/*
* Copyright (C) 2004 The X.Org fundation
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is fur-
* nished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of the X.Org fundation
* shall not be used in advertising or otherwise to promote the sale,
* use or other dealings in this Software without prior written
* authorization from the X.Org fundation.
*/
/*
** This is a secure but NOT 100% compatible replacement for popen()
** Note: - don't use pclose() use fclose() for closing the returned
** filedesc.!!!
**
** Known Bugs: - unable to use i/o-redirection like > or <
** Author: - Thomas Biege <thomas@suse.de>
** Credits: - Andreas Pfaller <a.pfaller@pop.gun.de> for fixing a SEGV when
** calling strtok()
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#define __SEC_POPEN_TOKEN " "
FILE *Xpms_popen(char *cmd, const char *type)
{
pid_t pid;
int pfd[2];
int rpipe = 0, wpipe = 0, i;
char **argv;
char *ptr;
char *cmdcpy;
if(cmd == NULL || cmd == "")
return(NULL);
if(type[0] != 'r' && type[0] != 'w')
return(NULL);
if ((cmdcpy = strdup(cmd)) == NULL)
return(NULL);
argv = NULL;
if( (ptr = strtok(cmdcpy, __SEC_POPEN_TOKEN)) == NULL)
{
free(cmdcpy);
return(NULL);
}
for(i = 0;; i++)
{
if( ( argv = (char **) realloc(argv, (i+1) * sizeof(char *)) ) == NULL)
{
free(cmdcpy);
return(NULL);
}
if( (*(argv+i) = (char *) malloc((strlen(ptr)+1) * sizeof(char))) == NULL)
{
free(cmdcpy);
return(NULL);
}
strcpy(argv[i], ptr);
if( (ptr = strtok(NULL, __SEC_POPEN_TOKEN)) == NULL)
{
if( ( argv = (char **) realloc(argv, (i+2) * sizeof(char *))) == NULL)
{
free(cmdcpy);
return(NULL);
}
argv[i+1] = NULL;
break;
}
}
if(type[0] == 'r')
rpipe = 1;
else
wpipe = 1;
if (pipe(pfd) < 0)
{
free(cmdcpy);
return(NULL);
}
if((pid = fork()) < 0)
{
close(pfd[0]);
close(pfd[1]);
free(cmdcpy);
return(NULL);
}
if(pid == 0) /* child */
{
if((pid = fork()) < 0)
{
close(pfd[0]);
close(pfd[1]);
free(cmdcpy);
return(NULL);
}
if(pid > 0)
{
exit(0); /* child nr. 1 exits */
}
/* child nr. 2 */
if(rpipe)
{
close(pfd[0]); /* close reading end, we don't need it */
dup2(STDOUT_FILENO, STDERR_FILENO);
if (pfd[1] != STDOUT_FILENO)
dup2(pfd[1], STDOUT_FILENO); /* redirect stdout to writing end of pipe */
}
else
{
close(pfd[1]); /* close writing end, we don't need it */
if (pfd[0] != STDIN_FILENO)
dup2(pfd[0], STDIN_FILENO); /* redirect stdin to reading end of pipe */
}
if(strchr(argv[0], '/') == NULL)
execvp(argv[0], argv); /* search in $PATH */
else
execv(argv[0], argv);
close(pfd[0]);
close(pfd[1]);
free(cmdcpy);
return(NULL); /* exec failed.. ooops! */
}
else /* parent */
{
waitpid(pid, NULL, 0); /* wait for child nr. 1 */
if(rpipe)
{
close(pfd[1]);
free(cmdcpy);
return(fdopen(pfd[0], "r"));
}
else
{
close(pfd[0]);
free(cmdcpy);
return(fdopen(pfd[1], "w"));
}
}
}