util-vserver-0.30.208

[util-vserver.git] / lib_internal / command-exec.c

diff --git a/lib_internal/command-exec.c b/lib_internal/command-exec.c
new file mode 100644 (file)
index 0000000..9669f67
--- /dev/null
+++ b/lib_internal/command-exec.c
@@ -0,0 +1,86 @@
+// $Id: command-exec.c,v 1.3 2005/03/22 15:25:54 ensc Exp $    --*- 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;
+}