don't let users create their own symbol table for the running kernel

[unix-history] / usr / src / usr.bin / ex / ex.1

.\" Copyright (c) 1980, 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.roff%
.\"
.\"	@(#)ex.1	6.9 (Berkeley) %G%
.\"
.Dd 
.Dt EX 1
.Os BSD 4
.Sh NAME
.Nm ex , edit
.Nd text editor
.Sh SYNOPSIS
.Nm ex
.Op Fl
.Op Fl v
.Op Fl t Ar tag
.Op Fl r
.Oo
.Op Cm + Ns Ar command
.Oc
.Op Fl l
.Ar name
\&...
.Nm edit
.Op ex options
.Sh DESCRIPTION
.Nm \&Ex
is the root of a family of editors:
.Nm edit ,
.Nm ex
and
.Nm vi .
.Nm \&Ex
is a superset of
.Xr ed ,
with the most notable extension being a display editing facility.
Display based editing is the focus of
.Xr vi 1
and requires a
.Tn CRT .
.Pp
For users unfamiliar with
.Xr ed 1 ,
the editor
.Nm edit
is probably easier to learn.
It avoids some of the complexities of
.Nm ex
used mostly by systems programmers and persons comfortable with the
.Xr ed 1
editor.
.Sh DOCUMENTATION
The following documentation is found in the
.Dq "\\*(tNUNIX\\*(fP User's Manual Supplementary Documents" :
.Pp
.%T "Edit: A tutorial"
provides a comprehensive introduction to
.Nm edit
assuming no previous knowledge of computers or the
.Tn UNIX
system.
.Pp
.%T "Ex Reference Manual \- Version 3.7"
is a comprehensive and complete manual for the command mode features
of
.Nm ex ,
but you cannot learn to use the editor by reading it.
For an introduction to
more advanced forms of editing using the command mode of
.Nm ex
see the editing documents written by Brian Kernighan for the editor
.Xr ed 1 ;
the material in the introductory and advanced documents works also with
.Nm ex .
.Pp
.%T "An Introduction to Display Editing with Vi"
introduces the display editor
.Xr vi 1
and provides reference material on
.Xr vi 1 .
In addition, the
.%T "Vi Quick Reference"
card summarizes the commands
of
.Xr vi 1
in a useful, functional way, and is useful with the
introduction.
.Sh ENVIRONMENT
The
.Nm
command uses the following environment variables.
.Bl -tag -width TERMCAP
.It Ev EXINIT
User specified startup values for
.Nm ex .
.It Ev HOME
Default directory to search for
the file
.Pa ~/.exrc
.It Ev SHELL
Shell used for
.Em escaped
commands (with the
.Ic \&!
command).
.It Ev TERM
Terminal type.
.It Ev TERMCAP
Alternate termcap file.
.El
.Sh FILES
.Bl -tag -width /usr/libexec/ex?.?preserve -compact
.It Pa  /usr/libexec/ex?.?strings
error messages
.It Pa  /usr/libexec/ex?.?recover
recover command
.It Pa  /usr/libexec/ex?.?preserve
preserve command
.It Pa  /usr/share/misc/termcap
describes capabilities of terminals
.It Pa  ~/.exrc
editor startup file
.It Pa /tmp/Ex Ns Ar nnnnn
editor temporary
.It Pa /tmp/Rx Ns Ar nnnnn
named buffer temporary
.It Pa /var/preserve
preservation directory
.El
.Sh SEE ALSO
.Xr awk 1 ,
.Xr ed 1 ,
.Xr grep 1 ,
.Xr sed 1 ,
.Xr grep 1 ,
.Xr vi 1 ,
.Xr termcap 5 ,
.Xr environ 7
.Sh HISTORY
.Nm \&Ex
appeared in
.Bx 3 .
.Sh BUGS
The
.Ic undo
command causes all marks to be lost on lines changed and then restored
if the marked lines were changed.
.Pp
.Ic Undo
never clears the buffer modified condition.
.Pp
The
.Ic z
command prints a number of logical rather than physical lines.
More than a screen full of output may result if long lines are present.
.Pp
File input/output errors don't print a name if the command line
.Sq Fl
option is used.
.Pp
There is no easy way to do a single scan ignoring case.
.Pp
The editor does not warn if text is placed in named buffers and not used
before exiting the editor.
.Pp
Null characters are discarded in input files, and cannot appear in resultant
files.