util-vserver-0.30.208

[util-vserver.git] / src / vshelper-sync.c

diff --git a/src/vshelper-sync.c b/src/vshelper-sync.c
new file mode 100644 (file)
index 0000000..921f12d
--- /dev/null
+++ b/src/vshelper-sync.c
@@ -0,0 +1,111 @@
+// $Id: vshelper-sync.c,v 1.5 2005/05/05 09:21:21 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 "util.h"
+
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <assert.h>
+
+static void
+showHelp(int fd, char const *cmd, int res)
+{
+  WRITE_MSG(fd, "Usage:  ");
+  WRITE_STR(fd, cmd);
+  WRITE_MSG(fd,
+           " [--] <pipe> <timeout>\n\n"
+           "Please report bugs to " PACKAGE_BUGREPORT "\n");
+  exit(res);
+}
+
+static void
+showVersion()
+{
+  WRITE_MSG(1,
+           "vshelper-sync " VERSION " -- waits for data from a pipe"
+           "This program is part of " PACKAGE_STRING "\n\n"
+           "Copyright (C) 2004 Enrico Scholz\n"
+           VERSION_COPYRIGHT_DISCLAIMER);
+  exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+  int                  fd;
+  int                  idx = 1;
+  struct timeval       timeout;
+
+  if (argc>=2) {
+    if (strcmp(argv[1], "--help")   ==0) showHelp(1, argv[0], 0);
+    if (strcmp(argv[1], "--version")==0) showVersion();
+    if (strcmp(argv[1], "--")       ==0) ++idx;
+  }
+
+  if (argc<idx+2) {
+    WRITE_MSG(2, "Not enough parameters; use '--help' for more information\n");
+    return EXIT_FAILURE;
+  }
+
+  fd = open(argv[idx], O_RDONLY|O_NONBLOCK, 0);
+  if (fd==-1) {
+    perror("vshelper-sync: open()");
+    return EXIT_FAILURE;
+  }
+
+  timeout.tv_sec  = atoi(argv[idx+1]);
+  timeout.tv_usec = 0;
+
+  for (;;) {
+    char       buf[512];
+    ssize_t    len;
+    fd_set     fds;
+
+    FD_ZERO(&fds);
+    FD_SET(fd, &fds);
+
+#ifndef __linux__
+#  error vshelper relies on the Linux select() behavior (timeout holds remaining time)
+#endif
+
+    switch (select(fd+1, &fds, 0,0, &timeout)) {
+      case 0   :  return EXIT_FAILURE; // timeout
+      case -1  :
+       perror("vshelper: select()");
+       return EXIT_FAILURE;
+      default  :  break;
+    }
+
+    assert(FD_ISSET(fd, &fds));
+
+    len = read(fd,buf,sizeof buf);
+    if (len==0) break;
+    if (len==-1) {
+      perror("vshelper-sync: read()");
+      return EXIT_FAILURE;
+    }
+  }
+
+  return EXIT_SUCCESS;
+}