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// $Id: command-exec.c 1957 2005-03-22 15:25:54Z ensc $ --*- c -*--
// Copyright (C) 2004 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
//
// 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; version 2 of the License.
//
// 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 02111-1307, USA.
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "command.h"
#include "util.h"
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>
static inline bool
initPipes(int p[2])
{
return (pipe(p)!=-1 &&
fcntl(p[1], F_SETFD, FD_CLOEXEC)!=-1);
}
bool
Command_exec(struct Command *cmd, bool do_fork)
{
int p[2];
if (cmd->params_style_==parVEC)
Vector_zeroEnd(&cmd->params.v);
if (!do_fork)
cmd->pid = 0;
else if (!initPipes(p) ||
(cmd->pid = fork())==-1) {
cmd->err = errno;
return false;
}
if (cmd->pid==0) {
char const ** argv = { 0 };
if (do_fork) close(p[0]);
switch (cmd->params_style_) {
case parVEC : argv = cmd->params.v.data; break;
case parDATA : argv = cmd->params.d; break;
default : break;
}
execv(cmd->filename ? cmd->filename : argv[0],
reinterpret_cast(char **const)(argv));
cmd->err = errno;
assert(cmd->err != 0);
if (do_fork) {
TEMP_FAILURE_RETRY(write(p[1], &cmd->err, sizeof(cmd->err)));
_exit(1); // implicates 'close(p[1])'
}
}
else {
close(p[1]);
if (read(p[0], &cmd->err, sizeof(cmd->err))==0)
cmd->err = 0;
else // cleanup zombies
while (wait4(cmd->pid, 0,0,0)==-1 &&
(errno==EINTR || errno==EAGAIN)) {};
close(p[0]);
}
return cmd->err==0;
}
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