External command: Cutter Reference Manual

## External command External command — Convenience API for using external command. |

## Functions

GQuark | gcut_process_error_quark ()
GCutProcess * | gcut_process_new ()
GCutProcess * | gcut_process_new_command_line ()
GCutProcess * | gcut_process_new_va_list ()
GCutProcess * | gcut_process_new_argv ()
GCutProcess * | gcut_process_new_strings ()
GCutProcess * | gcut_process_new_array ()
void | gcut_process_set_flags ()
GSpawnFlags | gcut_process_get_flags ()
void | gcut_process_set_env ()
gchar ** | gcut_process_get_env ()
gboolean | gcut_process_run ()
GPid | gcut_process_get_pid ()
gint | gcut_process_wait ()
gboolean | gcut_process_kill ()
gboolean | gcut_process_write ()
GIOStatus | gcut_process_flush ()
GString * | gcut_process_get_output_string ()
GString * | gcut_process_get_error_string ()
GIOChannel * | gcut_process_get_input_channel ()
GIOChannel * | gcut_process_get_output_channel ()
GIOChannel * | gcut_process_get_error_channel ()
GInputStream * | gcut_process_get_output_stream ()
GInputStream * | gcut_process_get_error_stream ()
guint | gcut_process_get_forced_termination_wait_time ()
void | gcut_process_set_forced_termination_wait_time ()
GCutEventLoop * | gcut_process_get_event_loop ()
void | gcut_process_set_event_loop ()

## Properties

gpointer | command | Read / Write

## Signals

void | error | Run Last
void | error-received | Run Last
void | output-received | Run Last
void | reaped | Run Last

## Types and Values

#define | GCUT_PROCESS_ERROR
enum | GCutProcessError

## Object Hierarchy

        GObject
        ╰── GCutProcess

## Description

GCutProcess encapsulates external command execution, communication and termination. GCutProcess reports an error as GError. It can be asserted easily by `gcut_assert_error()`.

External command is specified to constructor like `gcut_process_new()`, `gcut_process_new_strings()` and so on. External command isn't run at the time. `gcut_process_run()` runs specified external command.

Standard/Error outputs of external command are passed by “output-received”/“error-received” signals or GIOChannel returned by `gcut_process_get_output()`/`gcut_process_get_error()`. `gcut_process_write()` writes a chunk to standard input of external command.

To wait external command finished, `gcut_process_wait()` can be used. It accepts timeout to avoid infinite waiting.

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    static GString *output_string;
    static GCutProcess *process;

    void
    cut_setup (void)
    {
        output_string = g_string_new(NULL);
        process = NULL;
    }

    void
    cut_teardown (void)
    {
        if (output_string)
            g_string_free(output_string, TRUE);
        if (process)
            g_object_unref(process);
    }

    static void
    cb_output_received (GCutProcess *process, const gchar *chunk, gsize size,
                        gpointer user_data)
    {
        g_string_append_len(output_string, chunk, size);
    }

    void
    test_echo (void)
    {
        GError *error = NULL;

        process = gcut_process_new("echo", "XXX", NULL);
        g_signal_connect(process, "receive-output",
                         G_CALLBACK(cb_output_received), NULL);

        gcut_process_run(process, &error);
        gcut_assert_error(error);

        gcut_process_wait(process, 1000, &error);
        gcut_assert_error(error);
        cut_assert_equal_string("XXX\n", output_string->str);
    }

## Functions

### gcut_process_error_quark ()

    GQuark
    gcut_process_error_quark (void);

### gcut_process_new ()

    GCutProcess *
    gcut_process_new (const gchar *command,
                      ...);

Creates a new GCutProcess object that runs `command` .

#### Parameters

command | the external command name to be ran |
... | the arguments for `command` |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_new_command_line ()

    GCutProcess *
    gcut_process_new_command_line (const gchar *command_line);

Creates a new GCutProcess object that runs `command_line` .

#### Parameters

command_line | a command line |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_new_va_list ()

    GCutProcess *
    gcut_process_new_va_list (const gchar *command,
                              va_list args);

Creates a new GCutProcess object that runs `command` .

#### Parameters

command | the external command name to be ran |
args | arguments for `command` |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_new_argv ()

    GCutProcess *
    gcut_process_new_argv (gint argc,
                           gchar **argv);

Creates a new GCutProcess object that runs `command` .

#### Parameters

argc | the number of elements of `argv` |
argv | the external command name to be ran and arguments of it. |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_new_strings ()

    GCutProcess *
    gcut_process_new_strings (const gchar **command);

Creates a new GCutProcess object that runs `command` .

#### Parameters

command | the external command name to be ran and arguments of it. `NULL`-terminated. |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_new_array ()

    GCutProcess *
    gcut_process_new_array (GArray *command);

Creates a new GCutProcess object that runs `command` .

#### Parameters

command | the external command name to be ran and arguments of it. The GArray should be zero-terminated. |

#### Returns

a new GCutProcess.

Since: 1.1.5

### gcut_process_set_flags ()

    void
    gcut_process_set_flags (GCutProcess *process,
                            GSpawnFlags flags);

Sets `flags` for spawning.

#### Parameters

process | a GCutProcess |
flags | the flags to be passed to `g_spawn_async_with_pipes()`. |

Since: 1.1.5

### gcut_process_get_flags ()

    GSpawnFlags
    gcut_process_get_flags (GCutProcess *process);

Gets `flags` for spawning.

#### Parameters

process | a GCutProcess |

#### Returns

the flags for spawning.

Since: 1.1.5

### gcut_process_set_env ()

    void
    gcut_process_set_env (GCutProcess *process,
                          const gchar *name,
                          ...);

Sets environment variable for external command.

#### Parameters

process | a GCutProcess |
name | the first environment name. |
... | the value of `name` , followed by name and value pairs. `NULL`-terminated. |

Since: 1.1.5

### gcut_process_get_env ()

    gchar **
    gcut_process_get_env (GCutProcess *process);

Gets environment variable for external command.

#### Parameters

process | a GCutProcess |

#### Returns

a newly-allocated `NULL`-terminated environment variables. ("NAME1=VALUE1", "NAME2=VALUE2", ..., `NULL`) It should be freed by `g_strfreev()` when no longer needed.

Since: 1.1.5

### gcut_process_run ()

    gboolean
    gcut_process_run (GCutProcess *process,
                      GError **error);

Runs a new external process.

#### Parameters

process | a GCutProcess |
error | return location for an error, or `NULL` |

#### Returns

`TRUE` on success, otherwise `FALSE`

Since: 1.1.5

### gcut_process_get_pid ()

    GPid
    gcut_process_get_pid (GCutProcess *process);

Gets the process ID of running external process. If external process isn't running, 0 is returned.

#### Parameters

process | a GCutProcess |

#### Returns

the process ID of running external process if external process is running, otherwise 0.

Since: 1.1.5

### gcut_process_wait ()

    gint
    gcut_process_wait (GCutProcess *process,
                       guint timeout,
                       GError **error);

Waits running external process is finished while `timeout` milliseconds. If external process isn't finished while `timeout` milliseconds, `GCUT_PROCESS_ERROR_TIMEOUT` error is set and -1 is returned. If external process isn't running, `GCUT_PROCESS_ERROR_NOT_RUNNING` error is set and -1 is returned.

#### Parameters

process | a GCutProcess |
timeout | the timeout period in milliseconds |
error | return location for an error, or `NULL` |

#### Returns

an exit status of external process on success, otherwise -1.

Since: 1.1.5

### gcut_process_kill ()

    gboolean
    gcut_process_kill (GCutProcess *process,
                       gint signal_number,
                       GError **error);

Sends `signal_number` signal to external process.

#### Parameters

process | a GCutProcess |
signal_number | the signal number to be sent to external process |
error | return location for an error, or `NULL` |

#### Returns

`TRUE` on success, otherwise `FALSE`

Since: 1.1.5

### gcut_process_write ()

    gboolean
    gcut_process_write (GCutProcess *process,
                        const gchar *chunk,
                        gsize size,
                        GError **error);

Writes `chunk` to external process's standard input.

#### Parameters

process | a GCutProcess |
chunk | the data to be wrote |
size | the size of `chunk` |
error | return location for an error, or `NULL` |

#### Returns

`TRUE` on success, otherwise `FALSE`

Since: 1.1.5

### gcut_process_flush ()

    GIOStatus
    gcut_process_flush (GCutProcess *process,
                        GError **error);

Flush buffered external process's standard input.

#### Parameters

process | a GCutProcess |
error | return location for an error, or `NULL` |

#### Returns

the status of the operation: One of `G_IO_STATUS_NORMAL`, `G_IO_STATUS_AGAIN`, or `G_IO_STATUS_ERROR`.

Since: 1.1.5

### gcut_process_get_output_string ()

    GString *
    gcut_process_get_output_string (GCutProcess *process);

#### Parameters

process | a GCutProcess |

#### Returns

a GString that has all result of standard output of external process.

Since: 1.1.5

### gcut_process_get_error_string ()

    GString *
    gcut_process_get_error_string (GCutProcess *process);

#### Parameters

process | a GCutProcess |

#### Returns

a GString that has all result of standard error of external process.

Since: 1.1.5

### gcut_process_get_input_channel ()

    GIOChannel *
    gcut_process_get_input_channel (GCutProcess *process);

Gets a GIOChannel connected with standard input of external process.

#### Parameters

process | a GCutProcess |

#### Returns

a GIOChannel if external process is running, otherwise `NULL`.

Since: 1.1.5

### gcut_process_get_output_channel ()

    GIOChannel *
    gcut_process_get_output_channel (GCutProcess *process);

Gets a GIOChannel connected with standard output of external process.

#### Parameters

process | a GCutProcess |

#### Returns

a GIOChannel if external process is running, otherwise `NULL`.

Since: 1.1.5

### gcut_process_get_error_channel ()

    GIOChannel *
    gcut_process_get_error_channel (GCutProcess *process);

Gets a GIOChannel connected with standard error output of external process.

#### Parameters

process | a GCutProcess |

#### Returns

a GIOChannel if external process is running, otherwise `NULL`.

Since: 1.1.5

### gcut_process_get_output_stream ()

    GInputStream *
    gcut_process_get_output_stream (GCutProcess *process);

Gets a GInputStream connected with standard output of external process.

#### Parameters

process | a GCutProcess |

#### Returns

a GInputStream if external process is running, otherwise `NULL`.

Since: 1.1.5

### gcut_process_get_error_stream ()

    GInputStream *
    gcut_process_get_error_stream (GCutProcess *process);

Gets a GInputStream connected with standard error output of external process.

#### Parameters

process | a GCutProcess |

#### Returns

a GInputStream if external process is running, otherwise `NULL`.

Since: 1.1.5

### gcut_process_get_forced_termination_wait_time ()

    guint
    gcut_process_get_forced_termination_wait_time
                                   (GCutProcess *process);

Gets a wait time in milliseconds for forced termination on dispose.

#### Parameters

process | a GCutProcess |

#### Returns

a timeout value for waiting forced terminated external command on dispose.

Since: 1.1.5

### gcut_process_set_forced_termination_wait_time ()

    void
    gcut_process_set_forced_termination_wait_time
                                   (GCutProcess *process,
                                    guint timeout);

Sets a wait time in milliseconds for forced termination on dispose. If `timeout` is 0, it doesn't wait termination of external process. The default value is 10.

#### Parameters

process | a GCutProcess |
timeout | the timeout value in milliseconds |

Since: 1.1.5

### gcut_process_get_event_loop ()

    GCutEventLoop *
    gcut_process_get_event_loop (GCutProcess *process);

Gets a event loop using by the `process` .

#### Parameters

process | a GCutProcess |

#### Returns

a GCutEventLoop.

Since: 1.1.6

### gcut_process_set_event_loop ()

    void
    gcut_process_set_event_loop (GCutProcess *process,
                                 GCutEventLoop *loop);

Sets a event loop for the `process` . If `loop` is `NULL`, the default GLib event loop will be used.

#### Parameters

process | a GCutProcess |
loop | the event loop or `NULL` |

Since: 1.1.6

## Types and Values

### GCUT_PROCESS_ERROR

    #define GCUT_PROCESS_ERROR           (gcut_process_error_quark())

### enum GCutProcessError

Error codes returned by GCutProcess related operations.

#### Members

GCUT_PROCESS_ERROR_COMMAND_LINE | Command line related error. |
GCUT_PROCESS_ERROR_IO_ERROR | IO error. |
GCUT_PROCESS_ERROR_ALREADY_RUNNING | External command is already running. |
GCUT_PROCESS_ERROR_NOT_RUNNING | External command isn't running. |
GCUT_PROCESS_ERROR_INVALID_OBJECT | Invalid GCutProcess object is passed. |
GCUT_PROCESS_ERROR_INVALID_SIGNAL | Invalid signal is passed. |
GCUT_PROCESS_ERROR_PERMISSION_DENIED | Permission denied. |
GCUT_PROCESS_ERROR_TIMEOUT | Timeout. |

Since: 1.1.5

## Property Details

### The `“command”` property

      “command”                  gpointer

The command to be ran by the process.

Owner: GCutProcess

Flags: Read / Write

## Signal Details

### The `“error”` signal

    void
    user_function (GCutProcess *process,
                   gpointer     error,
                   gpointer     user_data)

It is emitted each time an external process causes an error. (e.g. IO error)

#### Parameters

process | the object which received the signal. |
error | the error of an external process. (`GError`) |
user_data | user data set when the signal handler was connected. |

Flags: Run Last

Since: 1.1.5

### The `“error-received”` signal

    void
    user_function (GCutProcess *process,
                   char        *chunk,
                   guint64      size,
                   gpointer     user_data)

It is emitted each time an external process outputs something to its standard error output and it is read.

Note that you need to run `GCutEventLoop` by `gcut_event_loop_run()` or `gcut_event_loop_iterate()` for detecting an external process's output is readable.

#### Parameters

process | the object which received the signal. |
chunk | the chunk read from an external process's standard error output. |
size | the size of `chunk` . (`gsize`) |
user_data | user data set when the signal handler was connected. |

Flags: Run Last

Since: 1.1.5

### The `“output-received”` signal

    void
    user_function (GCutProcess *process,
                   char        *chunk,
                   guint64      size,
                   gpointer     user_data)

It is emitted each time an external process outputs something to its standard output and it is read.

Note that you need to run `GCutEventLoop` by `gcut_event_loop_run()` or `gcut_event_loop_iterate()` for detecting an external process's output is readable.

#### Parameters

process | the object which received the signal. |
chunk | the chunk read from an external process's standard output. |
size | the size of `chunk` . (`gsize`) |
user_data | user data set when the signal handler was connected. |

Flags: Run Last

Since: 1.1.5

### The `“reaped”` signal

    void
    user_function (GCutProcess *process,
                   int          status,
                   gpointer     user_data)

It is emitted when an external process is exited.

Note that you need to run `GCutEventLoop` by `gcut_event_loop_run()` or `gcut_event_loop_iterate()` for detecting an external process is exited.

#### Parameters

process | the object which received the signal. |
status | the exit status of an external process. |
user_data | user data set when the signal handler was connected. |

Flags: Run Last

Since: 1.1.5