UNIX computer system. Edit is a variant of ex with features designed to make it less complicated to learn and use. In terms of command syntax and effect the editors are essentially identical, and this command summary applies to both.
The summary is meant as a quick reference for users already acquainted with edit or ex. Fuller explanations of the editors are available in the documents Edit: A Tutorial (a self-teaching introduction) and the Ex Reference Manual (the comprehensive reference source for both edit and ex). Both of these writeups are available in the Computing Services Library.
In the examples included with the summary, commands and text entered by the user are printed in boldface to distinguish them from responses printed by the computer.
In order to perform its tasks the editor sets aside a temporary work space, called a buffer, separate from the user's permanent file. Before starting to work on an existing file the editor makes a copy of it in the buffer, leaving the original untouched. All editing changes are made to the buffer copy, which must then be written back to the permanent file in order to update the old version. The buffer disappears at the end of the editing session.
During an editing session there are two usual modes of operation: command mode and text input mode. (This disregards, for the moment, open and visual modes, discussed below.) In command mode, the editor issues a colon prompt (:) to show that it is ready to accept and execute a command. In text input mode, on the other hand, there is no prompt and the editor merely accepts text to be added to the buffer. Text input mode is initiated by the commands append, insert, and change, and is terminated by typing a period as the first and only character on a line.
The editor keeps track of lines of text in the buffer by numbering them consecutively starting with 1 and renumbering as lines are added or deleted. At any given time the editor is positioned at one of these lines; this position is called the current line. Generally, commands that change the contents of the buffer print the new current line at the end of their execution.
Most commands can be preceded by one or two line-number addresses which indicate the lines to be affected. If one number is given the command operates on that line only; if two, on an inclusive range of lines. Commands that can take line-number prefixes also assume default prefixes if none are given. The default assumed by each command is designed to make it convenient to use in many instances without any line-number prefix. For the most part, a command used without a prefix operates on the current line, though exceptions to this rule should be noted. The print command by itself, for instance, causes one line, the current line, to be printed at the terminal.
The summary shows the number of line addresses that can be prefixed to each command as well as the defaults assumed if they are omitted. For example, (.,.) means that up to 2 line-numbers may be given, and that if none is given the command operates on the current line. (In the address prefix notation, ``.'' stands for the current line and ``$'' stands for the last line of the buffer.) If no such notation appears, no line-number prefix may be used.
Some commands take trailing information; only the more important instances of this are mentioned in the summary.
Some characters take on special meanings when used in context searches and in patterns given to the substitute command. For edit, these are ``^'' and ``$'', meaning the beginning and end of a line, respectively. Ex has the following additional special characters:
. & * [ ] ~
To use one of the special characters as its simple graphic representation rather than with its special meaning, precede it by a backslash (\). The backslash always has a special meaning.
Begins text input mode, adding lines to the buffer after the line specified. Appending continues until ``.'' is typed alone at the beginning of a new line, followed by a carriage return. \fI0a\fR places lines at the beginning of the buffer.
:a Three lines of text are added to the buffer after the current line. . :
Deletes indicated line(s) and initiates text input mode to replace them with new text which follows. New text is terminated the same way as with append.
:5,6c Lines 5 and 6 are deleted and replaced by these three lines. . :
Places a copy of the specified lines after the line indicated by addr. The example places a copy of lines 8 through 12, inclusive, after line 25.
:8,12co 25 Last line copied is printed :
Removes lines from the buffer and prints the current line after the deletion.
:13,15d New current line is printed :
Clears the editor buffer and then copies into it the named file, which becomes the current file. This is a way of shifting to a different file without leaving the editor. The editor issues a warning message if this command is used before saving changes made to the file already in the buffer; using the form e! overrides this protective mechanism.
:e ch10 No write since last change :e! ch10 "ch10" 3 lines, 62 characters :
If followed by a name, renames the current file to name. If used without name, prints the name of the current file.
:f ch9 "ch9" [Modified] 3 lines ... :f "ch9" [Modified] 3 lines ... :
g! or v
Searches the entire buffer (unless a smaller range is specified by line-number prefixes) and executes commands on every line with an expression matching pattern. The second form, abbreviated either g! or v, executes commands on lines that do not contain the expression pattern.
Inserts new lines of text immediately before the speciffied line. Differs from append only in that text is placed before, rather than after, the indicated lne. In other words, 1i has the same effect as 0a.
:1i These lines of text will be added prior to line 1. . :
Join lines together, adjusting white space (spaces and tabs) as necessary.
:2,5j Resulting line is printed :
Prints lines in a more unambiguous way than the print command does. The end of a line, for example, is marked with a ``$'', and tabs printed as ``^I''.
:9l This is line 9$ :
Moves the specified lines to a position after the line indicated by addr.
:12,15m 25 New current line is printed :
Prints each line preceded by its buffer line number.
:nu 10 This is line 10 :
Too involved to discuss here, but if you enter open mode accidentally, press the ESC key followed by q to get back into normal editor command mode. Edit is designed to prevent accidental use of the open command.
Saves a copy of the current buffer contents as though the system had just crashed. This is for use in an emergency when a write command has failed and you don't know how else to save your work.
:preserve File preserved. :
Prints the text of line(s).
:+2,+3p The second and third lnes after the current line :
Ends the editing session. You will receive a warning if you have changed the buffer since last writing its contents to the file. In this event you must either type w to write, or type q! to exit from the editor without saving your changes.
:q No write since last change :q! %
Places a copy of file in the buffer after the specified line. Address 0 is permissible and causes the copy of file to be placed at the beginning of the buffer. The read command does not erase any text already in the buffer. If no line number is specified, file is placed after the current line.
:0r newfile "newfile" 5 lines, 86 characters :
Retrieves a copy of the editor buffer after a system crash, editor crash, phone line disconnection, or preserve command.
Replaces the first ocurrence of pattern on a line with replacement. Including a g after the command changes all occurrences of pattern on the line. The c option allows the user to confirm each substitution before it is made; see the manual for details.
:3p Line 3 contains a misstake :s/misstake/mistake/ Line 3 contains a mistake :
Reverses the changes made in the buffer by the last buffer-editing command. Note that this example contains a notification about the number of lines affected.
:1,15d 15 lines deleted new line number 1 is printed :u 15 more lines in file ... old line number 1 is printed :
Copies data from the buffer onto a permanent file. If no file is named, the current filename is used. The file is automatically created if it does not yet exist. A response containing the number of lines and characters in the file indicates that the write has been completed successfully. The editor's built-in protections against overwriting existing files will in some circumstances inhibit a write. The form w! forces the write, confirming that an existing file is to be overwritten.
:w "file7" 64 lines, 1122 characters :w file8 "file8" File exists ... :w! file8 "file8" 64 lines, 1122 characters :
Prints a screen full of text starting with the line indicated; or, if count is specified, prints that number of lines. Variants of the z command are described in the manual.
Executes the remainder of the line after ! as a UNIX command. The buffer is unchanged by this, and control is returned to the editor when the execution of command is complete.
:!date Fri Jun 9 12:15:11 PDT 1978 ! :
Prints the next scroll of text, normally half of a screen. See the manual for details of the scroll option.
An address alone followed by a carriage return causes the line to be printed. A carriage return by itself prints the line following the current line.
:<cr> the line after the current line :
Searches for the next line in which pattern occurs and prints it.
:/This pattern/ This pattern next occurs here. :
Repeats the most recent search.
:// This pattern also occurs here. :
Searches in the reverse direction for pattern.
Repeats the most recent search, moving in the reverse direction through the buffer.