X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=glib%2Fgspawn.c;h=3cd43a4e4407059046f2983705c59204b7f938d3;hb=49b59e5ac4428a6a99a85d699c3662f96efc4e9d;hp=0e6106ca19fd9b6d120f780cbfa0c4a6f6f96f0d;hpb=e30bbca6679605487e52e52f810c54a0464b6d37;p=platform%2Fupstream%2Fglib.git diff --git a/glib/gspawn.c b/glib/gspawn.c index 0e6106c..3cd43a4 100644 --- a/glib/gspawn.c +++ b/glib/gspawn.c @@ -59,6 +59,17 @@ * SECTION:spawn * @Short_description: process launching * @Title: Spawning Processes + * + * GLib supports spawning of processes with an API that is more + * convenient than the bare UNIX fork() and exec(). + * + * The g_spawn family of functions has synchronous (g_spawn_sync()) + * and asynchronous variants (g_spawn_async(), g_spawn_async_with_pipes()), + * as well as convenience variants that take a complete shell-like + * commandline (g_spawn_command_line_sync(), g_spawn_command_line_async()). + * + * See #GSubprocess in GIO for a higher-level API that provides + * stream interfaces for communication with child processes. */ @@ -109,19 +120,16 @@ G_DEFINE_QUARK (g-spawn-exit-error-quark, g_spawn_exit_error) * You should call g_spawn_close_pid() on the returned child process * reference when you don't need it any more. * - * - * If you are writing a GTK+ application, and the program you - * are spawning is a graphical application, too, then you may - * want to use gdk_spawn_on_screen() instead to ensure that - * the spawned program opens its windows on the right screen. - * + * If you are writing a GTK+ application, and the program you are + * spawning is a graphical application, too, then you may want to + * use gdk_spawn_on_screen() instead to ensure that the spawned program + * opens its windows on the right screen. * - * Note that the returned @child_pid on Windows is a - * handle to the child process and not its identifier. Process handles - * and process identifiers are different concepts on Windows. - * + * Note that the returned @child_pid on Windows is a handle to the child + * process and not its identifier. Process handles and process identifiers + * are different concepts on Windows. * - * Return value: %TRUE on success, %FALSE if error is set + * Returns: %TRUE on success, %FALSE if error is set **/ gboolean g_spawn_async (const gchar *working_directory, @@ -237,8 +245,8 @@ read_data (GString *str, * function for full details on the other parameters and details on * how these functions work on Windows. * - * Return value: %TRUE on success, %FALSE if an error was set. - **/ + * Returns: %TRUE on success, %FALSE if an error was set + */ gboolean g_spawn_sync (const gchar *working_directory, gchar **argv, @@ -473,18 +481,18 @@ g_spawn_sync (const gchar *working_directory, * * Executes a child program asynchronously (your program will not * block waiting for the child to exit). The child program is - * specified by the only argument that must be provided, @argv. @argv - * should be a %NULL-terminated array of strings, to be passed as the - * argument vector for the child. The first string in @argv is of - * course the name of the program to execute. By default, the name of - * the program must be a full path. If @flags contains the - * %G_SPAWN_SEARCH_PATH flag, the PATH environment variable - * is used to search for the executable. If @flags contains the - * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the PATH variable from - * @envp is used to search for the executable. - * If both the %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP - * flags are set, the PATH variable from @envp takes precedence - * over the environment variable. + * specified by the only argument that must be provided, @argv. + * @argv should be a %NULL-terminated array of strings, to be passed + * as the argument vector for the child. The first string in @argv + * is of course the name of the program to execute. By default, the + * name of the program must be a full path. If @flags contains the + * %G_SPAWN_SEARCH_PATH flag, the `PATH` environment variable is + * used to search for the executable. If @flags contains the + * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the `PATH` variable from + * @envp is used to search for the executable. If both the + * %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP flags + * are set, the `PATH` variable from @envp takes precedence over + * the environment variable. * * If the program name is not a full path and %G_SPAWN_SEARCH_PATH flag is not * used, then the program will be run from the current directory (or @@ -509,21 +517,19 @@ g_spawn_sync (const gchar *working_directory, * level wide character command line passed to the spawned program * using the GetCommandLineW() function. * - * On Windows the low-level child process creation API - * CreateProcess() doesn't use argument vectors, - * but a command line. The C runtime library's - * spawn*() family of functions (which - * g_spawn_async_with_pipes() eventually calls) paste the argument - * vector elements together into a command line, and the C runtime startup code - * does a corresponding reconstruction of an argument vector from the - * command line, to be passed to main(). Complications arise when you have - * argument vector elements that contain spaces of double quotes. The - * spawn*() functions don't do any quoting or - * escaping, but on the other hand the startup code does do unquoting - * and unescaping in order to enable receiving arguments with embedded - * spaces or double quotes. To work around this asymmetry, - * g_spawn_async_with_pipes() will do quoting and escaping on argument - * vector elements that need it before calling the C runtime + * On Windows the low-level child process creation API CreateProcess() + * doesn't use argument vectors, but a command line. The C runtime + * library's spawn*() family of functions (which g_spawn_async_with_pipes() + * eventually calls) paste the argument vector elements together into + * a command line, and the C runtime startup code does a corresponding + * reconstruction of an argument vector from the command line, to be + * passed to main(). Complications arise when you have argument vector + * elements that contain spaces of double quotes. The spawn*() functions + * don't do any quoting or escaping, but on the other hand the startup + * code does do unquoting and unescaping in order to enable receiving + * arguments with embedded spaces or double quotes. To work around this + * asymmetry, g_spawn_async_with_pipes() will do quoting and escaping on + * argument vector elements that need it before calling the C runtime * spawn() function. * * The returned @child_pid on Windows is a handle to the child @@ -531,9 +537,8 @@ g_spawn_sync (const gchar *working_directory, * identifiers are different concepts on Windows. * * @envp is a %NULL-terminated array of strings, where each string - * has the form KEY=VALUE. This will become - * the child's environment. If @envp is %NULL, the child inherits its - * parent's environment. + * has the form `KEY=VALUE`. This will become the child's environment. + * If @envp is %NULL, the child inherits its parent's environment. * * @flags should be the bitwise OR of any flags you want to affect the * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that the @@ -542,22 +547,21 @@ g_spawn_sync (const gchar *working_directory, * call g_spawn_close_pid() on the @child_pid, in order to free * resources which may be associated with the child process. (On Unix, * using a child watch is equivalent to calling waitpid() or handling - * the SIGCHLD signal manually. On Windows, calling g_spawn_close_pid() + * the %SIGCHLD signal manually. On Windows, calling g_spawn_close_pid() * is equivalent to calling CloseHandle() on the process handle returned - * in @child_pid). See g_child_watch_add(). + * in @child_pid). See g_child_watch_add(). * * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file - * descriptors will be inherited by the child; otherwise all - * descriptors except stdin/stdout/stderr will be closed before - * calling exec() in the child. %G_SPAWN_SEARCH_PATH - * means that argv[0] need not be an absolute path, it - * will be looked for in the PATH environment variable. - * %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an absolute path, it - * will be looked for in the PATH variable from @envp. If - * both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP are used, - * the value from @envp takes precedence over the environment. - * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will - * be discarded, instead of going to the same location as the parent's + * descriptors will be inherited by the child; otherwise all descriptors + * except stdin/stdout/stderr will be closed before calling exec() in + * the child. %G_SPAWN_SEARCH_PATH means that @argv[0] need not be an + * absolute path, it will be looked for in the `PATH` environment + * variable. %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an + * absolute path, it will be looked for in the `PATH` variable from + * @envp. If both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP + * are used, the value from @envp takes precedence over the environment. + * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output + * will be discarded, instead of going to the same location as the parent's * standard output. If you use this flag, @standard_output must be %NULL. * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error * will be discarded, instead of going to the same location as the parent's @@ -566,42 +570,40 @@ g_spawn_sync (const gchar *working_directory, * standard input (by default, the child's standard input is attached to * /dev/null). If you use this flag, @standard_input must be %NULL. * %G_SPAWN_FILE_AND_ARGV_ZERO means that 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. + * 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. * * @child_setup and @user_data are a function and user data. On POSIX * platforms, the function is called in the child after GLib has * performed all the setup it plans to perform (including creating - * pipes, closing file descriptors, etc.) but before calling - * exec(). That is, @child_setup is called just - * before calling exec() in the child. Obviously - * actions taken in this function will only affect the child, not the - * parent. + * pipes, closing file descriptors, etc.) but before calling exec(). + * That is, @child_setup is called just before calling exec() in the + * child. Obviously actions taken in this function will only affect + * the child, not the parent. * - * On Windows, there is no separate fork() and exec() - * functionality. Child processes are created and run with a single - * API call, CreateProcess(). There is no sensible thing @child_setup + * On Windows, there is no separate fork() and exec() functionality. + * Child processes are created and run with a single API call, + * CreateProcess(). There is no sensible thing @child_setup * could be used for on Windows so it is ignored and not called. * * If non-%NULL, @child_pid will on Unix be filled with the child's - * process ID. You can use the process ID to send signals to the - * child, or to use g_child_watch_add() (or waitpid()) if you specified the + * process ID. You can use the process ID to send signals to the child, + * or to use g_child_watch_add() (or waitpid()) if you specified the * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be * filled with a handle to the child process only if you specified the * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child * process using the Win32 API, for example wait for its termination - * with the WaitFor*() functions, or examine its - * exit code with GetExitCodeProcess(). You should close the handle - * with CloseHandle() or g_spawn_close_pid() when you no longer need it. + * with the WaitFor*() functions, or examine its exit code with + * GetExitCodeProcess(). You should close the handle with CloseHandle() + * or g_spawn_close_pid() when you no longer need it. * * If non-%NULL, the @standard_input, @standard_output, @standard_error * locations will be filled with file descriptors for writing to the child's * standard input or reading from its standard output or standard error. * The caller of g_spawn_async_with_pipes() must close these file descriptors - * when they are no longer in use. If these parameters are %NULL, the corresponding - * pipe won't be created. + * when they are no longer in use. If these parameters are %NULL, the + * corresponding pipe won't be created. * * If @standard_input is NULL, the child's standard input is attached to * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set. @@ -615,11 +617,11 @@ g_spawn_sync (const gchar *working_directory, * is set. * * @error can be %NULL to ignore errors, or non-%NULL to report errors. - * If an error is set, the function returns %FALSE. Errors - * are reported even if they occur in the child (for example if the - * executable in argv[0] is not found). Typically - * the message field of returned errors should be displayed - * to users. Possible errors are those from the #G_SPAWN_ERROR domain. + * If an error is set, the function returns %FALSE. Errors are reported + * even if they occur in the child (for example if the executable in + * @argv[0] is not found). Typically the `message` field of returned + * errors should be displayed to users. Possible errors are those from + * the #G_SPAWN_ERROR domain. * * If an error occurs, @child_pid, @standard_input, @standard_output, * and @standard_error will not be filled with valid values. @@ -627,15 +629,13 @@ g_spawn_sync (const gchar *working_directory, * If @child_pid is not %NULL and an error does not occur then the returned * process reference must be closed using g_spawn_close_pid(). * - * * If you are writing a GTK+ application, and the program you * are spawning is a graphical application, too, then you may * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that * the spawned program opens its windows on the right screen. - * * - * Return value: %TRUE on success, %FALSE if an error was set - **/ + * Returns: %TRUE on success, %FALSE if an error was set + */ gboolean g_spawn_async_with_pipes (const gchar *working_directory, gchar **argv, @@ -710,7 +710,7 @@ g_spawn_async_with_pipes (const gchar *working_directory, * separator. You need to enclose such paths with single quotes, like * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'". * - * Return value: %TRUE on success, %FALSE if an error was set + * Returns: %TRUE on success, %FALSE if an error was set **/ gboolean g_spawn_command_line_sync (const gchar *command_line, @@ -759,7 +759,7 @@ g_spawn_command_line_sync (const gchar *command_line, * * The same concerns on Windows apply as for g_spawn_command_line_sync(). * - * Return value: %TRUE on success, %FALSE if error is set. + * Returns: %TRUE on success, %FALSE if error is set **/ gboolean g_spawn_command_line_async (const gchar *command_line, @@ -798,25 +798,23 @@ g_spawn_command_line_async (const gchar *command_line, * * The g_spawn_sync() and g_child_watch_add() family of APIs return an * exit status for subprocesses encoded in a platform-specific way. - * On Unix, this is guaranteed to be in the same format - * waitpid(2) returns, and on Windows it is - * guaranteed to be the result of - * GetExitCodeProcess(). Prior to the introduction - * of this function in GLib 2.34, interpreting @exit_status required - * use of platform-specific APIs, which is problematic for software - * using GLib as a cross-platform layer. + * On Unix, this is guaranteed to be in the same format waitpid() returns, + * and on Windows it is guaranteed to be the result of GetExitCodeProcess(). + * + * Prior to the introduction of this function in GLib 2.34, interpreting + * @exit_status required use of platform-specific APIs, which is problematic + * for software using GLib as a cross-platform layer. * * Additionally, many programs simply want to determine whether or not * the child exited successfully, and either propagate a #GError or - * print a message to standard error. In that common case, this - * function can be used. Note that the error message in @error will - * contain human-readable information about the exit status. + * print a message to standard error. In that common case, this function + * can be used. Note that the error message in @error will contain + * human-readable information about the exit status. * - * The domain and code of @error - * have special semantics in the case where the process has an "exit - * code", as opposed to being killed by a signal. On Unix, this - * happens if WIFEXITED would be true of - * @exit_status. On Windows, it is always the case. + * The @domain and @code of @error have special semantics in the case + * where the process has an "exit code", as opposed to being killed by + * a signal. On Unix, this happens if WIFEXITED() would be true of + * @exit_status. On Windows, it is always the case. * * The special semantics are that the actual exit code will be the * code set in @error, and the domain will be %G_SPAWN_EXIT_ERROR. @@ -828,12 +826,13 @@ g_spawn_command_line_async (const gchar *command_line, * * This function just offers convenience; you can of course also check * the available platform via a macro such as %G_OS_UNIX, and use - * WIFEXITED() and WEXITSTATUS() - * on @exit_status directly. Do not attempt to scan or parse the - * error message string; it may be translated and/or change in future - * versions of GLib. + * WIFEXITED() and WEXITSTATUS() on @exit_status directly. Do not attempt + * to scan or parse the error message string; it may be translated and/or + * change in future versions of GLib. + * + * Returns: %TRUE if child exited successfully, %FALSE otherwise (and + * @error will be set) * - * Returns: %TRUE if child exited successfully, %FALSE otherwise (and @error will be set) * Since: 2.34 */ gboolean