Content-type: text/html
Man page of EM
EM
Section: User Commands (1)
Updated: 4/2/76
Index
Return to Main Contents
NAME
em - editor for mortals
SYNOPSIS
em [-epqs] [file]
DESCRIPTION
Em
is a QMC variant of the standard Unix text editor - ed. It includes
all of ed, so the documentation for ed is fully applicable to em. Em
also has a number of new commands and facilities designed to improve
its interaction and increase its usefulness to users at fast vdu
terminals (such as the ITT's at QMC).
Em
differs from ed in that it normally prefixes command lines with a '>'.
For those who prefer silence, if the editor is invoked by any name not
having 'm' as its last character, no prompts will appear. Other ways
of controlling prompts are described below.
Commands to em may be typed in upper- or lower-case letters.
Em
has the following extra commands. They are designed principally for
use at any Teletype-compatible terminal operating at speeds of 1200
baud or more.
- b
-
- b-
-
The 'break' command 'b' turns on automatic line breaks. During
subsequent input to the 'open' command (see below), the first space
after character position 60 of each line typed will be replaced by
a 'newline'. Automatic line breaks are inserted only during input
with one of the variants of the 'o' command. They may be suppressed
by the command 'b-'. If the current saved filename ends in '.n'
or '.r', then 'b' is automatically invoked.
- h
-
The 'help' command displays a summary of the commands available in em.
The summary resides in /usr/share/em/emhelp, and is designed to fill
exactly 18 lines of 80 characters.
- o
-
- o/regular expression/
-
- o+
-
- o-
-
- o\
-
The 'open' command provides an additional level of editing for
interactive corrections during input of new lines of text and for
alterations to existing lines. The first two forms of the 'o' command
operate on an existing line. The line is opened with the cursor
positioned at the first occurence of the regular expression if
present, otherwise at the start of the line.
The commands 'o+', 'o-' and 'o\' are equivalent to the 'a', 'i'
and 'c' commands respectively, except in their use of the control keys
listed below, and in that they are not terminated by a line containing
a single '.', but by an ESCAPE or ^D. 'o;' is equivalent to 'o+'. In
all variants of the 'o' command it is possible to position the cursor
within the line, to delete characters, words or portions of the line,
and to insert new text at any point, using control keys as follows:
- ^A
-
re-display curent line to cursor
- ^B
-
move cursor back one word
- ESCAPE or ^D
-
exit from 'o' mode
- ^E
-
display all of current line
- ^F
-
delete forwards to end of current line
- ^H
-
gives summary of control keys
- ^Q
-
display next character
- ^R
-
Release margin
- ^S
-
re-scan from start of current line
- ^V
-
verify spelling of preceding alphabetic string (see "spell(I)")
- ^W
-
display next word
- ^Z
-
delete preceding word
- #
-
delete preceding character
- @
-
delete backwards to start of current line
- RUBOUT
-
exit with current line unchanged
Other characters (including RETURN) are inserted as typed. In this
mode, diagnostic information is provided on ITT terminals in the form
of a % when control keys are used inappropriately. When the automatic
line break facility is operative, a 'bell' is transmitted to the
terminal before each newline is inserted. The newline may be inhibited
by the '^R' code.
- x/regular expression/replacement/
-
The exchange command performs exactly the same functions as an
equivalent substitute command 's', except that it enables the user to
determine interactively whether or not each replacement is to be
performed. Each instance of the specified regular expression is
displayed, underscored with '^' characters. The user must type '.'
RETURN to perform the replacement or just RETURN to omit it.
-
-
The " command is equivalent to '.+1,.+17p'.
- %
-
The % command is equivalent to '.-7,.+7p', except that the value
of '.' is unchanged by it, and the current line is separated from its
neighbours on the screen by a line of '-'s.
- &
-
This is equivalent to '.-16,.p'.
- !
-
Two additional facilities are available under the '!' (escape to UNIX)
command. '!!'repeats the last command executed in ! mode. '%'
anywhere in a '!' line is replaced by the currently selected filename.
- >
-
- <
-
'>' turns prompting off, '<' turns it on again.
When using 'x' or 's' in em it is possible to obtain a count of the
number of replacements performed by postfixing the command with
an 'n'. Unsuccessful searches for strings in em are indicated
by '??'.
FILES
/usr/share/em/emhelp
SEE ALSO
ed(1), ispell(1)
AUTHOR
Original code by Ken Thompson
QMC mods Feb. 76, by George Coulouris
additional mods by jrh
More mods by George March 76:
2012 port Pierre Gaston <pierre.gaston at gmail dot com>
BUGS
The underscoring in the 'x' command is sometimes incorrect on ITT terminals,
especially when the
line contains {,},\- or \!.
The ", % and & commands should restrict their scope to the dimensions
of whatever screen is in use.
Tab settings are assumed to be at every eighth character position.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- FILES
-
- SEE ALSO
-
- AUTHOR
-
- BUGS
-
This document was created by
man2html,
using the manual pages.
Time: 12:26:24 GMT, June 03, 2012