glib/glib/gspawn.h

/* gspawn.h - Process launching
 *
 *  Copyright 2000 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __G_SPAWN_H__
#define __G_SPAWN_H__

#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif

#include <glib/gerror.h>

G_BEGIN_DECLS


/* I'm not sure I remember our proposed naming convention here. */
/**
 * G_SPAWN_ERROR:
 *
 * Error domain for spawning processes. Errors in this domain will
 * be from the #GSpawnError enumeration. See #GError for information on
 * error domains.
 */
#define G_SPAWN_ERROR g_spawn_error_quark ()

/**
 * GSpawnError:
 * @G_SPAWN_ERROR_FORK: Fork failed due to lack of memory.
 * @G_SPAWN_ERROR_READ: Read or select on pipes failed.
 * @G_SPAWN_ERROR_CHDIR: Changing to working directory failed.
 * @G_SPAWN_ERROR_ACCES: execv() returned `EACCES`
 * @G_SPAWN_ERROR_PERM: execv() returned `EPERM`
 * @G_SPAWN_ERROR_TOO_BIG: execv() returned `E2BIG`
 * @G_SPAWN_ERROR_2BIG: deprecated alias for %G_SPAWN_ERROR_TOO_BIG
 * @G_SPAWN_ERROR_NOEXEC: execv() returned `ENOEXEC`
 * @G_SPAWN_ERROR_NAMETOOLONG: execv() returned `ENAMETOOLONG`
 * @G_SPAWN_ERROR_NOENT: execv() returned `ENOENT`
 * @G_SPAWN_ERROR_NOMEM: execv() returned `ENOMEM`
 * @G_SPAWN_ERROR_NOTDIR: execv() returned `ENOTDIR`
 * @G_SPAWN_ERROR_LOOP: execv() returned `ELOOP`
 * @G_SPAWN_ERROR_TXTBUSY: execv() returned `ETXTBUSY`
 * @G_SPAWN_ERROR_IO: execv() returned `EIO`
 * @G_SPAWN_ERROR_NFILE: execv() returned `ENFILE`
 * @G_SPAWN_ERROR_MFILE: execv() returned `EMFILE`
 * @G_SPAWN_ERROR_INVAL: execv() returned `EINVAL`
 * @G_SPAWN_ERROR_ISDIR: execv() returned `EISDIR`
 * @G_SPAWN_ERROR_LIBBAD: execv() returned `ELIBBAD`
 * @G_SPAWN_ERROR_FAILED: Some other fatal failure,
 *   `error->message` should explain.
 *
 * Error codes returned by spawning processes.
 */
typedef enum
{
  G_SPAWN_ERROR_FORK,   /* fork failed due to lack of memory */
  G_SPAWN_ERROR_READ,   /* read or select on pipes failed */
  G_SPAWN_ERROR_CHDIR,  /* changing to working dir failed */
  G_SPAWN_ERROR_ACCES,  /* execv() returned EACCES */
  G_SPAWN_ERROR_PERM,   /* execv() returned EPERM */
  G_SPAWN_ERROR_TOO_BIG,/* execv() returned E2BIG */
#ifndef G_DISABLE_DEPRECATED
  G_SPAWN_ERROR_2BIG = G_SPAWN_ERROR_TOO_BIG,
#endif
  G_SPAWN_ERROR_NOEXEC, /* execv() returned ENOEXEC */
  G_SPAWN_ERROR_NAMETOOLONG, /* ""  "" ENAMETOOLONG */
  G_SPAWN_ERROR_NOENT,       /* ""  "" ENOENT */
  G_SPAWN_ERROR_NOMEM,       /* ""  "" ENOMEM */
  G_SPAWN_ERROR_NOTDIR,      /* ""  "" ENOTDIR */
  G_SPAWN_ERROR_LOOP,        /* ""  "" ELOOP   */
  G_SPAWN_ERROR_TXTBUSY,     /* ""  "" ETXTBUSY */
  G_SPAWN_ERROR_IO,          /* ""  "" EIO */
  G_SPAWN_ERROR_NFILE,       /* ""  "" ENFILE */
  G_SPAWN_ERROR_MFILE,       /* ""  "" EMFLE */
  G_SPAWN_ERROR_INVAL,       /* ""  "" EINVAL */
  G_SPAWN_ERROR_ISDIR,       /* ""  "" EISDIR */
  G_SPAWN_ERROR_LIBBAD,      /* ""  "" ELIBBAD */
  G_SPAWN_ERROR_FAILED       /* other fatal failure, error->message
                              * should explain
                              */
} GSpawnError;

/**
 * G_SPAWN_EXIT_ERROR:
 *
 * Error domain used by g_spawn_check_exit_status().  The code
 * will be the program exit code.
 */
#define G_SPAWN_EXIT_ERROR g_spawn_exit_error_quark ()

/**
 * GSpawnChildSetupFunc:
 * @user_data: (closure): user data to pass to the function.
 *
 * Specifies the type of the setup function passed to g_spawn_async(),
 * g_spawn_sync() and g_spawn_async_with_pipes(), which can, in very
 * limited ways, be used to affect the child's execution.
 *
 * On POSIX platforms, the function is called in the child after GLib
 * has performed all the setup it plans to perform, but before calling
 * exec(). Actions taken in this function will only affect the child,
 * not the parent.
 *
 * On Windows, the function is called in the parent. Its usefulness on
 * Windows is thus questionable. In many cases executing the child setup
 * function in the parent can have ill effects, and you should be very
 * careful when porting software to Windows that uses child setup
 * functions.
 *
 * However, even on POSIX, you are extremely limited in what you can
 * safely do from a #GSpawnChildSetupFunc, because any mutexes that were
 * held by other threads in the parent process at the time of the fork()
 * will still be locked in the child process, and they will never be
 * unlocked (since the threads that held them don't exist in the child).
 * POSIX allows only async-signal-safe functions (see signal(7)) to be
 * called in the child between fork() and exec(), which drastically limits
 * the usefulness of child setup functions.
 *
 * In particular, it is not safe to call any function which may
 * call malloc(), which includes POSIX functions such as setenv().
 * If you need to set up the child environment differently from
 * the parent, you should use g_get_environ(), g_environ_setenv(),
 * and g_environ_unsetenv(), and then pass the complete environment
 * list to the `g_spawn...` function.
 */
typedef void (* GSpawnChildSetupFunc) (gpointer user_data);

/**
 * GSpawnFlags:
 * @G_SPAWN_DEFAULT: no flags, default behaviour
 * @G_SPAWN_LEAVE_DESCRIPTORS_OPEN: the parent's open file descriptors will
 *     be inherited by the child; otherwise all descriptors except stdin,
 *     stdout and stderr will be closed before calling exec() in the child.
 * @G_SPAWN_DO_NOT_REAP_CHILD: the child will not be automatically reaped;
 *     you must use g_child_watch_add() yourself (or call waitpid() or handle
 *     `SIGCHLD` yourself), or the child will become a zombie.
 * @G_SPAWN_SEARCH_PATH: `argv[0]` need not be an absolute path, it will be
 *     looked for in the user's `PATH`.
 * @G_SPAWN_STDOUT_TO_DEV_NULL: the child's standard output will be discarded,
 *     instead of going to the same location as the parent's standard output.
 * @G_SPAWN_STDERR_TO_DEV_NULL: the child's standard error will be discarded.
 * @G_SPAWN_CHILD_INHERITS_STDIN: the child will inherit the parent's standard
 *     input (by default, the child's standard input is attached to `/dev/null`).
 * @G_SPAWN_FILE_AND_ARGV_ZERO: the first element of `argv` is the file to
 *     execute, while the remaining elements are the actual argument vector
 *     to pass to the file. Normally g_spawn_async_with_pipes() uses `argv[0]`
 *     as the file to execute, and passes all of `argv` to the child.
 * @G_SPAWN_SEARCH_PATH_FROM_ENVP: if `argv[0]` is not an abolute path,
 *     it will be looked for in the `PATH` from the passed child environment.
 *     Since: 2.34
 * @G_SPAWN_CLOEXEC_PIPES: create all pipes with the `O_CLOEXEC` flag set.
 *     Since: 2.40
 *
 * Flags passed to g_spawn_sync(), g_spawn_async() and g_spawn_async_with_pipes().
 */
typedef enum
{
  G_SPAWN_DEFAULT                = 0,
  G_SPAWN_LEAVE_DESCRIPTORS_OPEN = 1 << 0,
  G_SPAWN_DO_NOT_REAP_CHILD      = 1 << 1,
  /* look for argv[0] in the path i.e. use execvp() */
  G_SPAWN_SEARCH_PATH            = 1 << 2,
  /* Dump output to /dev/null */
  G_SPAWN_STDOUT_TO_DEV_NULL     = 1 << 3,
  G_SPAWN_STDERR_TO_DEV_NULL     = 1 << 4,
  G_SPAWN_CHILD_INHERITS_STDIN   = 1 << 5,
  G_SPAWN_FILE_AND_ARGV_ZERO     = 1 << 6,
  G_SPAWN_SEARCH_PATH_FROM_ENVP  = 1 << 7,
  G_SPAWN_CLOEXEC_PIPES          = 1 << 8
} GSpawnFlags;

GLIB_AVAILABLE_IN_ALL
GQuark g_spawn_error_quark (void);
GLIB_AVAILABLE_IN_ALL
GQuark g_spawn_exit_error_quark (void);

GLIB_AVAILABLE_IN_ALL
gboolean g_spawn_async (const gchar           *working_directory,
                        gchar                **argv,
                        gchar                **envp,
                        GSpawnFlags            flags,
                        GSpawnChildSetupFunc   child_setup,
                        gpointer               user_data,
                        GPid                  *child_pid,
                        GError               **error);


/* Opens pipes for non-NULL standard_output, standard_input, standard_error,
 * and returns the parent's end of the pipes.
 */
GLIB_AVAILABLE_IN_ALL
gboolean g_spawn_async_with_pipes (const gchar          *working_directory,
                                   gchar               **argv,
                                   gchar               **envp,
                                   GSpawnFlags           flags,
                                   GSpawnChildSetupFunc  child_setup,
                                   gpointer              user_data,
                                   GPid                 *child_pid,
                                   gint                 *standard_input,
                                   gint                 *standard_output,
                                   gint                 *standard_error,
                                   GError              **error);


/* If standard_output or standard_error are non-NULL, the full
 * standard output or error of the command will be placed there.
 */

GLIB_AVAILABLE_IN_ALL
gboolean g_spawn_sync         (const gchar          *working_directory,
                               gchar               **argv,
                               gchar               **envp,
                               GSpawnFlags           flags,
                               GSpawnChildSetupFunc  child_setup,
                               gpointer              user_data,
                               gchar               **standard_output,
                               gchar               **standard_error,
                               gint                 *exit_status,
                               GError              **error);

GLIB_AVAILABLE_IN_ALL
gboolean g_spawn_command_line_sync  (const gchar          *command_line,
                                     gchar               **standard_output,
                                     gchar               **standard_error,
                                     gint                 *exit_status,
                                     GError              **error);
GLIB_AVAILABLE_IN_ALL
gboolean g_spawn_command_line_async (const gchar          *command_line,
                                     GError              **error);

GLIB_AVAILABLE_IN_2_34
gboolean g_spawn_check_exit_status (gint      exit_status,
				    GError  **error);

GLIB_AVAILABLE_IN_ALL
void g_spawn_close_pid (GPid pid);

G_END_DECLS

#endif /* __G_SPAWN_H__ */