glib/gspawn.h

   1 /* gspawn.h - Process launching
   2  *
   3  *  Copyright 2000 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public License
  16  * along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef __G_SPAWN_H__
  20 #define __G_SPAWN_H__
  21
  22 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  23 #error "Only <glib.h> can be included directly."
  24 #endif
  25
  26 #include <glib/gerror.h>
  27
  28 G_BEGIN_DECLS
  29
  30
  31 /* I'm not sure I remember our proposed naming convention here. */
  32 /**
  33  * G_SPAWN_ERROR:
  34  *
  35  * Error domain for spawning processes. Errors in this domain will
  36  * be from the #GSpawnError enumeration. See #GError for information on
  37  * error domains.
  38  */
  39 #define G_SPAWN_ERROR g_spawn_error_quark ()
  40
  41 /**
  42  * GSpawnError:
  43  * @G_SPAWN_ERROR_FORK: Fork failed due to lack of memory.
  44  * @G_SPAWN_ERROR_READ: Read or select on pipes failed.
  45  * @G_SPAWN_ERROR_CHDIR: Changing to working directory failed.
  46  * @G_SPAWN_ERROR_ACCES: execv() returned `EACCES`
  47  * @G_SPAWN_ERROR_PERM: execv() returned `EPERM`
  48  * @G_SPAWN_ERROR_TOO_BIG: execv() returned `E2BIG`
  49  * @G_SPAWN_ERROR_2BIG: deprecated alias for %G_SPAWN_ERROR_TOO_BIG
  50  * @G_SPAWN_ERROR_NOEXEC: execv() returned `ENOEXEC`
  51  * @G_SPAWN_ERROR_NAMETOOLONG: execv() returned `ENAMETOOLONG`
  52  * @G_SPAWN_ERROR_NOENT: execv() returned `ENOENT`
  53  * @G_SPAWN_ERROR_NOMEM: execv() returned `ENOMEM`
  54  * @G_SPAWN_ERROR_NOTDIR: execv() returned `ENOTDIR`
  55  * @G_SPAWN_ERROR_LOOP: execv() returned `ELOOP`
  56  * @G_SPAWN_ERROR_TXTBUSY: execv() returned `ETXTBUSY`
  57  * @G_SPAWN_ERROR_IO: execv() returned `EIO`
  58  * @G_SPAWN_ERROR_NFILE: execv() returned `ENFILE`
  59  * @G_SPAWN_ERROR_MFILE: execv() returned `EMFILE`
  60  * @G_SPAWN_ERROR_INVAL: execv() returned `EINVAL`
  61  * @G_SPAWN_ERROR_ISDIR: execv() returned `EISDIR`
  62  * @G_SPAWN_ERROR_LIBBAD: execv() returned `ELIBBAD`
  63  * @G_SPAWN_ERROR_FAILED: Some other fatal failure,
  64  *   `error->message` should explain.
  65  *
  66  * Error codes returned by spawning processes.
  67  */
  68 typedef enum
  69 {
  70   G_SPAWN_ERROR_FORK,   /* fork failed due to lack of memory */
  71   G_SPAWN_ERROR_READ,   /* read or select on pipes failed */
  72   G_SPAWN_ERROR_CHDIR,  /* changing to working dir failed */
  73   G_SPAWN_ERROR_ACCES,  /* execv() returned EACCES */
  74   G_SPAWN_ERROR_PERM,   /* execv() returned EPERM */
  75   G_SPAWN_ERROR_TOO_BIG,/* execv() returned E2BIG */
  76 #ifndef G_DISABLE_DEPRECATED
  77   G_SPAWN_ERROR_2BIG = G_SPAWN_ERROR_TOO_BIG,
  78 #endif
  79   G_SPAWN_ERROR_NOEXEC, /* execv() returned ENOEXEC */
  80   G_SPAWN_ERROR_NAMETOOLONG, /* ""  "" ENAMETOOLONG */
  81   G_SPAWN_ERROR_NOENT,       /* ""  "" ENOENT */
  82   G_SPAWN_ERROR_NOMEM,       /* ""  "" ENOMEM */
  83   G_SPAWN_ERROR_NOTDIR,      /* ""  "" ENOTDIR */
  84   G_SPAWN_ERROR_LOOP,        /* ""  "" ELOOP   */
  85   G_SPAWN_ERROR_TXTBUSY,     /* ""  "" ETXTBUSY */
  86   G_SPAWN_ERROR_IO,          /* ""  "" EIO */
  87   G_SPAWN_ERROR_NFILE,       /* ""  "" ENFILE */
  88   G_SPAWN_ERROR_MFILE,       /* ""  "" EMFLE */
  89   G_SPAWN_ERROR_INVAL,       /* ""  "" EINVAL */
  90   G_SPAWN_ERROR_ISDIR,       /* ""  "" EISDIR */
  91   G_SPAWN_ERROR_LIBBAD,      /* ""  "" ELIBBAD */
  92   G_SPAWN_ERROR_FAILED       /* other fatal failure, error->message
  93                               * should explain
  94                               */
  95 } GSpawnError;
  96
  97 /**
  98  * G_SPAWN_EXIT_ERROR:
  99  *
 100  * Error domain used by g_spawn_check_exit_status().  The code
 101  * will be the program exit code.
 102  */
 103 #define G_SPAWN_EXIT_ERROR g_spawn_exit_error_quark ()
 104
 105 /**
 106  * GSpawnChildSetupFunc:
 107  * @user_data: user data to pass to the function.
 108  *
 109  * Specifies the type of the setup function passed to g_spawn_async(),
 110  * g_spawn_sync() and g_spawn_async_with_pipes(), which can, in very
 111  * limited ways, be used to affect the child's execution.
 112  *
 113  * On POSIX platforms, the function is called in the child after GLib
 114  * has performed all the setup it plans to perform, but before calling
 115  * exec(). Actions taken in this function will only affect the child,
 116  * not the parent.
 117  *
 118  * On Windows, the function is called in the parent. Its usefulness on
 119  * Windows is thus questionable. In many cases executing the child setup
 120  * function in the parent can have ill effects, and you should be very
 121  * careful when porting software to Windows that uses child setup
 122  * functions.
 123  *
 124  * However, even on POSIX, you are extremely limited in what you can
 125  * safely do from a #GSpawnChildSetupFunc, because any mutexes that were
 126  * held by other threads in the parent process at the time of the fork()
 127  * will still be locked in the child process, and they will never be
 128  * unlocked (since the threads that held them don't exist in the child).
 129  * POSIX allows only async-signal-safe functions (see signal(7)) to be
 130  * called in the child between fork() and exec(), which drastically limits
 131  * the usefulness of child setup functions.
 132  *
 133  * In particular, it is not safe to call any function which may
 134  * call malloc(), which includes POSIX functions such as setenv().
 135  * If you need to set up the child environment differently from
 136  * the parent, you should use g_get_environ(), g_environ_setenv(),
 137  * and g_environ_unsetenv(), and then pass the complete environment
 138  * list to the `g_spawn...` function.
 139  */
 140 typedef void (* GSpawnChildSetupFunc) (gpointer user_data);
 141
 142 /**
 143  * GSpawnFlags:
 144  * @G_SPAWN_DEFAULT: no flags, default behaviour
 145  * @G_SPAWN_LEAVE_DESCRIPTORS_OPEN: the parent's open file descriptors will
 146  *     be inherited by the child; otherwise all descriptors except stdin,
 147  *     stdout and stderr will be closed before calling exec() in the child.
 148  * @G_SPAWN_DO_NOT_REAP_CHILD: the child will not be automatically reaped;
 149  *     you must use g_child_watch_add() yourself (or call waitpid() or handle
 150  *     `SIGCHLD` yourself), or the child will become a zombie.
 151  * @G_SPAWN_SEARCH_PATH: `argv[0]` need not be an absolute path, it will be
 152  *     looked for in the user's `PATH`.
 153  * @G_SPAWN_STDOUT_TO_DEV_NULL: the child's standard output will be discarded,
 154  *     instead of going to the same location as the parent's standard output.
 155  * @G_SPAWN_STDERR_TO_DEV_NULL: the child's standard error will be discarded.
 156  * @G_SPAWN_CHILD_INHERITS_STDIN: the child will inherit the parent's standard
 157  *     input (by default, the child's standard input is attached to `/dev/null`).
 158  * @G_SPAWN_FILE_AND_ARGV_ZERO: the first element of `argv` is the file to
 159  *     execute, while the remaining elements are the actual argument vector
 160  *     to pass to the file. Normally g_spawn_async_with_pipes() uses `argv[0]`
 161  *     as the file to execute, and passes all of `argv` to the child.
 162  * @G_SPAWN_SEARCH_PATH_FROM_ENVP: if `argv[0]` is not an abolute path,
 163  *     it will be looked for in the `PATH` from the passed child environment.
 164  *     Since: 2.34
 165  * @G_SPAWN_CLOEXEC_PIPES: create all pipes with the `O_CLOEXEC` flag set.
 166  *     Since: 2.40
 167  *
 168  * Flags passed to g_spawn_sync(), g_spawn_async() and g_spawn_async_with_pipes().
 169  */
 170 typedef enum
 171 {
 172   G_SPAWN_DEFAULT                = 0,
 173   G_SPAWN_LEAVE_DESCRIPTORS_OPEN = 1 << 0,
 174   G_SPAWN_DO_NOT_REAP_CHILD      = 1 << 1,
 175   /* look for argv[0] in the path i.e. use execvp() */
 176   G_SPAWN_SEARCH_PATH            = 1 << 2,
 177   /* Dump output to /dev/null */
 178   G_SPAWN_STDOUT_TO_DEV_NULL     = 1 << 3,
 179   G_SPAWN_STDERR_TO_DEV_NULL     = 1 << 4,
 180   G_SPAWN_CHILD_INHERITS_STDIN   = 1 << 5,
 181   G_SPAWN_FILE_AND_ARGV_ZERO     = 1 << 6,
 182   G_SPAWN_SEARCH_PATH_FROM_ENVP  = 1 << 7,
 183   G_SPAWN_CLOEXEC_PIPES          = 1 << 8
 184 } GSpawnFlags;
 185
 186 GLIB_AVAILABLE_IN_ALL
 187 GQuark g_spawn_error_quark (void);
 188 GLIB_AVAILABLE_IN_ALL
 189 GQuark g_spawn_exit_error_quark (void);
 190
 191 GLIB_AVAILABLE_IN_ALL
 192 gboolean g_spawn_async (const gchar           *working_directory,
 193                         gchar                **argv,
 194                         gchar                **envp,
 195                         GSpawnFlags            flags,
 196                         GSpawnChildSetupFunc   child_setup,
 197                         gpointer               user_data,
 198                         GPid                  *child_pid,
 199                         GError               **error);
 200
 201
 202 /* Opens pipes for non-NULL standard_output, standard_input, standard_error,
 203  * and returns the parent's end of the pipes.
 204  */
 205 GLIB_AVAILABLE_IN_ALL
 206 gboolean g_spawn_async_with_pipes (const gchar          *working_directory,
 207                                    gchar               **argv,
 208                                    gchar               **envp,
 209                                    GSpawnFlags           flags,
 210                                    GSpawnChildSetupFunc  child_setup,
 211                                    gpointer              user_data,
 212                                    GPid                 *child_pid,
 213                                    gint                 *standard_input,
 214                                    gint                 *standard_output,
 215                                    gint                 *standard_error,
 216                                    GError              **error);
 217
 218
 219 /* If standard_output or standard_error are non-NULL, the full
 220  * standard output or error of the command will be placed there.
 221  */
 222
 223 GLIB_AVAILABLE_IN_ALL
 224 gboolean g_spawn_sync         (const gchar          *working_directory,
 225                                gchar               **argv,
 226                                gchar               **envp,
 227                                GSpawnFlags           flags,
 228                                GSpawnChildSetupFunc  child_setup,
 229                                gpointer              user_data,
 230                                gchar               **standard_output,
 231                                gchar               **standard_error,
 232                                gint                 *exit_status,
 233                                GError              **error);
 234
 235 GLIB_AVAILABLE_IN_ALL
 236 gboolean g_spawn_command_line_sync  (const gchar          *command_line,
 237                                      gchar               **standard_output,
 238                                      gchar               **standard_error,
 239                                      gint                 *exit_status,
 240                                      GError              **error);
 241 GLIB_AVAILABLE_IN_ALL
 242 gboolean g_spawn_command_line_async (const gchar          *command_line,
 243                                      GError              **error);
 244
 245 GLIB_AVAILABLE_IN_2_34
 246 gboolean g_spawn_check_exit_status (gint      exit_status,
 247                                     GError  **error);
 248
 249 GLIB_AVAILABLE_IN_ALL
 250 void g_spawn_close_pid (GPid pid);
 251
 252 G_END_DECLS
 253
 254 #endif /* __G_SPAWN_H__ */