expand.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)expand.1	8.1	9/11/90
.TH expand 1
.SH Name
expand, unexpand \- expand tabs to spaces, and vice versa
.SH Syntax
.B expand
[\-\fItabstop\fR\|] [\-\fItabn...\fR\|] [\|\fIfile...\fR\|]
.br
.B unexpand
[\fB\-a\fR] [\|\fIfile...\fR\|]
.SH Description
.NXR "expand command"
.NXR "unexpand command"
.NXA "expand command" "fold command"
.NXR "file" "changing tabs to blanks in"
.NXR "printer" "changing tabs to blanks for"
.NXR "tab character" "changing to spaces"
The
.PN expand
command processes the named files or the standard input writing
the standard output with tabs changed into blanks.
Backspace characters are preserved into the output and decrement
the column count for tab calculations.
The
.PN expand
command is useful for pre-processing character files
(before sorting, looking at specific columns, and so forth) that
contain tabs.
.PP
If a single
.I tabstop
argument is given then tabs are set
.I tabstop
spaces apart instead of the default 8.
If multiple tabstops are given then the tabs are set at those
specific columns.
.PP
The
.PN unexpand
command
puts tabs back into the data from the standard input or the named
files and writes the result on the standard output.
By default only leading blanks and tabs
are reconverted to maximal strings of tabs.  If the
.B \-a
option is given, then tabs are inserted whenever they would compress the
resultant file by replacing two or more characters.
.SH Options
.IP \fB\-#\fR 5
Sets tabstops the specified number of spaces (#) apart.  
.IP \fB\-a\fR 
When used with unexpand, compresses file by inserting tabs for
two or more spaces.