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/*
* pipe.cc: Part of GNU CSSC.
*
* Copyright (C) 1997,1998 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*
* CSSC was originally Based on MySC, by Ross Ridge, which was
* placed in the Public Domain.
*
*
* Members of the class Pipe.
*
*/
#ifdef __GNUC__
#pragma implementation "pipe.h"
#endif
class Pipe;
#include "cssc.h"
#include "pipe.h"
#include "run.h"
#include "mylist.h"
#include "sysdep.h"
#ifdef CONFIG_SCCS_IDS
static const char rcs_id[] = "CSSC $Id: pipe.cc,v 1.2 2001/09/29 19:39:42 james_youngman Exp $";
#endif
extern int create(mystring name, int mode);
/*
* The old no-fork-provided implementation has been removed.
* This may be a problem for AmigaOS, which has no working
* fork(). Deal with that with temporary files, and new
* code. Likewise Win32.
*
* If you want a copy of the old code, mail me -- jay@gnu.org
*/
#ifdef USE_PIPE
/* Using pipes requires both fork() and pipe(). */
#ifndef HAVE_FORK
#error "HAVE_FORK must be defined if USE_PIPE is defined."
#endif
#ifndef HAVE_PIPE
#error "HAVE_PIPE must be defined if USE_PIPE is defined."
#endif
/* Head of list class wait_pid objects that haven't been reaped yet. */
class wait_pid *wait_pid::head = NULL;
/* Removes "this" from the list of unreaped wait_pid's */
void
wait_pid::unlink() {
class wait_pid *p = head;
if (p == this) {
head = next;
return;
}
while(p != NULL) {
if (p->next == this) {
p->next = next;
return;
}
p = p->next;
}
ASSERT(&wait_pid::unlink);
}
/* Waits for until the this pid's process ends and then returns its
exit status. Records the exit status of any other processes
that exits in the mean time. */
int
wait_pid::wait() {
ASSERT(pid != (pid_t)-1 && pid != 0);
if (reaped) {
pid = (pid_t)-1;
return status;
}
int st;
pid_t r = ::wait(&st);
while (r != pid) {
if (r != (pid_t)-1) {
class wait_pid *p = head;
while(p != NULL) {
if (p->pid == r) {
unlink();
p->reaped = 1;
p->status = st;
break;
}
p = p->next;
}
} else if (errno != EINTR) {
perror("wait()"); // The wait call failed.
return 0; // unsure if this is the right value to return.
}
r = ::wait(&st);
}
unlink();
pid = (pid_t)-1;
return st;
}
/* This is used to keep system dependencies out of the include files. */
NORETURN
Pipe::_exit(int ret) {
::_exit(ret);
}
/* Constructor for the class Pipe. Creates a pipe and forks, giving
the write end of the pipe to child process and the read end to the
parent process. */
Pipe::Pipe()
{
int fds[2];
if (::pipe(fds) == -1)
{
quit(errno, "pipe() failed.");
}
else
{
pid = fork();
if (pid == (pid_t)-1)
{
quit(errno, "fork() failed.");
}
else
{
if (pid == 0)
{
child = 1;
cleanup::set_in_child();
close(fds[0]);
fd = fds[1];
f = fdopen(fds[1], "w");
}
else
{
child = 0;
close(fds[1]);
fd = fds[0];
f = fdopen(fds[0], "r");
}
if (f == NULL)
{
quit(errno, "fdopen() failed.");
}
}
}
}
/* Runs the diff command with a one pipe as stdin and another pipe
as stdout. */
int
run_diff(const char *gname, Pipe &pipe_in, Pipe &pipe_out)
{
if (pipe_out.write_stream() == NULL) {
return 0;
}
close(0);
if (dup(pipe_in.fd) != 0) {
quit(errno, "dup() != 0.");
}
close(1);
if (dup(pipe_out.fd) != 1) {
quit(errno, "dup() != 1.");
}
execl(CONFIG_DIFF_COMMAND, CONFIG_DIFF_COMMAND,
#ifdef CONFIG_DIFF_SWITCHES
CONFIG_DIFF_SWITCHES,
#endif
"-", gname, (const char *) 0);
quit(errno, "execl(\"" CONFIG_DIFF_COMMAND "\") failed.");
}
#endif /* USE_PIPE */
/* Local variables: */
/* mode: c++ */
/* End: */
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