builtins/psize.c

   1 /* psize.c - Find pipe size. */
   2
   3 /* Copyright (C) 1987, 1991 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 /*  Write output in 128-byte chunks until we get a sigpipe or write gets an
  22     EPIPE.  Then report how many bytes we wrote.  We assume that this is the
  23     pipe size. */
  24 #include <config.h>
  25
  26 #if defined (HAVE_UNISTD_H)
  27 #  ifdef _MINIX
  28 #    include <sys/types.h>
  29 #  endif
  30 #  include <unistd.h>
  31 #endif
  32
  33 #include <stdio.h>
  34 #ifndef _MINIX
  35 #include "../bashtypes.h"
  36 #endif
  37 #include <signal.h>
  38 #include <errno.h>
  39
  40 #include "../command.h"
  41 #include "../general.h"
  42 #include "../sig.h"
  43
  44 #ifndef errno
  45 extern int errno;
  46 #endif
  47
  48 int nw;
  49
  50 sighandler
  51 sigpipe (sig)
  52      int sig;
  53 {
  54   fprintf (stderr, "%d\n", nw);
  55   exit (0);
  56 }
  57
  58 int
  59 main (argc, argv)
  60      int argc;
  61      char **argv;
  62 {
  63   char buf[128];
  64   register int i;
  65
  66   for (i = 0; i < 128; i++)
  67     buf[i] = ' ';
  68
  69   signal (SIGPIPE, sigpipe);
  70
  71   nw = 0;
  72   for (;;)
  73     {
  74       int n;
  75       n = write (1, buf, 128);
  76       nw += n;
  77     }
  78   return (0);
  79 }