$NetBSD: patch-ar,v 1.1 2005/06/14 18:10:37 jlam Exp $

--- /dev/null	2005-06-14 01:17:00.000000000 -0400
+++ lib/s_popen.c	2005-06-14 00:03:23.000000000 -0400
@@ -0,0 +1,181 @@
+/*
+ * 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 *s_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"));
+    }
+
+  }
+}
+