expand(1)

NAME
     expand - convert tabs to spaces

SYNOPSIS
     expand [ -t tablist ] [ file ]

DESCRIPTION
     The expand utility writes files or the standard input to the standard
     output with tab characters replaced with one or more space characters
     needed to pad to the next tab stop. Any backspace characters will be
     copied to the output and cause the column position count for tab stop
     calculations to be decremented; the column position count will not be
     decremented below zero.

OPTIONS
     expand may be used with the following options:

     -t tablist
          Specify the tab stops. The argument tablist must consist of a single
          positive 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
          causes the next character be in the (N+1)th column position on that
          line.

          In the event of expand having to process a tab character 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.

OPERANDS
     The following operand is supported:

     -t file   The pathname of a text file to be used as input.

STDIN
     See INPUT FILES.

INPUT FILES
     Input files must be text files.

ENVIRONMENT VARIABLES
     The following environment variables affect the execution of expand:

     LANG      Provide a default value for the internationalisation variables
     that are unset or null. If LANG is unset or null, the corresponding value
     from the implementation-specific default locale will be used. If any of
     the internationalisation variables contains an invalid setting, the
     utility will behave as if none of the variables had been defined.

     LC_ALL      If set to a non-empty string value, override the values of
     all the other internationalisation variables.

     LC_CTYPE      Determine the locale for the interpretation of sequences of
     bytes of text data as characters (for example, single- as opposed to
     multi-byte characters in arguments and input files), the processing of
     tab and space characters, and for the determination of the width in
     column positions each character would occupy on a constant-width font
     output device.

     LC_MESSAGES      Determine the locale that should be used to affect the
     format and contents of diagnostic messages written to standard error.


ASYNCHRONOUS EVENTS
     Default.


STDOUT
     The standard output is equivalent to the input files with tab characters
     converted into the appropriate number of space characters.


STDERR
     Used only for diagnostic messages.


OUTPUT FILES
     None.


EXTENDED DESCRIPTION
     None.


EXIT STATUS
     The following exit values are returned:

     0 Successful completion.

     >0 An error occured.


CONSEQUENCES OF ERRORS
     The expand utility will terminate with an error message and non-zero exit
     status upon encountering difficulties accessing one of the file operands.

APPLICATION USAGE
     None.


EXAMPLES
     None.


FUTURE DIRECTIONS
     None.


SEE ALSO
     tabs, unexpand


CHANGE HISTORY
     First released in Issue 4.