1 files changed, 98 insertions, 0 deletions
diff --git a/src/setpgrp.c b/src/setpgrp.c
new file mode 100644
index 0000000..e1f595e
--- /dev/null
+++ b/src/setpgrp.c
@@ -0,0 +1,98 @@
+/**
+ * setpgrep — run a program in a new process group
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <unistd.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+
+
+int main(int argc, char* argv[])
+{
+  int switch_print = 0;
+  int switch_export = 0;
+  int switch_help = 0;
+  pid_t group;
+  char** args;
+  size_t off;
+  
+  for (off = 1; off < (size_t)argc; off++)
+    if (!strcmp(argv[off], "--print"))
+      switch_print = 1;
+    else if (!strcmp(argv[off], "--export"))
+      {
+	switch_export = ++off;
+	if (off == (size_t)argc)
+	  goto help;
+      }
+    else if (!strcmp(argv[off], "--help"))
+      {
+	switch_help = 1;
+	goto help;
+      }
+    else if (!strcmp(argv[off], "--"))
+      {
+	off++;
+	break;
+      }
+    else if (argv[off][0] != '-')
+      break;
+    else
+      goto help;
+  
+  group = setpgid(0, 0);
+  if (group == (pid_t)-1)
+    goto fail;
+  group = getpgrp();
+  
+  args = malloc(argc * sizeof(char*));
+  if (args == NULL)
+    goto fail;
+  
+  memcpy(args, argv + off, ((size_t)argc - off) * sizeof(char*));
+  args[argc - 1] = NULL;
+  
+  if (switch_print)
+    if (printf("%ji\n", (intmax_t)group) < 0)
+      goto fail;
+  
+  if (switch_export)
+    {
+      char group_str[3 * sizeof(pid_t) + 1];
+      if (sprintf(group_str, "%ji", (intmax_t)group) < 0)
+	goto fail;
+      if (setenv(argv[switch_export], group_str, 1) < 0)
+	goto fail;
+    }
+  
+  execvp(args[0], args);
+  
+ fail:
+  perror(*argv);
+  return 1;
+  
+ help:
+  printf("USAGE: %s [options] [--] [command...]\n", *argv);
+  printf("\n");
+  printf("    --print       Print the process group to stdout.\n");
+  printf("    --export VAR  Export the process group to the ENV environment variable.\n");
+  printf("\n");
+  return !switch_help;
+}
+