4.3BSD - /usr/man/cat1/unifdef.0

UNIFDEF(1)                                                          UNIFDEF(1)


NAME
       unifdef - remove ifdef’ed lines

SYNOPSIS
       unifdef [ -t -l -c -Dsym -Usym -idsym -iusym ] ...  [ file ]

DESCRIPTION
       Unifdef  is useful for removing ifdef’ed lines from a file while other‐
       wise leaving the file alone.  Unifdef is like a stripped-down C prepro‐
       cessor:  it  is  smart enough to deal with the nested ifdefs, comments,
       single and double quotes of C syntax so that it can do its job, but  it
       doesn’t  do any including or interpretation of macros.  Neither does it
       strip out comments, though it recognizes and ignores them.  You specify
       which  symbols  you want defined -Dsym or undefined -Usym and the lines
       inside those ifdefs will be copied to the output or removed  as  appro‐
       priate.   The  ifdef, ifndef, else, and endif lines associated with sym
       will also be removed.  Ifdefs involving symbols you don’t  specify  are
       untouched  and  copied out along with their associated ifdef, else, and
       endif lines.  If an ifdef X occurs nested inside another ifdef X,  then
       the  inside  ifdef is treated as if it were an unrecognized symbol.  If
       the same symbol appears in more  than  one  argument,  only  the  first
       occurrence is significant.

       The  -l option causes unifdef to replace removed lines with blank lines
       instead of deleting them.

       If you use ifdefs to delimit non-C lines,  such  as  comments  or  code
       which  is  under construction, then you must tell unifdef which symbols
       are used for that purpose so that it won’t try to parse for quotes  and
       comments  in those ifdef’ed lines.  You specify that you want the lines
       inside certain ifdefs to be ignored but  copied  out  with  -idsym  and
       -iusym similar to -Dsym and -Usym above.

       If  you  want  to  use  unifdef for plain text (not C code), use the -t
       option.  This makes unifdef refrain from attempting to  recognize  com‐
       ments and single and double quotes.

       Unifdef  copies its output to stdout and will take its input from stdin
       if no file argument is given.  If the -c argument  is  specified,  then
       the  operation  of  unifdef  is complemented, i.e. the lines that would
       have been removed or blanked are retained and vice versa.

SEE ALSO
       diff(1)

DIAGNOSTICS
       Premature EOF, inappropriate else or endif.

       Exit status is 0 if output is exact copy of input, 1 if not, 2 if trou‐
       ble.

BUGS
       Does not know how to deal with cpp consructs such as

            #if  defined(X) || defined(Y)


AUTHOR
       Dave Yost


4.3 Berkeley Distribution       April 29, 1985                      UNIFDEF(1)