Copyright | Will Thompson and Iñaki García Etxebarria |
---|---|
License | LGPL-2.1 |
Maintainer | Iñaki García Etxebarria |
Safe Haskell | Safe-Inferred |
Language | Haskell2010 |
GApplicationCommandLine
represents a command-line invocation of
an application.
It is created by Application
and emitted
in the Application::commandLine signal and virtual function.
The class contains the list of arguments that the program was invoked with. It is also possible to query if the commandline invocation was local (ie: the current process is running in direct response to the invocation) or remote (ie: some other process forwarded the commandline to this process).
The GApplicationCommandLine
object can provide the argc
and argv
parameters for use with the [structgLib
.OptionContext] command-line parsing API,
with the applicationCommandLineGetArguments
function. See
[gapplication-example-cmdline3.c][gapplication-example-cmdline3]
for an example.
The exit status of the originally-invoked process may be set and messages can be printed to stdout or stderr of that process.
For remote invocation, the originally-invoked process exits when
applicationCommandLineDone
method is called. This method is
also automatically called when the object is disposed.
The main use for GApplicationCommandLine
(and the
Application::commandLine signal) is 'Emacs server' like use cases:
You can set the EDITOR
environment variable to have e.g. git use
your favourite editor to edit commit messages, and if you already
have an instance of the editor running, the editing will happen
in the running instance, instead of opening a new one. An important
aspect of this use case is that the process that gets started by git
does not return until the editing is done.
Normally, the commandline is completely handled in the Application::commandLine handler. The launching instance exits once the signal handler in the primary instance has returned, and the return value of the signal handler becomes the exit status of the launching instance.
c code
static int command_line (GApplication *application, GApplicationCommandLine *cmdline) { gchar **argv; gint argc; gint i; argv = g_application_command_line_get_arguments (cmdline, &argc); g_application_command_line_print (cmdline, "This text is written back\n" "to stdout of the caller\n"); for (i = 0; i < argc; i++) g_print ("argument %d: %s\n", i, argv[i]); g_strfreev (argv); return 0; }
The complete example can be found here: gapplication-example-cmdline.c
In more complicated cases, the handling of the commandline can be split between the launcher and the primary instance.
c code
static gboolean test_local_cmdline (GApplication *application, gchar ***arguments, gint *exit_status) { gint i, j; gchar **argv; argv = *arguments; if (argv[0] == NULL) { *exit_status = 0; return FALSE; } i = 1; while (argv[i]) { if (g_str_has_prefix (argv[i], "--local-")) { g_print ("handling argument %s locally\n", argv[i]); g_free (argv[i]); for (j = i; argv[j]; j++) argv[j] = argv[j + 1]; } else { g_print ("not handling argument %s locally\n", argv[i]); i++; } } *exit_status = 0; return FALSE; } static void test_application_class_init (TestApplicationClass *class) { G_APPLICATION_CLASS (class)->local_command_line = test_local_cmdline; ... }
In this example of split commandline handling, options that start
with --local-
are handled locally, all other options are passed
to the Application::commandLine handler which runs in the primary
instance.
The complete example can be found here: gapplication-example-cmdline2.c
If handling the commandline requires a lot of work, it may be better to defer it.
c code
static gboolean my_cmdline_handler (gpointer data) { GApplicationCommandLine *cmdline = data; // do the heavy lifting in an idle g_application_command_line_set_exit_status (cmdline, 0); g_object_unref (cmdline); // this releases the application return G_SOURCE_REMOVE; } static int command_line (GApplication *application, GApplicationCommandLine *cmdline) { // keep the application running until we are done with this commandline g_application_hold (application); g_object_set_data_full (G_OBJECT (cmdline), "application", application, (GDestroyNotify)g_application_release); g_object_ref (cmdline); g_idle_add (my_cmdline_handler, cmdline); return 0; }
In this example the commandline is not completely handled before
the Application::commandLine handler returns. Instead, we keep
a reference to the GApplicationCommandLine
object and handle it
later (in this example, in an idle). Note that it is necessary to
hold the application until you are done with the commandline.
The complete example can be found here: gapplication-example-cmdline3.c
Synopsis
- newtype ApplicationCommandLine = ApplicationCommandLine (ManagedPtr ApplicationCommandLine)
- class (GObject o, IsDescendantOf ApplicationCommandLine o) => IsApplicationCommandLine o
- toApplicationCommandLine :: (MonadIO m, IsApplicationCommandLine o) => o -> m ApplicationCommandLine
- applicationCommandLineCreateFileForArg :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> [Char] -> m File
- applicationCommandLineDone :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m ()
- applicationCommandLineGetArguments :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m [[Char]]
- applicationCommandLineGetCwd :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m (Maybe [Char])
- applicationCommandLineGetEnviron :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m [[Char]]
- applicationCommandLineGetExitStatus :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m Int32
- applicationCommandLineGetIsRemote :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m Bool
- applicationCommandLineGetOptionsDict :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m VariantDict
- applicationCommandLineGetPlatformData :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m (Maybe GVariant)
- applicationCommandLineGetStdin :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> m (Maybe InputStream)
- applicationCommandLineGetenv :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> [Char] -> m (Maybe Text)
- applicationCommandLinePrintLiteral :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> Text -> m ()
- applicationCommandLinePrinterrLiteral :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> Text -> m ()
- applicationCommandLineSetExitStatus :: (HasCallStack, MonadIO m, IsApplicationCommandLine a) => a -> Int32 -> m ()
- constructApplicationCommandLineArguments :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o)
- getApplicationCommandLineIsRemote :: (MonadIO m, IsApplicationCommandLine o) => o -> m Bool
- constructApplicationCommandLineOptions :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o)
- constructApplicationCommandLinePlatformData :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o)
Exported types
newtype ApplicationCommandLine Source #
Memory-managed wrapper type.
ApplicationCommandLine (ManagedPtr ApplicationCommandLine) |
Instances
class (GObject o, IsDescendantOf ApplicationCommandLine o) => IsApplicationCommandLine o Source #
Type class for types which can be safely cast to ApplicationCommandLine
, for instance with toApplicationCommandLine
.
Instances
(GObject o, IsDescendantOf ApplicationCommandLine o) => IsApplicationCommandLine o Source # | |
Defined in GI.Gio.Objects.ApplicationCommandLine |
toApplicationCommandLine :: (MonadIO m, IsApplicationCommandLine o) => o -> m ApplicationCommandLine Source #
Cast to ApplicationCommandLine
, for types for which this is known to be safe. For general casts, use castTo
.
Methods
Click to display all available methods, including inherited ones
Methods
bindProperty, bindPropertyFull, createFileForArg, done, forceFloating, freezeNotify, getenv, getv, isFloating, notify, notifyByPspec, printLiteral, printerrLiteral, ref, refSink, runDispose, stealData, stealQdata, thawNotify, unref, watchClosure.
Getters
getArguments, getCwd, getData, getEnviron, getExitStatus, getIsRemote, getOptionsDict, getPlatformData, getProperty, getQdata, getStdin.
Setters
createFileForArg
applicationCommandLineCreateFileForArg Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> [Char] |
|
-> m File | Returns: a new |
Creates a File
corresponding to a filename that was given as part
of the invocation of cmdline
.
This differs from fileNewForCommandlineArg
in that it
resolves relative pathnames using the current working directory of
the invoking process rather than the local process.
Since: 2.36
done
applicationCommandLineDone Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m () |
Signals that command line processing is completed.
For remote invocation, it causes the invoking process to terminate.
For local invocation, it does nothing.
This method should be called in the Application::commandLine handler, after the exit status is set and all messages are printed.
After this call, applicationCommandLineSetExitStatus
has no effect.
Subsequent calls to this method are no-ops.
This method is automatically called when the ApplicationCommandLine
object is disposed — so you can omit the call in non-garbage collected
languages.
Since: 2.80
getArguments
applicationCommandLineGetArguments Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m [[Char]] | Returns: the string array containing the arguments (the argv) |
Gets the list of arguments that was passed on the command line.
The strings in the array may contain non-UTF-8 data on UNIX (such as filenames or arguments given in the system locale) but are always in UTF-8 on Windows.
If you wish to use the return value with OptionContext
, you must
use optionContextParseStrv
.
The return value is Nothing
-terminated and should be freed using
strfreev
.
Since: 2.28
getCwd
applicationCommandLineGetCwd Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m (Maybe [Char]) | Returns: the current directory, or |
Gets the working directory of the command line invocation. The string may contain non-utf8 data.
It is possible that the remote application did not send a working
directory, so this may be Nothing
.
The return value should not be modified or freed and is valid for as
long as cmdline
exists.
Since: 2.28
getEnviron
applicationCommandLineGetEnviron Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m [[Char]] | Returns:
the environment strings, or |
Gets the contents of the 'environ' variable of the command line
invocation, as would be returned by getEnviron
, ie as a
Nothing
-terminated list of strings in the form 'NAME=VALUE'.
The strings may contain non-utf8 data.
The remote application usually does not send an environment. Use
ApplicationFlagsSendEnvironment
to affect that. Even with this flag
set it is possible that the environment is still not available (due
to invocation messages from other applications).
The return value should not be modified or freed and is valid for as
long as cmdline
exists.
See applicationCommandLineGetenv
if you are only interested
in the value of a single environment variable.
Since: 2.28
getExitStatus
applicationCommandLineGetExitStatus Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m Int32 | Returns: the exit status |
Gets the exit status of cmdline
. See
applicationCommandLineSetExitStatus
for more information.
Since: 2.28
getIsRemote
applicationCommandLineGetIsRemote Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m Bool | Returns: |
Determines if cmdline
represents a remote invocation.
Since: 2.28
getOptionsDict
applicationCommandLineGetOptionsDict Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m VariantDict | Returns: a |
Gets the options that were passed to g_application_command_line()
.
If you did not override local_command_line()
then these are the same
options that were parsed according to the GOptionEntrys
added to the
application with applicationAddMainOptionEntries
and possibly
modified from your GApplicationhandleLocalOptions handler.
If no options were sent then an empty dictionary is returned so that
you don't need to check for Nothing
.
The data has been passed via an untrusted external process, so the types of all values must be checked before being used.
Since: 2.40
getPlatformData
applicationCommandLineGetPlatformData Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m (Maybe GVariant) | Returns: the platform data, or |
Gets the platform data associated with the invocation of cmdline
.
This is a GVariant
dictionary containing information about the
context in which the invocation occurred. It typically contains
information like the current working directory and the startup
notification ID.
It comes from an untrusted external process and hence the types of all values must be validated before being used.
For local invocation, it will be Nothing
.
Since: 2.28
getStdin
applicationCommandLineGetStdin Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> m (Maybe InputStream) | Returns: a |
Gets the stdin of the invoking process.
The InputStream
can be used to read data passed to the standard
input of the invoking process.
This doesn't work on all platforms. Presently, it is only available
on UNIX when using a D-Bus daemon capable of passing file descriptors.
If stdin is not available then Nothing
will be returned. In the
future, support may be expanded to other platforms.
You must only call this function once per commandline invocation.
Since: 2.34
getenv
applicationCommandLineGetenv Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> [Char] |
|
-> m (Maybe Text) | Returns: the value of the variable, or |
Gets the value of a particular environment variable of the command
line invocation, as would be returned by getenv
. The strings may
contain non-utf8 data.
The remote application usually does not send an environment. Use
ApplicationFlagsSendEnvironment
to affect that. Even with this flag
set it is possible that the environment is still not available (due
to invocation messages from other applications).
The return value should not be modified or freed and is valid for as
long as cmdline
exists.
Since: 2.28
printLiteral
applicationCommandLinePrintLiteral Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> Text |
|
-> m () |
Prints a message using the stdout print handler in the invoking process.
Unlike g_application_command_line_print()
, message
is not a printf()
-style
format string. Use this function if message
contains text you don't have
control over, that could include printf()
escape sequences.
Since: 2.80
printerrLiteral
applicationCommandLinePrinterrLiteral Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> Text |
|
-> m () |
Prints a message using the stderr print handler in the invoking process.
Unlike g_application_command_line_printerr()
, message
is not
a printf()
-style format string. Use this function if message
contains text
you don't have control over, that could include printf()
escape sequences.
Since: 2.80
setExitStatus
applicationCommandLineSetExitStatus Source #
:: (HasCallStack, MonadIO m, IsApplicationCommandLine a) | |
=> a |
|
-> Int32 |
|
-> m () |
Sets the exit status that will be used when the invoking process exits.
The return value of the Application::commandLine signal is passed to this function when the handler returns. This is the usual way of setting the exit status.
In the event that you want the remote invocation to continue running
and want to decide on the exit status in the future, you can use this
call. For the case of a remote invocation, the remote process will
typically exit when the last reference is dropped on cmdline
. The
exit status of the remote process will be equal to the last value
that was set with this function.
In the case that the commandline invocation is local, the situation
is slightly more complicated. If the commandline invocation results
in the mainloop running (ie: because the use-count of the application
increased to a non-zero value) then the application is considered to
have been 'successful' in a certain sense, and the exit status is
always zero. If the application use count is zero, though, the exit
status of the local ApplicationCommandLine
is used.
This method is a no-op if applicationCommandLineDone
has
been called.
Since: 2.28
Properties
arguments
The commandline that caused this Application::commandLine signal emission.
Since: 2.28
constructApplicationCommandLineArguments :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o) Source #
Construct a GValueConstruct
with valid value for the “arguments
” property. This is rarely needed directly, but it is used by new
.
isRemote
Whether this is a remote commandline.
Since: 2.28
getApplicationCommandLineIsRemote :: (MonadIO m, IsApplicationCommandLine o) => o -> m Bool Source #
Get the value of the “is-remote
” property.
When overloading is enabled, this is equivalent to
get
applicationCommandLine #isRemote
options
The options sent along with the commandline.
Since: 2.28
constructApplicationCommandLineOptions :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o) Source #
Construct a GValueConstruct
with valid value for the “options
” property. This is rarely needed directly, but it is used by new
.
platformData
Platform-specific data for the commandline.
Since: 2.28
constructApplicationCommandLinePlatformData :: (IsApplicationCommandLine o, MonadIO m) => GVariant -> m (GValueConstruct o) Source #
Construct a GValueConstruct
with valid value for the “platform-data
” property. This is rarely needed directly, but it is used by new
.