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/* $OpenBSD: bcwrap.c,v 1.5 1997/09/11 22:59:37 deraadt Exp $ */
/*
* Copyright (c) 1996 Theo de Raadt <deraadt@theos.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Theo de Raadt.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* GNU bc wants to print it's copyright, if in interactive mode. The
* copyright demands it. That's stupid, ugly, and I think looks very
* gross.
*
* As a side effect, the special ^C handling in gnubc goes away,
* bringing us back to the familiar handling.
*
* Oh well, with this wrapper it's never in interactive mode.
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
int
main(argc, argv)
int argc;
char *argv[];
{
int pd[2], rfds;
int width = 1, off, n, res;
char buf[1024];
int pid, stat;
if (!(isatty(0) && isatty(1)))
execv("/usr/bin/gnubc", argv);
/* Ok, we need to go non-interactive */
if (pipe(pd) == -1) {
perror("pipe");
exit(1);
}
pid = fork();
switch(pid) {
case -1:
perror("fork");
exit(1);
case 0:
dup2(pd[0], 0); /* stdin = pipe */
close(pd[0]);
close(pd[1]);
execv("/usr/bin/gnubc", argv);
exit(1);
default:
close(pd[0]);
break;
}
width = pd[1];
while (1) {
if (waitpid(pid, &stat, WNOHANG) > 0)
exit(WEXITSTATUS(stat));
rfds = (1 << 0) || (1 << pd[1]);
switch (select(width, (fd_set *)&rfds, NULL, NULL, NULL)) {
case -1:
case 0:
break;
default:
if (rfds & (1<<0) == 0)
goto done;
n = read(0, buf, sizeof buf);
if (n == 0)
goto done;
off = 0;
while (off < n) {
res = write(pd[1], buf + off, n - off);
if (res == -1 && errno != EAGAIN)
goto done;
off += res;
}
}
}
done:
close(pd[1]);
waitpid(pid, &stat, 0);
exit(WEXITSTATUS(stat));
}
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