UNIFDEF(1)                                                          UNIFDEF(1)



NAME
       unifdef - remove ifdef’ed lines

SYNOPSIS
       unifdef [ -t -l -c -D_s_y_m -U_s_y_m -id_s_y_m -iu_s_y_m ] ...  [ file ]

DESCRIPTION
       _U_n_i_f_d_e_f  is useful for removing ifdef’ed lines from a file while other‐
       wise leaving the file alone.  _U_n_i_f_d_e_f 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 -D_s_y_m or undefined -U_s_y_m 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 _s_y_m
       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 _u_n_i_f_d_e_f 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 _u_n_i_f_d_e_f 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  -id_s_y_m  and
       -iu_s_y_m similar to -D_s_y_m and -U_s_y_m above.

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

       _U_n_i_f_d_e_f  copies its output to _s_t_d_o_u_t and will take its input from _s_t_d_i_n
       if no _f_i_l_e argument is given.  If the -c argument  is  specified,  then
       the  operation  of  _u_n_i_f_d_e_f  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 _c_p_p consructs such as

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


AUTHOR
       Dave Yost



4.3 Berkeley Distribution       April 29, 1985                      UNIFDEF(1)