expand - Expand tabs to spaces

Format

  • expand [-B] [-t tablist] [-W option[option] ... [file ... file ...]
  • expand -tabstop] [-tab1,tab2,...,tabn] [-B] [-W option[option] ... [file ... file ...]

Description

expand reads text input from the files that are specified on the command line, converts tabs into spaces, and writes the result to the standard output (stdout). If you do not specify any files on the command line, expand reads from the standard input (stdin).

expand preserves backspace characters. By default, tab stops are set every eight columns. A tab after the last tabstop is replaced by a space.

Options

The first syntax of expand supports the following options:
-B
Disables the automatic conversion of tagged files. This option is ignored if the filecodeset or pgmcodeset options (-W option) are specified.
-t tablist
Sets tab stops at positions that are indicated by tablist. Numbers in tablist must be in ascending order (origin 0) and separated by commas or blanks; however, the list must be one argument so you need shell quoting if you are using blanks. The list can consist of a single number, in which case tabs are set every tablist positions apart.
-W option[,option]...
Specifies z/OS-specific options. The option keywords are case-sensitive. Possible options are:
filecodeset=codeset
Performs text conversion from one code set to another when reading from the file. The coded character set of the file is codeset. codeset can be a code set name that is known to the system or a numeric coded character set identifier (CCSID). Note that the command iconv -l lists existing CCSIDs along with their corresponding code set names. The filecodeset and pgmcodeset options can be used on files with any file tag.

If pgmcodeset is specified but filecodeset is omitted, then the default file code set is ISO8859-1 even if the file is tagged with a different code set. If neither filecodeset nor pgmcodeset is specified, text conversion will not occur unless automatic conversion is enabled or the _TEXT_CONV environment variable indicates text conversion. For more information about text conversion, see Controlling text conversion for z/OS UNIX shell commands.

If filecodeset or pgmcodeset is specified, then automatic conversion is disabled for this command invocation and the -B option is ignored if it is also specified.

The only supported values for filecodeset are ISO8859-1 and 819.
pgmcodeset=codeset
Performs text conversion from one code set to another when reading from the file. The coded character set of the program (command) is codeset. codeset can be a code set name that is known to the system or a numeric coded character set identifier (CCSID). Note that the command iconv -l lists existing CCSIDs along with their corresponding code set names. The filecodeset and pgmcodeset options can be used on files with any file tag.

If filecodeset is specified but pgmcodeset is omitted, then the default program code set is IBM-1047. If neither filecodeset nor pgmcodeset is specified, text conversion will not occur unless automatic conversion is enabled or the _TEXT_CONV environment variable indicates text conversion. For more information about text conversion, see Controlling text conversion for z/OS UNIX shell commands.

If filecodeset or pgmcodeset is specified, then automatic conversion is disabled for this command invocation and the -B option is ignored if it is also specified.

The only supported values for pgmcodeset are IBM-1047 and 1047.

The second syntax of expand (which the POSIX standard considers obsolete) supports the following options:
-tabstop
Sets tab stops every tabstop columns.
--tab1,tab2,...,tabn
Sets tab stops at each column tab1,tab2 and so on (origin 0).

Examples

  1. To convert tabs in a text file to spaces that are 10 positions apart: 
    expand -t 10 myTextFile
  2. To convert tabs in a text file containing ASCII characters to spaces, assuming that
    • The text file is untagged and you do not want to tag it or enable automatic conversion, and
    • You cannot alter the tag (for example, you are displaying an untagged public text file or a read-only text file).
    then issue: 
    expand -W filecodeset=ISO8859-1,pgmcodeset=IBM-1047 myAsciiFile
  3. To convert tabs in a text file containing EBCDIC characters to spaces, assuming that automatic conversion has been enabled but the text file is incorrectly tagged as UTF-8: 
    expand -B myTextFile

Localization

expand uses the following localization environment variables:
  • LANG
  • LC_ALL
  • LC_CTYPE
  • LC_MESSAGES
  • NLSPATH

Environment variables

expand uses the following environment variable:
_TEXT_CONV
Contains text conversion information for the command. The text conversion information is not used when either the -B option or the filecodeset or pgmcodeset option (-W option) is specified. For more information about text conversion, see Controlling text conversion for z/OS UNIX shell commands.

Exit values

0
Successful completion.
1
Failure due to any of the following reasons:
  • Cannot open the input file.
  • Insufficient memory.
  • Incorrect tab stop specification.
  • The code set is not valid.
  • Could not turn off automatic conversion.
  • Could not perform requested text conversion.

Portability

POSIX.2 User Portability Extension, X/Open Portability Guide, 4.2BSD and later.

The -B and -W options are extensions of the POSIX standard.

Related information

pr, unexpand