src/process.h

   1 /* process.h -- header for child process routines for vlock,
   2  *              the VT locking program for linux
   3  *
   4  * This program is copyright (C) 2007 Frank Benkstein, and is free
   5  * software which is freely distributable under the terms of the
   6  * GNU General Public License version 2, included as the file COPYING in this
   7  * distribution.  It is NOT public domain software, and any
   8  * redistribution not permitted by the GNU General Public License is
   9  * expressly forbidden without prior written permission from
  10  * the author.
  11  *
  12  */
  13
  14 #pragma once
  15
  16 #include <stdbool.h>
  17 #include <sys/types.h>
  18 #include <glib.h>
  19
  20 /* Errors */
  21 #define VLOCK_PROCESS_ERROR vlock_process_error_quark()
  22 GQuark vlock_plugin_error_quark(void);
  23
  24 enum {
  25   VLOCK_PROCESS_ERROR_FAILED,
  26 };
  27
  28 /* Wait for the given amount of time for the death of the given child process.
  29  * If the child process dies in the given amount of time or already was dead
  30  * true is returned and false otherwise. */
  31 bool wait_for_death(pid_t pid, long sec, long usec);
  32
  33 /* Try hard to kill the given child process. */
  34 void ensure_death(pid_t pid);
  35
  36 #define NO_REDIRECT (-2)
  37 #define REDIRECT_DEV_NULL (-3)
  38 #define REDIRECT_PIPE (-4)
  39
  40 struct child_process {
  41   /* Function that will be run in the child. */
  42   int (*function)(void *argument);
  43   /* Argument for the function. */
  44   void *argument;
  45   /* First argument to execv. */
  46   const char *path;
  47   /* Second argument to execv. */
  48   const char *const *argv;
  49   /* The child's stdin. */
  50   int stdin_fd;
  51   /* The child's stdout. */
  52   int stdout_fd;
  53   /* The child's stderr. */
  54   int stderr_fd;
  55   /* The child's PID. */
  56   pid_t pid;
  57 };
  58
  59 /* Create a new child process.  All file descriptors except stdin, stdout and
  60  * stderr are closed and privileges are dropped.  All fields of the child
  61  * struct except pid must be set.  If a stdio file descriptor field has the
  62  * special value of REDIRECT_DEV_NULL it is redirected from or to /dev/null.
  63  * If it has the value REDIRECT_PIPE a pipe will be created and one end will be
  64  * connected to the respective descriptor of the child.  The file descriptor of
  65  * the other end is stored in the field after the call.  It is up to the caller
  66  * to close the pipe descriptor(s). */
  67 bool create_child(struct child_process *child, GError **error);