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/*
* Copyright 1998-1999, University of Notre Dame.
* Authors: Brian W. Barrett, Arun F. Rodrigues, Jeffrey M. Squyres,
* and Andrew Lumsdaine
*
* This file is part of XMPI
*
* You should have received a copy of the License Agreement for XMPI
* along with the software; see the file LICENSE. If not, contact
* Office of Research, University of Notre Dame, Notre Dame, IN 46556.
*
* Permission to modify the code and to distribute modified code is
* granted, provided the text of this NOTICE is retained, a notice that
* the code was modified is included with the above COPYRIGHT NOTICE and
* with the COPYRIGHT NOTICE in the LICENSE file, and that the LICENSE
* file is distributed with the modified code.
*
* LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.
* By way of example, but not limitation, Licensor MAKES NO
* REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY
* PARTICULAR PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS
* OR DOCUMENTATION WILL NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS
* OR OTHER RIGHTS.
*
* Additional copyrights may follow.
*
* $Id: xmpi_help.c,v 1.3 1999/11/08 06:20:24 bbarrett Exp $
*
* Function: - XMPI help
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "args.h"
#include "xmpi.h"
/*
* public functions
*/
void xmpi_help();
/*
* private functions
*/
static void childtrap();
/*
* private variables
*/
static int help_pid = 0;
/*
* xmpi_help
*
* Function: - fork-exec help
*/
void
xmpi_help()
{
char errbuf[512];
char **argv;
int pid;
struct sigaction
chld; /* SIGCHLD action */
if (help_pid > 0) return;
if (app_res.ap_helpcmd == 0 || strlen(app_res.ap_helpcmd) == 0) {
return;
}
argv = argvbreak(app_res.ap_helpcmd, ' ');
if (argv == 0) {
xmpi_error(0, "xmpi_help (argvbreak)");
} else {
chld.sa_handler = childtrap;
chld.sa_flags = SA_NOCLDSTOP;
sigemptyset(&chld.sa_mask);
sigaction(SIGCHLD, &chld, (struct sigaction *) 0);
if ((pid = fork()) < 0) {
xmpi_error(0, "xmpi_help (fork)");
}
else if (pid == 0) {
execvp(argv[0], argv);
sprintf(errbuf, "xmpi: ERROR in help command \"%s\"",
app_res.ap_helpcmd);
perror(errbuf);
exit(errno);
} else {
help_pid = pid;
}
}
}
/*
* childtrap
*
* Function: - traps child process termination
*/
static void
childtrap()
{
int status;
if (help_pid > 0) {
if (waitpid(help_pid, &status, WNOHANG) > 0) {
help_pid = 0;
}
}
}
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