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GIO Reference Manual | ![]() |
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Top | Description |
#include <gio/gio.h> enum GFileAttributeType; enum GFileAttributeInfoFlags; enum GFileAttributeStatus; GFileAttributeInfo; GFileAttributeInfoList; GFileAttributeInfoList * g_file_attribute_info_list_new (void); GFileAttributeInfoList * g_file_attribute_info_list_ref (GFileAttributeInfoList *list); void g_file_attribute_info_list_unref (GFileAttributeInfoList *list); GFileAttributeInfoList * g_file_attribute_info_list_dup (GFileAttributeInfoList *list); const GFileAttributeInfo * g_file_attribute_info_list_lookup (GFileAttributeInfoList *list, const char *name); void g_file_attribute_info_list_add (GFileAttributeInfoList *list, const char *name, GFileAttributeType type, GFileAttributeInfoFlags flags);
File attributes in GIO consist of a list of key-value pairs.
Keys are strings that contain a key namespace and a key name, separated by a colon, e.g. "namespace:keyname". Namespaces are included to sort key-value pairs by namespaces for relevance. Keys can be retrived using wildcards, e.g. "standard::*" will return all of the keys in the "standard" namespace.
Values are stored within the list in GFileAttributeValue structures.
Values can store different types, listed in the enum GFileAttributeType.
Upon creation of a GFileAttributeValue, the type will be set to
G_FILE_ATTRIBUTE_TYPE_INVALID
.
The list of possible attributes for a filesystem (pointed to by a GFile) is availible as a GFileAttributeInfoList. This list is queryable by key names as indicated earlier.
Classes that implement GFileIface will create a GFileAttributeInfoList and install default keys and values for their given file system, architecture, and other possible implementation details (e.g., on a UNIX system, a file attribute key will be registered for the user id for a given file).
Table 1. GFileAttributes Default Namespaces
Namspace | Description |
---|---|
"standard" | The "Standard" namespace. General file information that any application may need should be put in this namespace. Examples include the file's name, type, and size. |
"etag" | The "Entity Tag" namespace. Currently, the only key in this namespace is "value", which contains the value of the current entity tag. |
"id" | The "Identification" namespace. This namespace is used by file managers and applications that list directories to check for loops and to uniquely identify files. |
"access" | The "Access" namespace. Used to check
if a user has the proper privilidges to access files and perform
file operations. Keys in this namespace are made to be generic
and easily understood, e.g. the "can_read" key is TRUE if
the current user has permission to read the file. UNIX permissions and
NTFS ACLs in Windows should be mapped to these values. |
"mountable" | The "Mountable" namespace. Includes
simple boolean keys for checking if a file or path supports mount operations, e.g.
mount, unmount, eject. These are used for files of type G_FILE_TYPE_MOUNTABLE . |
"time" | The "Time" namespace. Includes file access, changed, created times. |
"unix" | The "Unix" namespace. Includes UNIX-specific information and may not be available for all files. Examples include the UNIX "UID", "GID", etc. |
"dos" | The "DOS" namespace. Includes DOS-specific information and may not be available for all files. Examples include "is_system" for checking if a file is marked as a system file, and "is_archive" for checking if a file is marked as an archive file. |
"owner" | The "Owner" namespace. Includes information about who owns a file. May not be available for all file systems. Examples include "user" for getting the user name of the file owner. This information is often mapped from some backend specific data such as a unix UID. |
"thumbnail" | The "Thumbnail" namespace. Includes information about file thumbnails and their location within the file system. Exaples of keys in this namespace include "path" to get the location of a thumbnail, and "failed" to check if thumbnailing of the file failed. |
"filesystem" | The "Filesystem" namespace. Gets information about the file system where a file is located, such as its type, how much space is left available, and the overall size of the file system. |
"gvfs" | The "GVFS" namespace. Keys in this namespace contain information about the current GVFS backend in use. |
"xattr" | The "xattr" namespace. Gets information about extended user attributes. See attr(5). The "user." prefix of the extended user attribute name is stripped away when constructing keys in this namespace, e.g. "xattr::mime_type" for the extended attribute with the name "user.mime_type". Note that this information is only available if GLib has been built with extended attribute support. |
"xattr-sys" | The "xattr-sys" namespace. Gets information about extended attributes which are not user-specific. See attr(5). Note that this information is only available if GLib has been built with extended attribute support. |
"selinux" | The "SELinux" namespace. Includes information about the SELinux context of files. Note that this information is only available if GLib has been built with SELinux support. |
Please note that these are not all of the possible namespaces. More namespaces can be added from GIO modules or by individual applications. For more information about writing GIO modules, see GIOModule.
Table 2. GFileAttributes Built-in Keys and Value Types
Note that there are no predefined keys in the "xattr" and "xattr-sys"
namespaces. Keys for the "xattr" namespace are constructed by stripping
away the "user." prefix from the extended user attribute, and prepending
"xattr::". Keys for the "xattr-sys" namespace are constructed by
concatenating "xattr-sys::" with the extended attribute name. All extended
attribute values are returned as hex-encoded strings in which bytes outside
the ASCII range are encoded as hexadecimal escape sequences of the form
\xnn
.
typedef enum { G_FILE_ATTRIBUTE_TYPE_INVALID = 0, G_FILE_ATTRIBUTE_TYPE_STRING, G_FILE_ATTRIBUTE_TYPE_BYTE_STRING, /* zero terminated string of non-zero bytes */ G_FILE_ATTRIBUTE_TYPE_BOOLEAN, G_FILE_ATTRIBUTE_TYPE_UINT32, G_FILE_ATTRIBUTE_TYPE_INT32, G_FILE_ATTRIBUTE_TYPE_UINT64, G_FILE_ATTRIBUTE_TYPE_INT64, G_FILE_ATTRIBUTE_TYPE_OBJECT } GFileAttributeType;
The data types for file attributes.
indicates an invalid or uninitalized type. | |
a null terminated UTF8 string. | |
a zero terminated string of non-zero bytes. | |
a boolean value. | |
an unsigned 4-byte/32-bit integer. | |
a signed 4-byte/32-bit integer. | |
an unsigned 8-byte/64-bit integer. | |
a signed 8-byte/64-bit integer. | |
a GObject. |
typedef enum { G_FILE_ATTRIBUTE_INFO_NONE = 0, G_FILE_ATTRIBUTE_INFO_COPY_WITH_FILE = (1 << 0), G_FILE_ATTRIBUTE_INFO_COPY_WHEN_MOVED = (1 << 1) } GFileAttributeInfoFlags;
Flags specifying the behaviour of an attribute.
typedef enum { G_FILE_ATTRIBUTE_STATUS_UNSET = 0, G_FILE_ATTRIBUTE_STATUS_SET, G_FILE_ATTRIBUTE_STATUS_ERROR_SETTING } GFileAttributeStatus;
Used by g_file_set_attributes_from_info()
when setting file attributes.
typedef struct { char *name; GFileAttributeType type; GFileAttributeInfoFlags flags; } GFileAttributeInfo;
Information about a specific attribute.
char * |
the name of the attribute. |
GFileAttributeType |
the GFileAttributeType type of the attribute. |
GFileAttributeInfoFlags |
a set of GFileAttributeInfoFlags. |
typedef struct { GFileAttributeInfo *infos; int n_infos; } GFileAttributeInfoList;
Acts as a lightweight registry for possible valid file attributes. The registry stores Key-Value pair formats as GFileAttributeInfos.
GFileAttributeInfo * |
an array of GFileAttributeInfos. |
int |
the number of values in the array. |
GFileAttributeInfoList * g_file_attribute_info_list_new (void);
Creates a new file attribute info list.
Returns : |
a GFileAttributeInfoList. |
GFileAttributeInfoList * g_file_attribute_info_list_ref (GFileAttributeInfoList *list);
References a file attribute info list.
|
a GFileAttributeInfoList to reference. |
Returns : |
GFileAttributeInfoList or NULL on error.
|
void g_file_attribute_info_list_unref (GFileAttributeInfoList *list);
Removes a reference from the given list
. If the reference count
falls to zero, the list
is deleted.
|
The GFileAttributeInfoList to unreference. |
GFileAttributeInfoList * g_file_attribute_info_list_dup (GFileAttributeInfoList *list);
Makes a duplicate of a file attribute info list.
|
a GFileAttributeInfoList to duplicate. |
Returns : |
a copy of the given list .
|
const GFileAttributeInfo * g_file_attribute_info_list_lookup (GFileAttributeInfoList *list, const char *name);
Gets the file attribute with the name name
from list
.
|
a GFileAttributeInfoList. |
|
the name of the attribute to lookup. |
Returns : |
a GFileAttributeInfo for the name , or NULL if an
attribute isn't found.
|
void g_file_attribute_info_list_add (GFileAttributeInfoList *list, const char *name, GFileAttributeType type, GFileAttributeInfoFlags flags);
Adds a new attribute with name
to the list
, setting
its type
and flags
.
|
a GFileAttributeInfoList. |
|
the name of the attribute to add. |
|
the GFileAttributeType for the attribute. |
|
GFileAttributeInfoFlags for the attribute. |