### Struct

# GLib KeyFile

since: 2.0

#### Description

    struct GKeyFile {
      /* No available fields */
    }

`GKeyFile` parses .ini-like config files.

`GKeyFile` lets you parse, edit or create files containing groups of key-value pairs, which we call “key files” for lack of a better name. Several freedesktop.org specifications use key files now, e.g the Desktop Entry Specification and the Icon Theme Specification.

The syntax of key files is described in detail in the Desktop Entry Specification, here is a quick summary: Key files consists of groups of key-value pairs, interspersed with comments.

    # this is just an example
    # there can be comments before the first group

    [First Group]

    Name=Key File Example\tthis value shows\nescaping

    # localized strings are stored in multiple key-value pairs
    Welcome=Hello
    Welcome[de]=Hallo
    Welcome[fr_FR]=Bonjour
    Welcome[it]=Ciao

    [Another Group]

    Numbers=2;20;-200;0

    Booleans=true;false;true;true

Lines beginning with a ‘#’ and blank lines are considered comments.

Groups are started by a header line containing the group name enclosed in ‘[‘ and ‘]’, and ended implicitly by the start of the next group or the end of the file. Each key-value pair must be contained in a group.

Key-value pairs generally have the form `key=value`, with the exception of localized strings, which have the form `key[locale]=value`, with a locale identifier of the form `lang_COUNTRY@MODIFIER` where `COUNTRY` and `MODIFIER` are optional. Space before and after the ‘=’ character are ignored. Newline, tab, carriage return and backslash characters in value are escaped as `\n`, `\t`, `\r`, and `\\\\`, respectively. To preserve leading spaces in values, these can also be escaped as `\s`.

Key files can store strings (possibly with localized variants), integers, booleans and lists of these. Lists are separated by a separator character, typically ‘;’ or ‘,’. To use the list separator character in a value in a list, it has to be escaped by prefixing it with a backslash.

This syntax is obviously inspired by the .ini files commonly met on Windows, but there are some important differences:

- .ini files use the ‘;’ character to begin comments, key files use the ‘#’ character.

- Key files do not allow for ungrouped keys meaning only comments can precede the first group.

- Key files are always encoded in UTF-8.

- Key and Group names are case-sensitive. For example, a group called [GROUP] is a different from [group].

- .ini files don’t have a strongly typed boolean entry type, they only have GetProfileInt(). In key files, only true and false (in lower case) are allowed.

Note that in contrast to the Desktop Entry Specification, groups in key files may contain the same key multiple times; the last entry wins. Key files may also contain multiple groups with the same name; they are merged together. Another difference is that keys and group names in key files are not restricted to ASCII characters.

Here is an example of loading a key file and reading a value:

    g_autoptr(GError) error = NULL;
    g_autoptr(GKeyFile) key_file = g_key_file_new ();

    if (!g_key_file_load_from_file (key_file, "key-file.ini", flags, &error))
      {
        if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
          g_warning ("Error loading key file: %s", error->message);
        return;
      }

    g_autofree gchar *val = g_key_file_get_string (key_file, "Group Name", "SomeKey", &error);
    if (val == NULL &&
        !g_error_matches (error, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_KEY_NOT_FOUND))
      {
        g_warning ("Error finding key in key file: %s", error->message);
        return;
      }
    else if (val == NULL)
      {
        // Fall back to a default value.
        val = g_strdup ("default-value");
      }

Here is an example of creating and saving a key file:

    g_autoptr(GKeyFile) key_file = g_key_file_new ();
    const gchar *val = …;
    g_autoptr(GError) error = NULL;

    g_key_file_set_string (key_file, "Group Name", "SomeKey", val);

    // Save as a file.
    if (!g_key_file_save_to_file (key_file, "key-file.ini", &error))
      {
        g_warning ("Error saving key file: %s", error->message);
        return;
      }

    // Or store to a GBytes for use elsewhere.
    gsize data_len;
    g_autofree guint8 *data = (guint8 *) g_key_file_to_data (key_file, &data_len, &error);
    if (data == NULL)
      {
        g_warning ("Error saving key file: %s", error->message);
        return;
      }
    g_autoptr(GBytes) bytes = g_bytes_new_take (g_steal_pointer (&data), data_len);

Available since: 2.0

#### Constructors

###### g_key_file_new

Creates a new empty `GKeyFile` object. Use g_key_file_load_from_file(), g_key_file_load_from_data(), `g_key_file_load_from_dirs()` or `g_key_file_load_from_data_dirs()` to read an existing key file.

since: 2.6

#### Functions

###### g_key_file_error_quark

No description available.

since: 2.0

#### Instance methods

###### g_key_file_free

Clears all keys and groups from `key_file`, and decreases the reference count by 1. If the reference count reaches zero, frees the key file and all its allocated memory.

since: 2.6

###### g_key_file_get_boolean

Returns the value associated with `key` under `group_name` as a boolean.

since: 2.6

###### g_key_file_get_boolean_list

Returns the values associated with `key` under `group_name` as booleans.

since: 2.6

###### g_key_file_get_comment

Retrieves a comment above `key` from `group_name`. If `key` is `NULL` then `comment` will be read from above `group_name`. If both `key` and `group_name` are `NULL`, then `comment` will be read from above the first group in the file.

since: 2.6

###### g_key_file_get_double

Returns the value associated with `key` under `group_name` as a double. If `group_name` is `NULL`, the start_group is used.

since: 2.12

###### g_key_file_get_double_list

Returns the values associated with `key` under `group_name` as doubles.

since: 2.12

###### g_key_file_get_groups

Returns all groups in the key file loaded with `key_file`. The array of returned groups will be `NULL`-terminated, so `length` may optionally be `NULL`.

since: 2.6

###### g_key_file_get_int64

Returns the value associated with `key` under `group_name` as a signed 64-bit integer. This is similar to `g_key_file_get_integer()` but can return 64-bit results without truncation.

since: 2.26

###### g_key_file_get_integer

Returns the value associated with `key` under `group_name` as an integer.

since: 2.6

###### g_key_file_get_integer_list

Returns the values associated with `key` under `group_name` as integers.

since: 2.6

###### g_key_file_get_keys

Returns all keys for the group name `group_name`. The array of returned keys will be `NULL`-terminated, so `length` may optionally be `NULL`. In the event that the `group_name` cannot be found, `NULL` is returned and `error` is set to `G_KEY_FILE_ERROR_GROUP_NOT_FOUND`.

since: 2.6

###### g_key_file_get_locale_for_key

Returns the actual locale which the result of `g_key_file_get_locale_string()` or `g_key_file_get_locale_string_list()` came from.

since: 2.56

###### g_key_file_get_locale_string

Returns the value associated with `key` under `group_name` translated in the given `locale` if available. If `locale` is `NULL` then the current locale is assumed.

since: 2.6

###### g_key_file_get_locale_string_list

Returns the values associated with `key` under `group_name` translated in the given `locale` if available. If `locale` is `NULL` then the current locale is assumed.

since: 2.6

###### g_key_file_get_start_group

Returns the name of the start group of the file.

since: 2.6

###### g_key_file_get_string

Returns the string value associated with `key` under `group_name`. Unlike g_key_file_get_value(), this function handles escape sequences like \s.

since: 2.6

###### g_key_file_get_string_list

Returns the values associated with `key` under `group_name`.

since: 2.6

###### g_key_file_get_uint64

Returns the value associated with `key` under `group_name` as an unsigned 64-bit integer. This is similar to `g_key_file_get_integer()` but can return large positive results without truncation.

since: 2.26

###### g_key_file_get_value

Returns the raw value associated with `key` under `group_name`. Use `g_key_file_get_string()` to retrieve an unescaped UTF-8 string.

since: 2.6

###### g_key_file_has_group

Looks whether the key file has the group `group_name`.

since: 2.6

###### g_key_file_has_key

Looks whether the key file has the key `key` in the group `group_name`.

since: 2.6

###### g_key_file_load_from_bytes

Loads a key file from the data in `bytes` into an empty `GKeyFile` structure. If the object cannot be created then %error is set to a `GKeyFileError`.

since: 2.50

###### g_key_file_load_from_data

Loads a key file from memory into an empty `GKeyFile` structure. If the object cannot be created then %error is set to a `GKeyFileError`.

since: 2.6

###### g_key_file_load_from_data_dirs

This function looks for a key file named `file` in the paths returned from `g_get_user_data_dir()` and g_get_system_data_dirs(), loads the file into `key_file` and returns the file’s full path in `full_path`. If the file could not be loaded then an %error is set to either a `GFileError` or `GKeyFileError`.

since: 2.6

###### g_key_file_load_from_dirs

This function looks for a key file named `file` in the paths specified in `search_dirs`, loads the file into `key_file` and returns the file’s full path in `full_path`.

since: 2.14

###### g_key_file_load_from_file

Loads a key file into an empty `GKeyFile` structure.

since: 2.6

###### g_key_file_ref

Increases the reference count of `key_file`.

since: 2.32

###### g_key_file_remove_comment

Removes a comment above `key` from `group_name`. If `key` is `NULL` then `comment` will be removed above `group_name`. If both `key` and `group_name` are `NULL`, then `comment` will be removed above the first group in the file.

since: 2.6

###### g_key_file_remove_group

Removes the specified group, `group_name`, from the key file.

since: 2.6

###### g_key_file_remove_key

Removes `key` in `group_name` from the key file.

since: 2.6

###### g_key_file_save_to_file

Writes the contents of `key_file` to `filename` using g_file_set_contents(). If you need stricter guarantees about durability of the written file than are provided by g_file_set_contents(), use `g_file_set_contents_full()` with the return value of g_key_file_to_data().

since: 2.40

###### g_key_file_set_boolean

Associates a new boolean value with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.6

###### g_key_file_set_boolean_list

Associates a list of boolean values with `key` under `group_name`. If `key` cannot be found then it is created. If `group_name` is `NULL`, the start_group is used.

since: 2.6

###### g_key_file_set_comment

Places a comment above `key` from `group_name`.

since: 2.6

###### g_key_file_set_double

Associates a new double value with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.12

###### g_key_file_set_double_list

Associates a list of double values with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.12

###### g_key_file_set_int64

Associates a new integer value with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.26

###### g_key_file_set_integer

Associates a new integer value with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.6

###### g_key_file_set_integer_list

Associates a list of integer values with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.6

###### g_key_file_set_list_separator

Sets the character which is used to separate values in lists. Typically ‘;’ or ‘,’ are used as separators. The default list separator is ‘;’.

since: 2.6

###### g_key_file_set_locale_string

Associates a string value for `key` and `locale` under `group_name`. If the translation for `key` cannot be found then it is created.

since: 2.6

###### g_key_file_set_locale_string_list

Associates a list of string values for `key` and `locale` under `group_name`. If the translation for `key` cannot be found then it is created.

since: 2.6

###### g_key_file_set_string

Associates a new string value with `key` under `group_name`. If `key` cannot be found then it is created. If `group_name` cannot be found then it is created. Unlike g_key_file_set_value(), this function handles characters that need escaping, such as newlines.

since: 2.6

###### g_key_file_set_string_list

Associates a list of string values for `key` under `group_name`. If `key` cannot be found then it is created. If `group_name` cannot be found then it is created.

since: 2.6

###### g_key_file_set_uint64

Associates a new integer value with `key` under `group_name`. If `key` cannot be found then it is created.

since: 2.26

###### g_key_file_set_value

Associates a new value with `key` under `group_name`.

since: 2.6

###### g_key_file_to_data

This function outputs `key_file` as a string.

since: 2.6

###### g_key_file_unref

Decreases the reference count of `key_file` by 1. If the reference count reaches zero, frees the key file and all its allocated memory.

since: 2.32