Key-value file parser

## Key-value file parser Key-value file parser — parses `.ini`-like config files |

## Synopsis

    #include <glib.h>

                        GKeyFile;
    #define             G_KEY_FILE_ERROR
    enum                GKeyFileError;
    enum                GKeyFileFlags;
    GKeyFile*           g_key_file_new                      (void);
    void                g_key_file_free                     (GKeyFile *key_file);
    void                g_key_file_set_list_separator       (GKeyFile *key_file,
                                                             gchar separator);
    gboolean            g_key_file_load_from_file           (GKeyFile *key_file,
                                                             const gchar *file,
                                                             GKeyFileFlags flags,
                                                             GError **error);
    gboolean            g_key_file_load_from_data           (GKeyFile *key_file,
                                                             const gchar *data,
                                                             gsize length,
                                                             GKeyFileFlags flags,
                                                             GError **error);
    gboolean            g_key_file_load_from_data_dirs      (GKeyFile *key_file,
                                                             const gchar *file,
                                                             gchar **full_path,
                                                             GKeyFileFlags flags,
                                                             GError **error);
    gchar*              g_key_file_to_data                  (GKeyFile *key_file,
                                                             gsize *length,
                                                             GError **error);
    gchar*              g_key_file_get_start_group          (GKeyFile *key_file);
    gchar**             g_key_file_get_groups               (GKeyFile *key_file,
                                                             gsize *length);
    gchar**             g_key_file_get_keys                 (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             gsize *length,
                                                             GError **error);
    gboolean            g_key_file_has_group                (GKeyFile *key_file,
                                                             const gchar *group_name);
    gboolean            g_key_file_has_key                  (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

    gchar*              g_key_file_get_value                (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    gchar*              g_key_file_get_string               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    gchar*              g_key_file_get_locale_string        (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             GError **error);
    gboolean            g_key_file_get_boolean              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    gint                g_key_file_get_integer              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    gdouble             g_key_file_get_double               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    gchar**             g_key_file_get_string_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);
    gchar**             g_key_file_get_locale_string_list   (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             gsize *length,
                                                             GError **error);
    gboolean*           g_key_file_get_boolean_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);
    gint*               g_key_file_get_integer_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);
    gdouble*            g_key_file_get_double_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);
    gchar*              g_key_file_get_comment              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

    void                g_key_file_set_value                (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *value);
    void                g_key_file_set_string               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *string);
    void                g_key_file_set_locale_string        (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             const gchar *string);
    void                g_key_file_set_boolean              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gboolean value);
    void                g_key_file_set_integer              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gint value);
    void                g_key_file_set_double               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gdouble value);
    void                g_key_file_set_string_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar * const list[],
                                                             gsize length);
    void                g_key_file_set_locale_string_list   (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             const gchar * const list[],
                                                             gsize length);
    void                g_key_file_set_boolean_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gboolean list[],
                                                             gsize length);
    void                g_key_file_set_integer_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gint list[],
                                                             gsize length);
    void                g_key_file_set_double_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gdouble list[],
                                                             gsize length);
    void                g_key_file_set_comment              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *comment,
                                                             GError **error);
    void                g_key_file_remove_group             (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             GError **error);
    void                g_key_file_remove_key               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);
    void                g_key_file_remove_comment           (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

## Description

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]=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`. Space before and after the '=' character are ignored. Newline, tab, carriage return and backslash characters 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 allow only comments before 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 group from `[group]`.

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.

## Details

### GKeyFile

    typedef struct _GKeyFile GKeyFile;

The GKeyFile struct contains only private fields and should not be used directly.

### G_KEY_FILE_ERROR

    #define G_KEY_FILE_ERROR g_key_file_error_quark()

Error domain for key file parsing. Errors in this domain will be from the GKeyFileError enumeration. See GError for information on error domains.

### enum GKeyFileError

    typedef enum
    {
      G_KEY_FILE_ERROR_UNKNOWN_ENCODING,
      G_KEY_FILE_ERROR_PARSE,
      G_KEY_FILE_ERROR_NOT_FOUND,
      G_KEY_FILE_ERROR_KEY_NOT_FOUND,
      G_KEY_FILE_ERROR_GROUP_NOT_FOUND,
      G_KEY_FILE_ERROR_INVALID_VALUE
    } GKeyFileError;

Error codes returned by key file parsing.

`G_KEY_FILE_ERROR_UNKNOWN_ENCODING` | the text being parsed was in an unknown encoding
`G_KEY_FILE_ERROR_PARSE` | document was ill-formed
`G_KEY_FILE_ERROR_NOT_FOUND` | the file was not found
`G_KEY_FILE_ERROR_KEY_NOT_FOUND` | a requested key was not found
`G_KEY_FILE_ERROR_GROUP_NOT_FOUND` | a requested group was not found
`G_KEY_FILE_ERROR_INVALID_VALUE` | a value could not be parsed

### enum GKeyFileFlags

    typedef enum
    {
      G_KEY_FILE_NONE              = 0,
      G_KEY_FILE_KEEP_COMMENTS     = 1 << 0,
      G_KEY_FILE_KEEP_TRANSLATIONS = 1 << 1
    } GKeyFileFlags;

Flags which influence the parsing.

`G_KEY_FILE_NONE` | No flags, default behaviour
`G_KEY_FILE_KEEP_COMMENTS` | Use this flag if you plan to write the (possibly modified) contents of the key file back to a file; otherwise all comments will be lost when the key file is written back.
`G_KEY_FILE_KEEP_TRANSLATIONS` | Use this flag if you plan to write the (possibly modified) contents of the key file back to a file; otherwise only the translations for the current language will be written back.

### g_key_file_new ()

    GKeyFile*           g_key_file_new                      (void);

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

Returns : | an empty GKeyFile.

Since 2.6

### g_key_file_free ()

    void                g_key_file_free                     (GKeyFile *key_file);

Frees a GKeyFile.

`key_file` : | a GKeyFile

Since 2.6

### g_key_file_set_list_separator ()

    void                g_key_file_set_list_separator       (GKeyFile *key_file,
                                                             gchar separator);

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

`key_file` : | a GKeyFile
`separator` : | the separator

Since 2.6

### g_key_file_load_from_file ()

    gboolean            g_key_file_load_from_file           (GKeyFile *key_file,
                                                             const gchar *file,
                                                             GKeyFileFlags flags,
                                                             GError **error);

Loads a key file into an empty GKeyFile structure. If the file could not be loaded then `error` is set to either a GFileError or GKeyFileError.

`key_file` : | an empty GKeyFile struct
`file` : | the path of a filename to load, in the GLib file name encoding
`flags` : | flags from GKeyFileFlags
`error` : | return location for a GError, or `NULL`
Returns : | `TRUE` if a key file could be loaded, `FALSE` othewise

Since 2.6

### g_key_file_load_from_data ()

    gboolean            g_key_file_load_from_data           (GKeyFile *key_file,
                                                             const gchar *data,
                                                             gsize length,
                                                             GKeyFileFlags flags,
                                                             GError **error);

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

`key_file` : | an empty GKeyFile struct
`data` : | key file loaded in memory.
`length` : | the length of `data` in bytes
`flags` : | flags from GKeyFileFlags
`error` : | return location for a GError, or `NULL`
Returns : | `TRUE` if a key file could be loaded, `FALSE` othewise

Since 2.6

### g_key_file_load_from_data_dirs ()

    gboolean            g_key_file_load_from_data_dirs      (GKeyFile *key_file,
                                                             const gchar *file,
                                                             gchar **full_path,
                                                             GKeyFileFlags flags,
                                                             GError **error);

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.

`key_file` : | an empty GKeyFile struct
`file` : | a relative path to a filename to open and parse
`full_path` : | return location for a string containing the full path of the file, or `NULL`
`flags` : | flags from GKeyFileFlags
`error` : | return location for a GError, or `NULL`
Returns : | `TRUE` if a key file could be loaded, `FALSE` othewise

Since 2.6

### g_key_file_to_data ()

    gchar*              g_key_file_to_data                  (GKeyFile *key_file,
                                                             gsize *length,
                                                             GError **error);

This function outputs `key_file` as a string.

`key_file` : | a GKeyFile
`length` : | return location for the length of the returned string, or `NULL`
`error` : | return location for a GError, or `NULL`
Returns : | a newly allocated string holding the contents of the GKeyFile

Since 2.6

### g_key_file_get_start_group ()

    gchar*              g_key_file_get_start_group          (GKeyFile *key_file);

Returns the name of the start group of the file.

`key_file` : | a GKeyFile
Returns : | The start group of the key file.

Since 2.6

### g_key_file_get_groups ()

    gchar**             g_key_file_get_groups               (GKeyFile *key_file,
                                                             gsize *length);

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`.

`key_file` : | a GKeyFile
`length` : | return location for the number of returned groups, or `NULL`
Returns : | a newly-allocated `NULL`-terminated array of strings. Use `g_strfreev()` to free it.

Since 2.6

### g_key_file_get_keys ()

    gchar**             g_key_file_get_keys                 (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             gsize *length,
                                                             GError **error);

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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`length` : | return location for the number of keys returned, or `NULL`
`error` : | return location for a GError, or `NULL`
Returns : | a newly-allocated `NULL`-terminated array of strings. Use `g_strfreev()` to free it.

Since 2.6

### g_key_file_has_group ()

    gboolean            g_key_file_has_group                (GKeyFile *key_file,
                                                             const gchar *group_name);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
Returns : | `TRUE` if `group_name` is a part of `key_file`, `FALSE` otherwise.

Since 2.6

### g_key_file_has_key ()

    gboolean            g_key_file_has_key                  (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key name
`error` : | return location for a GError
Returns : | `TRUE` if `key` is a part of `group_name`, `FALSE` otherwise.

Since 2.6

### g_key_file_get_value ()

    gchar*              g_key_file_get_value                (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

In the event the key cannot be found, `NULL` is returned and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. 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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`error` : | return location for a GError, or `NULL`
Returns : | a newly allocated string or `NULL` if the specified key cannot be found.

Since 2.6

### g_key_file_get_string ()

    gchar*              g_key_file_get_string               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

In the event the key cannot be found, `NULL` is returned and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. 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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`error` : | return location for a GError, or `NULL`
Returns : | a newly allocated string or `NULL` if the specified key cannot be found.

Since 2.6

### g_key_file_get_locale_string ()

    gchar*              g_key_file_get_locale_string        (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             GError **error);

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.

If `key` cannot be found then `NULL` is returned and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. If the value associated with `key` cannot be interpreted or no suitable translation can be found then the untranslated value is returned.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`locale` : | a locale or `NULL`
`error` : | return location for a GError, or `NULL`
Returns : | a newly allocated string or `NULL` if the specified key cannot be found.

Since 2.6

### g_key_file_get_boolean ()

    gboolean            g_key_file_get_boolean              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the value associated with `key` cannot be interpreted as a boolean then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`error` : | return location for a GError
Returns : | the value associated with the key as a boolean

Since 2.6

### g_key_file_get_integer ()

    gint                g_key_file_get_integer              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the value associated with `key` cannot be interpreted as an integer then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`error` : | return location for a GError
Returns : | the value associated with the key as an integer.

Since 2.6

### g_key_file_get_double ()

    gdouble             g_key_file_get_double               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the value associated with `key` cannot be interpreted as a double then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`error` : | return location for a GError
Returns : | the value associated with the key as a double.

Since 2.12

### g_key_file_get_string_list ()

    gchar**             g_key_file_get_string_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);

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

In the event the key cannot be found, `NULL` is returned and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. 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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`length` : | return location for the number of returned strings, or `NULL`
`error` : | return location for a GError, or `NULL`
Returns : | a `NULL`-terminated string array or `NULL` if the specified key cannot be found. The array should be freed with `g_strfreev()`.

Since 2.6

### g_key_file_get_locale_string_list ()

    gchar**             g_key_file_get_locale_string_list   (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             gsize *length,
                                                             GError **error);

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.

If `key` cannot be found then `NULL` is returned and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. If the values associated with `key` cannot be interpreted or no suitable translations can be found then the untranslated values are returned. The returned array is `NULL`-terminated, so `length` may optionally be `NULL`.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`locale` : | a locale
`length` : | return location for the number of returned strings or `NULL`
`error` : | return location for a GError or `NULL`
Returns : | a newly allocated `NULL`-terminated string array or `NULL` if the key isn't found. The string array should be freed with `g_strfreev()`.

Since 2.6

### g_key_file_get_boolean_list ()

    gboolean*           g_key_file_get_boolean_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);

Returns the values associated with `key` under `group_name` as booleans. If `group_name` is `NULL`, the start_group is used.

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the values associated with `key` cannot be interpreted as booleans then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`length` : | the number of booleans returned
`error` : | return location for a GError
Returns : | the values associated with the key as a boolean

Since 2.6

### g_key_file_get_integer_list ()

    gint*               g_key_file_get_integer_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);

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

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the values associated with `key` cannot be interpreted as integers then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`length` : | the number of integers returned
`error` : | return location for a GError
Returns : | the values associated with the key as a integer

Since 2.6

### g_key_file_get_double_list ()

    gdouble*            g_key_file_get_double_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gsize *length,
                                                             GError **error);

Returns the values associated with `key` under `group_name` as doubles. If `group_name` is `NULL`, the start group is used.

If `key` cannot be found then the return value is undefined and `error` is set to G_KEY_FILE_ERROR_KEY_NOT_FOUND. Likewise, if the values associated with `key` cannot be interpreted as doubles then the return value is also undefined and `error` is set to G_KEY_FILE_ERROR_INVALID_VALUE.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`length` : | the number of doubles returned
`error` : | return location for a GError
Returns : | the values associated with the key as a double

Since 2.12

### g_key_file_get_comment ()

    gchar*              g_key_file_get_comment              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name, or `NULL`
`key` : | a key
`error` : | return location for a GError
Returns : | a comment that should be freed with `g_free()`

Since 2.6

### g_key_file_set_value ()

    void                g_key_file_set_value                (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *value);

Associates a new 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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`value` : | a string

Since 2.6

### g_key_file_set_string ()

    void                g_key_file_set_string               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`string` : | a string

Since 2.6

### g_key_file_set_locale_string ()

    void                g_key_file_set_locale_string        (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             const gchar *string);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`locale` : | a locale
`string` : | a string

Since 2.6

### g_key_file_set_boolean ()

    void                g_key_file_set_boolean              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gboolean value);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`value` : | `TRUE` or `FALSE`

Since 2.6

### g_key_file_set_integer ()

    void                g_key_file_set_integer              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gint value);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`value` : | an integer value

Since 2.6

### g_key_file_set_double ()

    void                g_key_file_set_double               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gdouble value);

Associates a new double value with `key` under `group_name`. If `key` cannot be found then it is created. If `group_name` is `NULL`, the start group is used.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`value` : | an double value

Since 2.12

### g_key_file_set_string_list ()

    void                g_key_file_set_string_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar * const list[],
                                                             gsize length);

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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`list` : | an array of locale string values
`length` : | number of locale string values in `list`

Since 2.6

### g_key_file_set_locale_string_list ()

    void                g_key_file_set_locale_string_list   (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *locale,
                                                             const gchar * const list[],
                                                             gsize length);

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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`locale` : | a locale
`list` : | a `NULL`-terminated array of locale string values
`length` : | the length of `list`

Since 2.6

### g_key_file_set_boolean_list ()

    void                g_key_file_set_boolean_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gboolean list[],
                                                             gsize length);

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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`list` : | an array of boolean values
`length` : | length of `list`

Since 2.6

### g_key_file_set_integer_list ()

    void                g_key_file_set_integer_list         (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gint list[],
                                                             gsize length);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`list` : | an array of integer values
`length` : | number of integer values in `list`

Since 2.6

### g_key_file_set_double_list ()

    void                g_key_file_set_double_list          (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             gdouble list[],
                                                             gsize length);

Associates a list of double 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.

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key
`list` : | an array of double values
`length` : | number of double values in `list`

Since 2.12

### g_key_file_set_comment ()

    void                g_key_file_set_comment              (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             const gchar *comment,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name, or `NULL`
`key` : | a key
`comment` : | a comment
`error` : | return location for a GError

Since 2.6

### g_key_file_remove_group ()

    void                g_key_file_remove_group             (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`error` : | return location for a GError or `NULL`

Since 2.6

### g_key_file_remove_key ()

    void                g_key_file_remove_key               (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name
`key` : | a key name to remove
`error` : | return location for a GError or `NULL`

Since 2.6

### g_key_file_remove_comment ()

    void                g_key_file_remove_comment           (GKeyFile *key_file,
                                                             const gchar *group_name,
                                                             const gchar *key,
                                                             GError **error);

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

`key_file` : | a GKeyFile
`group_name` : | a group name, or `NULL`
`key` : | a key
`error` : | return location for a GError

Since 2.6