unexpand(1)
NAME
expand, unexpand - expand TAB characters to SPACE charac-
ters, and vice versa
SYNOPSIS
expand [-t tablist] [file...]
expand [-tabstop] [ -tab1, tab2,. . ., tabn] [file...]
unexpand [-a] [-t tablist] [file...]
DESCRIPTION
The expand utility copies files (or the standard input) to
the standard output, with TAB characters expanded to SPACE
characters. BACKSPACE characters are preserved into the out-
put and decrement the column count for TAB calculations.
expand is useful for pre-processing character files (before
sorting, looking at specific columns, and so forth) that
contain TAB characters.
unexpand copies files (or the standard input) to the stan-
dard output, putting TAB characters back into the data. By
default, only leading SPACE and TAB characters are converted
to strings of tabs, but this can be overridden by the -a
option (see the OPTIONS section below).
OPTIONS
The following options are supported for expand:
-t tablist
Specifies the tab stops. The argument tablist must
consist of a single positive decimal integer or multi-
ple positive decimal integers, separated by blank
characters or commas, in ascending order. If a single
number is given, tabs will be set tablist column posi-
tions apart instead of the default 8. If multiple
numbers are given, the tabs will be set at those
specific column positions.
Each tab-stop position N must be an integer value
greater than zero, and the list must be in strictly
ascending order. This is taken to mean that, from the
start of a line of output, tabbing to position N
causes the next character output to be in the (N+1)th
column position on that line.
In the event of expand having to process a tab charac-
ter at a position beyond the last of those specified
in a multiple tab-stop list, the tab character is
replaced by a single space character in the output.
-tabstop
Specifies as a single argument, sets TAB characters
tabstop SPACE characters apart instead of the default
8.
-tab1,tab2,...,tabn
Sets TAB characters at the columns specified by
-tab1,tab2,...,tabn
The following options are supported for unexpand:
-a Inserts TAB characters when replacing a run of two or
more SPACE characters would produce a smaller output
file.
-t tablist
Specifies the tab stops. The option-argument tablist
must be a single argument consisting of a single posi-
tive decimal integer or multiple positive decimal
integers, separated by blank characters or commas, in
ascending order. If a single number is given, tabs
will be set tablist column positions apart instead of
the default 8. If multiple numbers are given, the tabs
will be set at those specific column positions. Each
tab-stop position N must be an integer value greater
than zero, and the list must be in strictly ascending
order. This is taken to mean that, from the start of a
line of output, tabbing to position N will cause the
next character output to be in the (N+1)th column
position on that line. When the -t option is not
specified, the default is the equivalent of specifying
-t 8 (except for the interaction with -a, described
below).
No space-to-tab character conversions occur for char-
acters at positions beyond the last of those specified
in a multiple tab-stop list.
When -t is specified, the presence or absence of the
-a option is ignored; conversion will not be limited
to the processing of leading blank characters.
OPERANDS
The following ooperand is supported for expand and unexpand:
file The path name of a text file to be used as input.
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment
variables that affect the execution of expand and unexpand:
LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
EXIT STATUS
The following exit values are returned:
0 Successful completion
>0 An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWesu |
|_____________________________|_____________________________|
| CSI | enabled |
|_____________________________|_____________________________|
| Interface Stability | Standard |
|_____________________________|_____________________________|
SEE ALSO
tabs(1), attributes(5), environ(5), standards(5)
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