GUnixFDList

GUnixFDList — An object containing a set of UNIX file descriptors

Types and Values

Object Hierarchy

    GObject
    ╰── GUnixFDList

Includes

#include <gio/gunixfdlist.h>

Description

A GUnixFDList contains a list of file descriptors. It owns the file descriptors that it contains, closing them when finalized.

It may be wrapped in a GUnixFDMessage and sent over a GSocket in the G_SOCKET_ADDRESS_UNIX family by using g_socket_send_message() and received using g_socket_receive_message().

Note that <gio/gunixfdlist.h> belongs to the UNIX-specific GIO interfaces, thus you have to use the gio-unix-2.0.pc pkg-config file when using it.

Functions

g_unix_fd_list_new_from_array ()

GUnixFDList *
g_unix_fd_list_new_from_array (const gint *fds,
                               gint n_fds);

Creates a new GUnixFDList containing the file descriptors given in fds . The file descriptors become the property of the new list and may no longer be used by the caller. The array itself is owned by the caller.

Each file descriptor in the array should be set to close-on-exec.

If n_fds is -1 then fds must be terminated with -1.

Parameters

fds

the initial list of file descriptors.

[array length=n_fds]

n_fds

the length of fds, or -1

 

Returns

a new GUnixFDList

Since: 2.24


g_unix_fd_list_new ()

GUnixFDList *
g_unix_fd_list_new (void);

Creates a new GUnixFDList containing no file descriptors.

Returns

a new GUnixFDList

Since: 2.24


g_unix_fd_list_get_length ()

gint
g_unix_fd_list_get_length (GUnixFDList *list);

Gets the length of list (ie: the number of file descriptors contained within).

Parameters

list

a GUnixFDList

 

Returns

the length of list

Since: 2.24


g_unix_fd_list_get ()

gint
g_unix_fd_list_get (GUnixFDList *list,
                    gint index_,
                    GError **error);

Gets a file descriptor out of list .

index_ specifies the index of the file descriptor to get. It is a programmer error for index_ to be out of range; see g_unix_fd_list_get_length().

The file descriptor is duplicated using dup() and set as close-on-exec before being returned. You must call close() on it when you are done.

A possible cause of failure is exceeding the per-process or system-wide file descriptor limit.

Parameters

list

a GUnixFDList

 

index_

the index into the list

 

error

a GError pointer

 

Returns

the file descriptor, or -1 in case of error

Since: 2.24


g_unix_fd_list_peek_fds ()

const gint *
g_unix_fd_list_peek_fds (GUnixFDList *list,
                         gint *length);

Returns the array of file descriptors that is contained in this object.

After this call, the descriptors remain the property of list . The caller must not close them and must not free the array. The array is valid only until list is changed in any way.

If length is non-NULL then it is set to the number of file descriptors in the returned array. The returned array is also terminated with -1.

This function never returns NULL. In case there are no file descriptors contained in list , an empty array is returned.

Parameters

list

a GUnixFDList

 

length

pointer to the length of the returned array, or NULL.

[out][optional]

Returns

an array of file descriptors.

[array length=length][transfer none]

Since: 2.24


g_unix_fd_list_steal_fds ()

gint *
g_unix_fd_list_steal_fds (GUnixFDList *list,
                          gint *length);

Returns the array of file descriptors that is contained in this object.

After this call, the descriptors are no longer contained in list . Further calls will return an empty list (unless more descriptors have been added).

The return result of this function must be freed with g_free(). The caller is also responsible for closing all of the file descriptors. The file descriptors in the array are set to close-on-exec.

If length is non-NULL then it is set to the number of file descriptors in the returned array. The returned array is also terminated with -1.

This function never returns NULL. In case there are no file descriptors contained in list , an empty array is returned.

Parameters

list

a GUnixFDList

 

length

pointer to the length of the returned array, or NULL.

[out][optional]

Returns

an array of file descriptors.

[array length=length][transfer full]

Since: 2.24


g_unix_fd_list_append ()

gint
g_unix_fd_list_append (GUnixFDList *list,
                       gint fd,
                       GError **error);

Adds a file descriptor to list .

The file descriptor is duplicated using dup(). You keep your copy of the descriptor and the copy contained in list will be closed when list is finalized.

A possible cause of failure is exceeding the per-process or system-wide file descriptor limit.

The index of the file descriptor in the list is returned. If you use this index with g_unix_fd_list_get() then you will receive back a duplicated copy of the same file descriptor.

Parameters

list

a GUnixFDList

 

fd

a valid open file descriptor

 

error

a GError pointer

 

Returns

the index of the appended fd in case of success, else -1 (and error is set)

Since: 2.24

Types and Values

GUnixFDList

typedef struct _GUnixFDList GUnixFDList;

GUnixFDList is an opaque data structure and can only be accessed using the following functions.

See Also

GUnixFDMessage