## GAppInfo GAppInfo — Application information and launch contexts |

## Synopsis

    #include <gio/gio.h>

    enum                GAppInfoCreateFlags;
                        GAppInfo;
    struct              GAppInfoIface;
                        GAppLaunchContext;
    GAppInfo *          g_app_info_create_from_commandline  (const char *commandline,
                                                             const char *application_name,
                                                             GAppInfoCreateFlags flags,
                                                             GError **error);
    GAppInfo *          g_app_info_dup                      (GAppInfo *appinfo);
    gboolean            g_app_info_equal                    (GAppInfo *appinfo1,
                                                             GAppInfo *appinfo2);
    const char *        g_app_info_get_id                   (GAppInfo *appinfo);
    const char *        g_app_info_get_name                 (GAppInfo *appinfo);
    const char *        g_app_info_get_display_name         (GAppInfo *appinfo);
    const char *        g_app_info_get_description          (GAppInfo *appinfo);
    const char *        g_app_info_get_executable           (GAppInfo *appinfo);
    const char *        g_app_info_get_commandline          (GAppInfo *appinfo);
    GIcon *             g_app_info_get_icon                 (GAppInfo *appinfo);
    gboolean            g_app_info_launch                   (GAppInfo *appinfo,
                                                             GList *files,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);
    gboolean            g_app_info_supports_files           (GAppInfo *appinfo);
    gboolean            g_app_info_supports_uris            (GAppInfo *appinfo);
    gboolean            g_app_info_launch_uris              (GAppInfo *appinfo,
                                                             GList *uris,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);
    gboolean            g_app_info_should_show              (GAppInfo *appinfo);
    gboolean            g_app_info_can_delete               (GAppInfo *appinfo);
    gboolean            g_app_info_delete                   (GAppInfo *appinfo);
    void                g_app_info_reset_type_associations  (const char *content_type);
    gboolean            g_app_info_set_as_default_for_type  (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);
    gboolean            g_app_info_set_as_default_for_extension
                                                            (GAppInfo *appinfo,
                                                             const char *extension,
                                                             GError **error);
    gboolean            g_app_info_set_as_last_used_for_type
                                                            (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);
    gboolean            g_app_info_add_supports_type        (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);
    gboolean            g_app_info_can_remove_supports_type (GAppInfo *appinfo);
    gboolean            g_app_info_remove_supports_type     (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);
    const char **       g_app_info_get_supported_types      (GAppInfo *appinfo);
    GList *             g_app_info_get_all                  (void);
    GList *             g_app_info_get_all_for_type         (const char *content_type);
    GAppInfo *          g_app_info_get_default_for_type     (const char *content_type,
                                                             gboolean must_support_uris);
    GAppInfo *          g_app_info_get_default_for_uri_scheme
                                                            (const char *uri_scheme);
    GList *             g_app_info_get_fallback_for_type    (const gchar *content_type);
    GList *             g_app_info_get_recommended_for_type (const gchar *content_type);
    gboolean            g_app_info_launch_default_for_uri   (const char *uri,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);
    void                g_app_launch_context_setenv         (GAppLaunchContext *context,
                                                             const char *variable,
                                                             const char *value);
    void                g_app_launch_context_unsetenv       (GAppLaunchContext *context,
                                                             const char *variable);
    char **             g_app_launch_context_get_environment
                                                            (GAppLaunchContext *context);
    char *              g_app_launch_context_get_display    (GAppLaunchContext *context,
                                                             GAppInfo *info,
                                                             GList *files);
    char *              g_app_launch_context_get_startup_notify_id
                                                            (GAppLaunchContext *context,
                                                             GAppInfo *info,
                                                             GList *files);
    void                g_app_launch_context_launch_failed  (GAppLaunchContext *context,
                                                             const char *startup_notify_id);
    GAppLaunchContext * g_app_launch_context_new            (void);

## Object Hierarchy

      GInterface
       +----GAppInfo

      GObject
       +----GAppLaunchContext

## Prerequisites

GAppInfo requires GObject.

## Known Implementations

GAppInfo is implemented by GDesktopAppInfo.

## Description

GAppInfo and GAppLaunchContext are used for describing and launching applications installed on the system.

As of GLib 2.20, URIs will always be converted to POSIX paths (using `g_file_get_path()`) when using `g_app_info_launch()` even if the application requested an URI and not a POSIX path. For example for an desktop-file based application with Exec key `totem %U` and a single URI, `sftp://foo/file.avi`, then `/home/user/.gvfs/sftp on foo/file.avi` will be passed. This will only work if a set of suitable GIO extensions (such as gvfs 2.26 compiled with FUSE support), is available and operational; if this is not the case, the URI will be passed unmodified to the application. Some URIs, such as `mailto:`, of course cannot be mapped to a POSIX path (in gvfs there's no FUSE mount for it); such URIs will be passed unmodified to the application.

Specifically for gvfs 2.26 and later, the POSIX URI will be mapped back to the GIO URI in the GFile constructors (since gvfs implements the GVfs extension point). As such, if the application needs to examine the URI, it needs to use `g_file_get_uri()` or similar on GFile. In other words, an application cannot assume that the URI passed to e.g. `g_file_new_for_commandline_arg()` is equal to the result of `g_file_get_uri()`. The following snippet illustrates this:

    GFile *f;
    char *uri;

    file = g_file_new_for_commandline_arg (uri_from_commandline);

    uri = g_file_get_uri (file);
    strcmp (uri, uri_from_commandline) == 0; // FALSE
    g_free (uri);

    if (g_file_has_uri_scheme (file, "cdda"))
      {
        // do something special with uri
      }
    g_object_unref (file);

This code will work when both `cdda://sr0/Track 1.wav` and `/home/user/.gvfs/cdda on sr0/Track 1.wav` is passed to the application. It should be noted that it's generally not safe for applications to rely on the format of a particular URIs. Different launcher applications (e.g. file managers) may have different ideas of what a given URI means.

## Details

### enum GAppInfoCreateFlags

    typedef enum {
      G_APP_INFO_CREATE_NONE                           = 0,         /*< nick=none >*/
      G_APP_INFO_CREATE_NEEDS_TERMINAL                 = (1 << 0),  /*< nick=needs-terminal >*/
      G_APP_INFO_CREATE_SUPPORTS_URIS                  = (1 << 1),  /*< nick=supports-uris >*/
      G_APP_INFO_CREATE_SUPPORTS_STARTUP_NOTIFICATION  = (1 << 2)   /*< nick=supports-startup-notification >*/
    } GAppInfoCreateFlags;

Flags used when creating a GAppInfo.

`G_APP_INFO_CREATE_NONE` | No flags.
`G_APP_INFO_CREATE_NEEDS_TERMINAL` | Application opens in a terminal window.
`G_APP_INFO_CREATE_SUPPORTS_URIS` | Application supports URI arguments.
`G_APP_INFO_CREATE_SUPPORTS_STARTUP_NOTIFICATION` | Application supports startup notification. Since 2.26

### GAppInfo

    typedef struct _GAppInfo GAppInfo;

Information about an installed application and methods to launch it (with file arguments).

### struct GAppInfoIface

    struct GAppInfoIface {
      GTypeInterface g_iface;

      /* Virtual Table */

      GAppInfo *   (* dup)                          (GAppInfo           *appinfo);
      gboolean     (* equal)                        (GAppInfo           *appinfo1,
                                                     GAppInfo           *appinfo2);
      const char * (* get_id)                       (GAppInfo           *appinfo);
      const char * (* get_name)                     (GAppInfo           *appinfo);
      const char * (* get_description)              (GAppInfo           *appinfo);
      const char * (* get_executable)               (GAppInfo           *appinfo);
      GIcon *      (* get_icon)                     (GAppInfo           *appinfo);
      gboolean     (* launch)                       (GAppInfo           *appinfo,
                                                     GList              *files,
                                                     GAppLaunchContext  *launch_context,
                                                     GError            **error);
      gboolean     (* supports_uris)                (GAppInfo           *appinfo);
      gboolean     (* supports_files)               (GAppInfo           *appinfo);
      gboolean     (* launch_uris)                  (GAppInfo           *appinfo,
                                                     GList              *uris,
                                                     GAppLaunchContext  *launch_context,
                                                     GError            **error);
      gboolean     (* should_show)                  (GAppInfo           *appinfo);

      /* For changing associations */
      gboolean     (* set_as_default_for_type)      (GAppInfo           *appinfo,
                                                     const char         *content_type,
                                                     GError            **error);
      gboolean     (* set_as_default_for_extension) (GAppInfo           *appinfo,
                                                     const char         *extension,
                                                     GError            **error);
      gboolean     (* add_supports_type)            (GAppInfo           *appinfo,
                                                     const char         *content_type,
                                                     GError            **error);
      gboolean     (* can_remove_supports_type)     (GAppInfo           *appinfo);
      gboolean     (* remove_supports_type)         (GAppInfo           *appinfo,
                                                     const char         *content_type,
                                                     GError            **error);
      gboolean     (* can_delete)                   (GAppInfo           *appinfo);
      gboolean     (* do_delete)                    (GAppInfo           *appinfo);
      const char * (* get_commandline)              (GAppInfo           *appinfo);
      const char * (* get_display_name)             (GAppInfo           *appinfo);
      gboolean     (* set_as_last_used_for_type)    (GAppInfo           *appinfo,
                                                     const char         *content_type,
                                                     GError            **error);
      const char ** (* get_supported_types)         (GAppInfo           *appinfo);
    };

Application Information interface, for operating system portability.

GTypeInterface `g_iface`; | The parent interface.
`dup` () | Copies a GAppInfo.
`equal` () | Checks two GAppInfos for equality.
`get_id` () | Gets a string identifier for a GAppInfo.
`get_name` () | Gets the name of the application for a GAppInfo.
`get_description` () | Gets a short description for the application described by the GAppInfo.
`get_executable` () | Gets the executable name for the GAppInfo.
`get_icon` () | Gets the GIcon for the GAppInfo.
`launch` () | Launches an application specified by the GAppInfo.
`supports_uris` () | Indicates whether the application specified supports launching URIs.
`supports_files` () | Indicates whether the application specified accepts filename arguments.
`launch_uris` () | Launches an application with a list of URIs.
`should_show` () | Returns whether an application should be shown (e.g. when getting a list of installed applications). FreeDesktop.Org Startup Notification Specification.
`set_as_default_for_type` () | Sets an application as default for a given content type.
`set_as_default_for_extension` () | Sets an application as default for a given file extension.
`add_supports_type` () | Adds to the GAppInfo information about supported file types.
`can_remove_supports_type` () | Checks for support for removing supported file types from a GAppInfo.
`remove_supports_type` () | Removes a supported application type from a GAppInfo.
`can_delete` () | Checks if a GAppInfo can be deleted. Since 2.20
`do_delete` () | Deletes a GAppInfo. Since 2.20
`get_commandline` () | Gets the commandline for the GAppInfo. Since 2.20
`get_display_name` () | Gets the display name for the GAppInfo. Since 2.24
`set_as_last_used_for_type` () | Sets the application as the last used. See `g_app_info_set_as_last_used_for_type()`.
`get_supported_types` () |

### GAppLaunchContext

    typedef struct _GAppLaunchContext GAppLaunchContext;

Integrating the launch with the launching application. This is used to handle for instance startup notification and launching the new application on the same screen as the launching window.

### g_app_info_create_from_commandline ()

    GAppInfo *          g_app_info_create_from_commandline  (const char *commandline,
                                                             const char *application_name,
                                                             GAppInfoCreateFlags flags,
                                                             GError **error);

Creates a new GAppInfo from the given information.

Note that for `commandline`, the quoting rules of the Exec key of the freedesktop.org Desktop Entry Specification are applied. For example, if the `commandline` contains percent-encoded URIs, the percent-character must be doubled in order to prevent it from being swallowed by Exec key unquoting. See the specification for exact quoting rules.

`commandline` : | the commandline to use
`application_name` : | the application name, or `NULL` to use `commandline`. [allow-none]
`flags` : | flags that can specify details of the created GAppInfo
`error` : | a GError location to store the error occurring, `NULL` to ignore.
Returns : | new GAppInfo for given command. [transfer full]

### g_app_info_dup ()

    GAppInfo *          g_app_info_dup                      (GAppInfo *appinfo);

Creates a duplicate of a GAppInfo.

`appinfo` : | a GAppInfo.
Returns : | a duplicate of `appinfo`. [transfer full]

### g_app_info_equal ()

    gboolean            g_app_info_equal                    (GAppInfo *appinfo1,
                                                             GAppInfo *appinfo2);

Checks if two GAppInfos are equal.

`appinfo1` : | the first GAppInfo.
`appinfo2` : | the second GAppInfo.
Returns : | `TRUE` if `appinfo1` is equal to `appinfo2`. `FALSE` otherwise.

### g_app_info_get_id ()

    const char *        g_app_info_get_id                   (GAppInfo *appinfo);

Gets the ID of an application. An id is a string that identifies the application. The exact format of the id is platform dependent. For instance, on Unix this is the desktop file id from the xdg menu specification.

Note that the returned ID may be `NULL`, depending on how the `appinfo` has been constructed.

`appinfo` : | a GAppInfo.
Returns : | a string containing the application's ID.

### g_app_info_get_name ()

    const char *        g_app_info_get_name                 (GAppInfo *appinfo);

Gets the installed name of the application.

`appinfo` : | a GAppInfo.
Returns : | the name of the application for `appinfo`.

### g_app_info_get_display_name ()

    const char *        g_app_info_get_display_name         (GAppInfo *appinfo);

Gets the display name of the application. The display name is often more descriptive to the user than the name itself.

`appinfo` : | a GAppInfo.
Returns : | the display name of the application for `appinfo`, or the name if no display name is available.

Since 2.24

### g_app_info_get_description ()

    const char *        g_app_info_get_description          (GAppInfo *appinfo);

Gets a human-readable description of an installed application.

`appinfo` : | a GAppInfo.
Returns : | a string containing a description of the application `appinfo`, or `NULL` if none.

### g_app_info_get_executable ()

    const char *        g_app_info_get_executable           (GAppInfo *appinfo);

Gets the executable's name for the installed application.

`appinfo` : | a GAppInfo
Returns : | a string containing the `appinfo`'s application binaries name

### g_app_info_get_commandline ()

    const char *        g_app_info_get_commandline          (GAppInfo *appinfo);

Gets the commandline with which the application will be started.

`appinfo` : | a GAppInfo
Returns : | a string containing the `appinfo`'s commandline, or `NULL` if this information is not available

Since 2.20

### g_app_info_get_icon ()

    GIcon *             g_app_info_get_icon                 (GAppInfo *appinfo);

Gets the icon for the application.

`appinfo` : | a GAppInfo.
Returns : | the default GIcon for `appinfo` or `NULL` if there is no default icon. [transfer none]

### g_app_info_launch ()

    gboolean            g_app_info_launch                   (GAppInfo *appinfo,
                                                             GList *files,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);

Launches the application. Passes `files` to the launched application as arguments, using the optional `launch_context` to get information about the details of the launcher (like what screen it is on). On error, `error` will be set accordingly.

To launch the application without arguments pass a `NULL` `files` list.

Note that even if the launch is successful the application launched can fail to start if it runs into problems during startup. There is no way to detect this.

Some URIs can be changed when passed through a GFile (for instance unsupported URIs with strange formats like mailto:), so if you have a textual URI you want to pass in as argument, consider using `g_app_info_launch_uris()` instead.

The launched application inherits the environment of the launching process, but it can be modified with `g_app_launch_context_setenv()` and `g_app_launch_context_unsetenv()`.

On UNIX, this function sets the `GIO_LAUNCHED_DESKTOP_FILE` environment variable with the path of the launched desktop file and `GIO_LAUNCHED_DESKTOP_FILE_PID` to the process id of the launched process. This can be used to ignore `GIO_LAUNCHED_DESKTOP_FILE`, should it be inherited by further processes. The `DISPLAY` and `DESKTOP_STARTUP_ID` environment variables are also set, based on information provided in `launch_context`.

`appinfo` : | a GAppInfo
`files` : | a GList of GFile objects. [allow-none][element-type GFile]
`launch_context` : | a GAppLaunchContext or `NULL`. [allow-none]
`error` : | a GError
Returns : | `TRUE` on successful launch, `FALSE` otherwise.

### g_app_info_supports_files ()

    gboolean            g_app_info_supports_files           (GAppInfo *appinfo);

Checks if the application accepts files as arguments.

`appinfo` : | a GAppInfo.
Returns : | `TRUE` if the `appinfo` supports files.

### g_app_info_supports_uris ()

    gboolean            g_app_info_supports_uris            (GAppInfo *appinfo);

Checks if the application supports reading files and directories from URIs.

`appinfo` : | a GAppInfo.
Returns : | `TRUE` if the `appinfo` supports URIs.

### g_app_info_launch_uris ()

    gboolean            g_app_info_launch_uris              (GAppInfo *appinfo,
                                                             GList *uris,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);

Launches the application. This passes the `uris` to the launched application as arguments, using the optional `launch_context` to get information about the details of the launcher (like what screen it is on). On error, `error` will be set accordingly.

To launch the application without arguments pass a `NULL` `uris` list.

Note that even if the launch is successful the application launched can fail to start if it runs into problems during startup. There is no way to detect this.

`appinfo` : | a GAppInfo
`uris` : | a GList containing URIs to launch. [allow-none][element-type utf8]
`launch_context` : | a GAppLaunchContext or `NULL`. [allow-none]
`error` : | a GError
Returns : | `TRUE` on successful launch, `FALSE` otherwise.

### g_app_info_should_show ()

    gboolean            g_app_info_should_show              (GAppInfo *appinfo);

Checks if the application info should be shown in menus that list available applications.

`appinfo` : | a GAppInfo.
Returns : | `TRUE` if the `appinfo` should be shown, `FALSE` otherwise.

### g_app_info_can_delete ()

    gboolean            g_app_info_can_delete               (GAppInfo *appinfo);

Obtains the information whether the GAppInfo can be deleted. See `g_app_info_delete()`.

`appinfo` : | a GAppInfo
Returns : | `TRUE` if `appinfo` can be deleted

Since 2.20

### g_app_info_delete ()

    gboolean            g_app_info_delete                   (GAppInfo *appinfo);

Tries to delete a GAppInfo.

On some platforms, there may be a difference between user-defined GAppInfos which can be deleted, and system-wide ones which cannot. See `g_app_info_can_delete()`.

Virtual: do_delete

`appinfo` : | a GAppInfo
Returns : | `TRUE` if `appinfo` has been deleted

Since 2.20

### g_app_info_reset_type_associations ()

    void                g_app_info_reset_type_associations  (const char *content_type);

Removes all changes to the type associations done by `g_app_info_set_as_default_for_type()`, `g_app_info_set_as_default_for_extension()`, `g_app_info_add_supports_type()` or `g_app_info_remove_supports_type()`.

`content_type` : | a content type

Since 2.20

### g_app_info_set_as_default_for_type ()

    gboolean            g_app_info_set_as_default_for_type  (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);

Sets the application as the default handler for a given type.

`appinfo` : | a GAppInfo.
`content_type` : | the content type.
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_info_set_as_default_for_extension ()

    gboolean            g_app_info_set_as_default_for_extension
                                                            (GAppInfo *appinfo,
                                                             const char *extension,
                                                             GError **error);

Sets the application as the default handler for the given file extension.

`appinfo` : | a GAppInfo.
`extension` : | a string containing the file extension (without the dot).
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_info_set_as_last_used_for_type ()

    gboolean            g_app_info_set_as_last_used_for_type
                                                            (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);

Sets the application as the last used application for a given type. This will make the application appear as first in the list returned by `g_app_info_get_recommended_for_type()`, regardless of the default application for that content type.

`appinfo` : | a GAppInfo.
`content_type` : | the content type.
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_info_add_supports_type ()

    gboolean            g_app_info_add_supports_type        (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);

Adds a content type to the application information to indicate the application is capable of opening files with the given content type.

`appinfo` : | a GAppInfo.
`content_type` : | a string.
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_info_can_remove_supports_type ()

    gboolean            g_app_info_can_remove_supports_type (GAppInfo *appinfo);

Checks if a supported content type can be removed from an application.

`appinfo` : | a GAppInfo.
Returns : | `TRUE` if it is possible to remove supported content types from a given `appinfo`, `FALSE` if not.

### g_app_info_remove_supports_type ()

    gboolean            g_app_info_remove_supports_type     (GAppInfo *appinfo,
                                                             const char *content_type,
                                                             GError **error);

Removes a supported type from an application, if possible.

`appinfo` : | a GAppInfo.
`content_type` : | a string.
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_info_get_supported_types ()

    const char **       g_app_info_get_supported_types      (GAppInfo *appinfo);

Retrieves the list of content types that `app_info` claims to support. If this information is not provided by the environment, this function will return `NULL`. This function does not take in consideration associations added with `g_app_info_add_supports_type()`, but only those exported directly by the application.

`appinfo` : | a GAppInfo that can handle files
Returns : | a list of content types. [transfer none][array zero-terminated=1][element-type utf8]

Since 2.34

### g_app_info_get_all ()

    GList *             g_app_info_get_all                  (void);

Gets a list of all of the applications currently registered on this system.

For desktop files, this includes applications that have `NoDisplay=true` set or are excluded from display by means of `OnlyShowIn` or `NotShowIn`. See `g_app_info_should_show()`. The returned list does not include applications which have the `Hidden` key set.

Returns : | a newly allocated GList of references to GAppInfos. [element-type GAppInfo][transfer full]

### g_app_info_get_all_for_type ()

    GList *             g_app_info_get_all_for_type         (const char *content_type);

Gets a list of all GAppInfos for a given content type, including the recommended and fallback GAppInfos. See `g_app_info_get_recommended_for_type()` and `g_app_info_get_fallback_for_type()`.

`content_type` : | the content type to find a GAppInfo for
Returns : | GList of GAppInfos for given `content_type` or `NULL` on error. [element-type GAppInfo][transfer full]

### g_app_info_get_default_for_type ()

    GAppInfo *          g_app_info_get_default_for_type     (const char *content_type,
                                                             gboolean must_support_uris);

Gets the default GAppInfo for a given content type.

`content_type` : | the content type to find a GAppInfo for
`must_support_uris` : | if `TRUE`, the GAppInfo is expected to support URIs
Returns : | GAppInfo for given `content_type` or `NULL` on error. [transfer full]

### g_app_info_get_default_for_uri_scheme ()

    GAppInfo *          g_app_info_get_default_for_uri_scheme
                                                            (const char *uri_scheme);

Gets the default application for handling URIs with the given URI scheme. A URI scheme is the initial part of the URI, up to but not including the ':', e.g. "http", "ftp" or "sip".

`uri_scheme` : | a string containing a URI scheme.
Returns : | GAppInfo for given `uri_scheme` or `NULL` on error. [transfer full]

### g_app_info_get_fallback_for_type ()

    GList *             g_app_info_get_fallback_for_type    (const gchar *content_type);

Gets a list of fallback GAppInfos for a given content type, i.e. those applications which claim to support the given content type by MIME type subclassing and not directly.

`content_type` : | the content type to find a GAppInfo for
Returns : | GList of GAppInfos for given `content_type` or `NULL` on error. [element-type GAppInfo][transfer full]

Since 2.28

### g_app_info_get_recommended_for_type ()

    GList *             g_app_info_get_recommended_for_type (const gchar *content_type);

Gets a list of recommended GAppInfos for a given content type, i.e. those applications which claim to support the given content type exactly, and not by MIME type subclassing. Note that the first application of the list is the last used one, i.e. the last one for which `g_app_info_set_as_last_used_for_type()` has been called.

`content_type` : | the content type to find a GAppInfo for
Returns : | GList of GAppInfos for given `content_type` or `NULL` on error. [element-type GAppInfo][transfer full]

Since 2.28

### g_app_info_launch_default_for_uri ()

    gboolean            g_app_info_launch_default_for_uri   (const char *uri,
                                                             GAppLaunchContext *launch_context,
                                                             GError **error);

Utility function that launches the default application registered to handle the specified uri. Synchronous I/O is done on the uri to detect the type of the file if required.

`uri` : | the uri to show
`launch_context` : | an optional GAppLaunchContext. [allow-none]
`error` : | a GError.
Returns : | `TRUE` on success, `FALSE` on error.

### g_app_launch_context_setenv ()

    void                g_app_launch_context_setenv         (GAppLaunchContext *context,
                                                             const char *variable,
                                                             const char *value);

Arranges for `variable` to be set to `value` in the child's environment when `context` is used to launch an application.

`context` : | a GAppLaunchContext
`variable` : | the environment variable to set
`value` : | the value for to set the variable to.

Since 2.32

### g_app_launch_context_unsetenv ()

    void                g_app_launch_context_unsetenv       (GAppLaunchContext *context,
                                                             const char *variable);

Arranges for `variable` to be unset in the child's environment when `context` is used to launch an application.

`context` : | a GAppLaunchContext
`variable` : | the environment variable to remove

Since 2.32

### g_app_launch_context_get_environment ()

    char **             g_app_launch_context_get_environment
                                                            (GAppLaunchContext *context);

Gets the complete environment variable list to be passed to the child process when `context` is used to launch an application. This is a `NULL`-terminated array of strings, where each string has the form `KEY=VALUE`.

`context` : | a GAppLaunchContext
Returns : | the child's environment. [array zero-terminated=1][transfer full]

Since 2.32

### g_app_launch_context_get_display ()

    char *              g_app_launch_context_get_display    (GAppLaunchContext *context,
                                                             GAppInfo *info,
                                                             GList *files);

Gets the display string for the `context`. This is used to ensure new applications are started on the same display as the launching application, by setting the `DISPLAY` environment variable.

`context` : | a GAppLaunchContext
`info` : | a GAppInfo
`files` : | a GList of GFile objects. [element-type GFile]
Returns : | a display string for the display.

### g_app_launch_context_get_startup_notify_id ()

    char *              g_app_launch_context_get_startup_notify_id
                                                            (GAppLaunchContext *context,
                                                             GAppInfo *info,
                                                             GList *files);

Initiates startup notification for the application and returns the `DESKTOP_STARTUP_ID` for the launched operation, if supported.

Startup notification IDs are defined in the FreeDesktop.Org Startup Notifications standard.

`context` : | a GAppLaunchContext
`info` : | a GAppInfo
`files` : | a GList of of GFile objects. [element-type GFile]
Returns : | a startup notification ID for the application, or `NULL` if not supported.

### g_app_launch_context_launch_failed ()

    void                g_app_launch_context_launch_failed  (GAppLaunchContext *context,
                                                             const char *startup_notify_id);

Called when an application has failed to launch, so that it can cancel the application startup notification started in `g_app_launch_context_get_startup_notify_id()`.

`context` : | a GAppLaunchContext.
`startup_notify_id` : | the startup notification id that was returned by `g_app_launch_context_get_startup_notify_id()`.

### g_app_launch_context_new ()

    GAppLaunchContext * g_app_launch_context_new            (void);

Creates a new application launch context. This is not normally used, instead you instantiate a subclass of this, such as GdkAppLaunchContext.

Returns : | a GAppLaunchContext.