glib/gspawn.h

   1 /* gspawn.h - Process launching
   2  *
   3  *  Copyright 2000 Red Hat, Inc.
   4  *
   5  * GLib is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public License as
   7  * published by the Free Software Foundation; either version 2 of the
   8  * License, or (at your option) any later version.
   9  *
  10  * GLib 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
  16  * License along with GLib; see the file COPYING.LIB.  If not, write
  17  * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20
  21 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  22 #error "Only <glib.h> can be included directly."
  23 #endif
  24
  25 #ifndef __G_SPAWN_H__
  26 #define __G_SPAWN_H__
  27
  28 #include <glib/gerror.h>
  29
  30 G_BEGIN_DECLS
  31
  32
  33 /* I'm not sure I remember our proposed naming convention here. */
  34 /**
  35  * G_SPAWN_ERROR:
  36  *
  37  * Error domain for spawning processes. Errors in this domain will
  38  * be from the #GSpawnError enumeration. See #GError for information on
  39  * error domains.
  40  */
  41 #define G_SPAWN_ERROR g_spawn_error_quark ()
  42
  43 /**
  44  * GSpawnError:
  45  * @G_SPAWN_ERROR_FORK: Fork failed due to lack of memory.
  46  * @G_SPAWN_ERROR_READ: Read or select on pipes failed.
  47  * @G_SPAWN_ERROR_CHDIR: Changing to working directory failed.
  48  * @G_SPAWN_ERROR_ACCES: execv() returned <literal>EACCES</literal>
  49  * @G_SPAWN_ERROR_PERM: execv() returned <literal>EPERM</literal>
  50  * @G_SPAWN_ERROR_2BIG: execv() returned <literal>E2BIG</literal>
  51  * @G_SPAWN_ERROR_NOEXEC: execv() returned <literal>ENOEXEC</literal>
  52  * @G_SPAWN_ERROR_NAMETOOLONG: execv() returned <literal>ENAMETOOLONG</literal>
  53  * @G_SPAWN_ERROR_NOENT: execv() returned <literal>ENOENT</literal>
  54  * @G_SPAWN_ERROR_NOMEM: execv() returned <literal>ENOMEM</literal>
  55  * @G_SPAWN_ERROR_NOTDIR: execv() returned <literal>ENOTDIR</literal>
  56  * @G_SPAWN_ERROR_LOOP: execv() returned <literal>ELOOP</literal>
  57  * @G_SPAWN_ERROR_TXTBUSY: execv() returned <literal>ETXTBUSY</literal>
  58  * @G_SPAWN_ERROR_IO: execv() returned <literal>EIO</literal>
  59  * @G_SPAWN_ERROR_NFILE: execv() returned <literal>ENFILE</literal>
  60  * @G_SPAWN_ERROR_MFILE: execv() returned <literal>EMFILE</literal>
  61  * @G_SPAWN_ERROR_INVAL: execv() returned <literal>EINVAL</literal>
  62  * @G_SPAWN_ERROR_ISDIR: execv() returned <literal>EISDIR</literal>
  63  * @G_SPAWN_ERROR_LIBBAD: execv() returned <literal>ELIBBAD</literal>
  64  * @G_SPAWN_ERROR_FAILED: Some other fatal failure,
  65  *   <literal>error-&gt;message</literal> should explain.
  66  *
  67  * Error codes returned by spawning processes.
  68  */
  69 typedef enum
  70 {
  71   G_SPAWN_ERROR_FORK,   /* fork failed due to lack of memory */
  72   G_SPAWN_ERROR_READ,   /* read or select on pipes failed */
  73   G_SPAWN_ERROR_CHDIR,  /* changing to working dir failed */
  74   G_SPAWN_ERROR_ACCES,  /* execv() returned EACCES */
  75   G_SPAWN_ERROR_PERM,   /* execv() returned EPERM */
  76   G_SPAWN_ERROR_2BIG,   /* execv() returned E2BIG */
  77   G_SPAWN_ERROR_NOEXEC, /* execv() returned ENOEXEC */
  78   G_SPAWN_ERROR_NAMETOOLONG, /* ""  "" ENAMETOOLONG */
  79   G_SPAWN_ERROR_NOENT,       /* ""  "" ENOENT */
  80   G_SPAWN_ERROR_NOMEM,       /* ""  "" ENOMEM */
  81   G_SPAWN_ERROR_NOTDIR,      /* ""  "" ENOTDIR */
  82   G_SPAWN_ERROR_LOOP,        /* ""  "" ELOOP   */
  83   G_SPAWN_ERROR_TXTBUSY,     /* ""  "" ETXTBUSY */
  84   G_SPAWN_ERROR_IO,          /* ""  "" EIO */
  85   G_SPAWN_ERROR_NFILE,       /* ""  "" ENFILE */
  86   G_SPAWN_ERROR_MFILE,       /* ""  "" EMFLE */
  87   G_SPAWN_ERROR_INVAL,       /* ""  "" EINVAL */
  88   G_SPAWN_ERROR_ISDIR,       /* ""  "" EISDIR */
  89   G_SPAWN_ERROR_LIBBAD,      /* ""  "" ELIBBAD */
  90   G_SPAWN_ERROR_FAILED       /* other fatal failure, error->message
  91                               * should explain
  92                               */
  93 } GSpawnError;
  94
  95 /**
  96  * GSpawnChildSetupFunc:
  97  * @user_data: user data to pass to the function.
  98  *
  99  * Specifies the type of the setup function passed to g_spawn_async(),
 100  * g_spawn_sync() and g_spawn_async_with_pipes(), which can, in very
 101  * limited ways, be used to affect the child's execution.
 102  *
 103  * On POSIX platforms, the function is called in the child after GLib
 104  * has performed all the setup it plans to perform, but before calling
 105  * exec(). Actions taken in this function will only affect the child,
 106  * not the parent.
 107  *
 108  * On Windows, the function is called in the parent. Its usefulness on
 109  * Windows is thus questionable. In many cases executing the child setup
 110  * function in the parent can have ill effects, and you should be very
 111  * careful when porting software to Windows that uses child setup
 112  * functions.
 113  *
 114  * However, even on POSIX, you are extremely limited in what you can
 115  * safely do from a #GSpawnChildSetupFunc, because any mutexes that
 116  * were held by other threads in the parent process at the time of the
 117  * fork() will still be locked in the child process, and they will
 118  * never be unlocked (since the threads that held them don't exist in
 119  * the child). POSIX allows only async-signal-safe functions (see
 120  * <citerefentry><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>)
 121  * to be called in the child between fork() and exec(), which
 122  * drastically limits the usefulness of child setup functions.
 123  *
 124  * In particular, it is not safe to call any function which may
 125  * call malloc(), which includes POSIX functions such as setenv().
 126  * If you need to set up the child environment differently from
 127  * the parent, you should use g_get_environ(), g_environ_setenv(),
 128  * and g_environ_unsetenv(), and then pass the complete environment
 129  * list to the <literal>g_spawn...</literal> function.
 130  */
 131 typedef void (* GSpawnChildSetupFunc) (gpointer user_data);
 132
 133 /**
 134  * GSpawnFlags:
 135  * @G_SPAWN_LEAVE_DESCRIPTORS_OPEN: the parent's open file descriptors will be
 136  *   inherited by the child; otherwise all descriptors except stdin/stdout/stderr
 137  *   will be closed before calling exec() in the child.
 138  * @G_SPAWN_DO_NOT_REAP_CHILD: the child will not be automatically reaped; you
 139  *   must use g_child_watch_add() yourself (or call waitpid()
 140  *   or handle <literal>SIGCHLD</literal> yourself), or the child will become a zombie.
 141  * @G_SPAWN_SEARCH_PATH: <literal>argv[0]</literal> need not be an absolute path,
 142  *   it will be looked for in the user's <envar>PATH</envar>.
 143  * @G_SPAWN_STDOUT_TO_DEV_NULL: the child's standard output will be discarded,
 144  *   instead of going to the same location as the parent's standard output.
 145  * @G_SPAWN_STDERR_TO_DEV_NULL: the child's standard error will be discarded.
 146  * @G_SPAWN_CHILD_INHERITS_STDIN: the child will inherit the parent's standard
 147  *   input (by default, the child's standard input is attached to
 148  *   <filename>/dev/null</filename>).
 149  * @G_SPAWN_FILE_AND_ARGV_ZERO: the first element of <literal>argv</literal> is
 150  *   the file to execute, while the remaining elements are the actual argument
 151  *   vector to pass to the file. Normally g_spawn_async_with_pipes() uses
 152  *   <literal>argv[0]</literal> as the file to execute, and passes all of
 153  *   <literal>argv</literal> to the child.
 154  *
 155  * Flags passed to g_spawn_sync(), g_spawn_async() and g_spawn_async_with_pipes().
 156  */
 157 typedef enum
 158 {
 159   G_SPAWN_LEAVE_DESCRIPTORS_OPEN = 1 << 0,
 160   G_SPAWN_DO_NOT_REAP_CHILD      = 1 << 1,
 161   /* look for argv[0] in the path i.e. use execvp() */
 162   G_SPAWN_SEARCH_PATH            = 1 << 2,
 163   /* Dump output to /dev/null */
 164   G_SPAWN_STDOUT_TO_DEV_NULL     = 1 << 3,
 165   G_SPAWN_STDERR_TO_DEV_NULL     = 1 << 4,
 166   G_SPAWN_CHILD_INHERITS_STDIN   = 1 << 5,
 167   G_SPAWN_FILE_AND_ARGV_ZERO     = 1 << 6
 168 } GSpawnFlags;
 169
 170 GQuark g_spawn_error_quark (void);
 171
 172 #ifndef __GTK_DOC_IGNORE__
 173 #ifdef G_OS_WIN32
 174 #define g_spawn_async g_spawn_async_utf8
 175 #define g_spawn_async_with_pipes g_spawn_async_with_pipes_utf8
 176 #define g_spawn_sync g_spawn_sync_utf8
 177 #define g_spawn_command_line_sync g_spawn_command_line_sync_utf8
 178 #define g_spawn_command_line_async g_spawn_command_line_async_utf8
 179 #endif
 180 #endif
 181
 182 gboolean g_spawn_async (const gchar           *working_directory,
 183                         gchar                **argv,
 184                         gchar                **envp,
 185                         GSpawnFlags            flags,
 186                         GSpawnChildSetupFunc   child_setup,
 187                         gpointer               user_data,
 188                         GPid                  *child_pid,
 189                         GError               **error);
 190
 191
 192 /* Opens pipes for non-NULL standard_output, standard_input, standard_error,
 193  * and returns the parent's end of the pipes.
 194  */
 195 gboolean g_spawn_async_with_pipes (const gchar          *working_directory,
 196                                    gchar               **argv,
 197                                    gchar               **envp,
 198                                    GSpawnFlags           flags,
 199                                    GSpawnChildSetupFunc  child_setup,
 200                                    gpointer              user_data,
 201                                    GPid                 *child_pid,
 202                                    gint                 *standard_input,
 203                                    gint                 *standard_output,
 204                                    gint                 *standard_error,
 205                                    GError              **error);
 206
 207
 208 /* If standard_output or standard_error are non-NULL, the full
 209  * standard output or error of the command will be placed there.
 210  */
 211
 212 gboolean g_spawn_sync         (const gchar          *working_directory,
 213                                gchar               **argv,
 214                                gchar               **envp,
 215                                GSpawnFlags           flags,
 216                                GSpawnChildSetupFunc  child_setup,
 217                                gpointer              user_data,
 218                                gchar               **standard_output,
 219                                gchar               **standard_error,
 220                                gint                 *exit_status,
 221                                GError              **error);
 222
 223 gboolean g_spawn_command_line_sync  (const gchar          *command_line,
 224                                      gchar               **standard_output,
 225                                      gchar               **standard_error,
 226                                      gint                 *exit_status,
 227                                      GError              **error);
 228 gboolean g_spawn_command_line_async (const gchar          *command_line,
 229                                      GError              **error);
 230
 231 void g_spawn_close_pid (GPid pid);
 232
 233 G_END_DECLS
 234
 235 #endif /* __G_SPAWN_H__ */