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### 5.7 libcfg

#### 5.7.1 Overview

View lcov test coverage results on http://www.gnu.org/software/liquidwar6/coverage/src/lib/cfg/index.html.

#### 5.7.2 API

— Function: int lw6cfg_parse_command_line (void * context)

> context: opaque pointer on a context

> Overwrites any existing option with command line args

> Return value: 1 if success, 0 if error

— Function: int lw6cfg_defaults (void * context)

> context: opaque pointer on a context

> Sets all values to their defaults.

> Return value: 1 if success, 0 if error

— Function: int lw6cfg_merge_env (void * cfg_context)

> cfg_context: a context returned by `lw6cfg_init`

> Overwrites any existing vale in the config with environment variables prefixed by LW6_.

> Return value: 1 if successfull, 0 if error.

— Function: int lw6cfg_load_exp (char * user_dir, int * exp)

> user_dir: the user directory

> exp: the exp (out param)

> Gets exp from file.

> Return value: 1 on success, 0 on failure

— Function: int lw6cfg_save_exp (char * user_dir, int exp)

> user_dir: the user directory

> exp: the exp

> Saves exp to file.

> Return value: 1 on success, 0 on failure

— Function: char * lw6cfg_format (char * key, char * value, lw6hlp_type_t type)

> key: the key of the value to format

> value: the value to format

> type: the type of the value to format

> Formats, converts, a given value to its cannonical representation. Booleans will be converted to true/false, strings containing integers will be stripped from junk, and so on. This is a performance killer but will ensure everything is correct.

> Return value: a newly allocated string, containing the same as the input, but reformatted the pedantic way.

— Function: char * lw6cfg_format_guess_type (char * key, char * value)

> key: the key of the value to format

> value: the value to format

> Formats, converts, a given value to its cannonical representation. Booleans will be converted to true/false, strings containing integers will be stripped from junk, and so on. This is a performance killer but will ensure everything is correct. This function will automatically guess the type of the value from its description in the help system.

> Return value: a newly allocated string, containing the same as the input, but reformatted the pedantic way.

— Function: int lw6cfg_load (void * cfg_context, char * filename)

> cfg_context: a context returned by `lw6cfg_init`

> filename: a file path, absolute or relative

> Loads the given config file, and stores its values into the current context. Parameters which are both in the config file and given as command line parameters, will be taken from the command-line.

> Return value: 1 if successfull, 0 if error.

— Function: int lw6cfg_option_exists (void * context, char * key)

> context: context to query

> key: key to search

> Returns wether a key exists within context or not.

> Return value: 1 if exists, 0 if not

— Function: char * lw6cfg_get_option (void * context, char * key)

> context: context to query

> key: key to search

> Returns the current value for a given query, the returned value is always a string, typically the string one would pass on the command line or set in a config file

> Return value: pointer to string, must not be freed.

— Function: void lw6cfg_set_option (void * context, char * key, char * value)

> context: context to modify

> key: key to search and change

> value: new value

> Sets a given key to the specified value, this is a string only function, pass the value you would pass on the command line or set in a config file.

> Return value: none

— Function: int lw6cfg_get_option_int (void * context, char * key)

> context: context to query

> key: key to search

> Returns an option as an integer. Note that this function does not know wether the parameter should really be an integer or not, so you can call it even on non-integer values, but of course results will have no real meaning.

> Return value: option value converted to int

— Function: void lw6cfg_set_option_int (void * context, char * key, int value)

> context: context to modify

> key: key to search and change

> value: new value

> Set a config option to an integer value. Note that this function does not know wether the parameter should really be an integer or not, so you can call it even on non-integer values, at your own risk.

> Return value: none.

— Function: int lw6cfg_get_option_bool (void * context, char * key)

> context: context to query

> key: key to search

> Returns an option as a boolean. Note that this function does not know wether the parameter should really be a boolean or not, so you can call it even on non-boolean values, but of course results will have no real meaning.

> Return value: option value converted to boolean

— Function: void lw6cfg_set_option_bool (void * context, char * key, int value)

> context: context to modify

> key: key to search and change

> value: new value

> Set a config option to a boolean value. Note that this function does not know wether the parameter should really be a boolean or not, so you can call it even on non-boolean values, at your own risk.

> Return value: none.

— Function: int lw6cfg_must_be_saved (char * key)

> key: key to test

> Tells wether a key should be saved in the config file. Typically, some options you don't want to savem such as the location of the config file itself. Most of those non-savable parameters are path-related. This does not mean no paths are saved in the config file.

> Return value: 1 if must be saved, 0 if not

— Function: int lw6cfg_save (void * cfg_context, char * filename)

> cfg_context: a context returned by `lw6cfg_init`

> filename: a file path, absolute or relative

> Save current options into the given config file. Before saving the file, all command line arguments will be read and will override current values. This means the saved file will contain values given as command line arguments.

> Return value: 1 if successfull, 0 if error.

— Function: void * lw6cfg_init (int argc, char * [] argv)

> argc: number of command line arguments, as given to `main`

> argv: a list of command line arguments, as given to `main`

> Initializes a config context object. This object is hidden behind an opaque void * pointer to avoid direct access to its elements.

> Return value: an opaque pointer, must be freed with `lw6cfg_quit`.

— Function: void lw6cfg_quit (void * cfg_context)

> cfg_context: a context returned by `lw6cfg_init`

> Frees a config cfg_context object. You must call this once you're done with the context.

> Return value: none.

— Function: void lw6cfg_reset (int argc, char * [] argv)

> argc: number of command line arguments, as given to `main`

> argv: a list of command line arguments, as given to `main`

> Overwrites the config file with defaults. Use this to get rid of old configurations.

— Function: int lw6cfg_test (int mode)

> mode: 0 for check only, 1 for full test

> Runs the `cfg` module test suite.

> Return value: 1 if test is successfull, 0 on error.

— Function: char * lw6cfg_unified_get_value (int argc, char * [] argv, char * key)

> argc: number of command-line args, as passed to `main`

> argv: arry of command-line args, as passed to `main`

> key: the key to query

> Unified "value" getter, which gets informations from environment variables, command line, and config file. The rules is that the command-line argument always has the last word. It will override any other value. Follows environment variables, which will be used if no command-line argument is supplied. Note that these are "LW6_" prefixed and uppercased environment variables as opposed to lowercased and "dash-separated" keys. Finally, if there's no environment variable, nor any config-file corresponding entry, the value will be searched in the config file. If there's no information in the config file, NULL is returned.

> Return value: a string with the value. Can be NULL. Must be freed.

— Function: char * lw6cfg_unified_get_user_dir (int argc, char * [] argv)

> argc: number of command-line args, as passed to `main`

> argv: arry of command-line args, as passed to `main`

> Gets the user dir, taking all parameters in account, that's to say the "LW6_USER_DIR" env value, the "–user-dir" command-line paramater and the LW6DEF_USER_DIR config file entry.

> Return value: the directory path, might be NULL, must be freed.

— Function: char * lw6cfg_unified_get_log_file (int argc, char * [] argv)

> argc: number of command-line args, as passed to `main`

> argv: arry of command-line args, as passed to `main`

> Gets the log file, taking all parameters in account, that's to say the "LW6_LOG_FILE" env value, the "–log-file" command-line paramater and the LW6DEF_LOG_FILE config file entry.

> Return value: the directory path, might be NULL, must be freed.

— Function: char * lw6cfg_unified_get_music_path (int argc, char * [] argv)

> argc: number of command-line args, as passed to `main`

> argv: arry of command-line args, as passed to `main`

> Gets the user dir, taking all parameters in account, that's to say the "LW6_MUSIC_PATH" env value, the "–music-path" command-line paramater and the LW6DEF_MUSIC_PATH config file entry.

> Return value: the directory path, might be NULL, must be freed.

— Function: char * lw6cfg_unified_get_map_path (int argc, char * [] argv)

> argc: number of command-line args, as passed to `main`

> argv: arry of command-line args, as passed to `main`

> Gets the user dir, taking all parameters in account, that's to say the "LW6_MAP_PATH" env value, the "–map-path" command-line paramater and the LW6DEF_MAP_PATH config file entry.

> Return value: the directory path, might be NULL, must be freed.

— Function: char * lw6cfg_xml_element (lw6hlp_type_t type)

> type: type as an enum

> Returns the string corresponding to a given type, suitable for use in XML files. For instance if you pass `LW6HLP_TYPE_INT` then you will obtain the string int (string of 3 chars containing i, n and t.

> Return value: string, must not be freed.

— Function: void lw6cfg_read_xml_int (char * xml_key, char * xml_value, char * target_key, int * value)

> xml_key: key found in XML file

> xml_value: value found in XML file

> target_key: key we're searching for

> value: the value if found (out param)

> Tries to find a value in a key/value pair. If `xml_key` and `target_key` match, then will put the corresponding value (converted to int) in the `value` param. Typically, you would call this in a loop on every single entry found in an XML file, in an expat callback.

> Return value: none.

— Function: void lw6cfg_read_xml_bool (char * xml_key, char * xml_value, char * target_key, int * value)

> xml_key: key found in XML file

> xml_value: value found in XML file

> target_key: key we're searching for

> value: the value if found (out param)

> Tries to find a value in a key/value pair. If `xml_key` and `target_key` match, then will put the corresponding value (converted to boolean) in the `value` param. Typically, you would call this in a loop on every single entry found in an XML file, in an expat callback.

> Return value: none.

— Function: void lw6cfg_read_xml_float (char * xml_key, char * xml_value, char * target_key, float * value)

> xml_key: key found in XML file

> xml_value: value found in XML file

> target_key: key we're searching for

> value: the value if found (out param)

> Tries to find a value in a key/value pair. If `xml_key` and `target_key` match, then will put the corresponding value (converted to float) in the `value` param. Typically, you would call this in a loop on every single entry found in an XML file, in an expat callback.

> Return value: none.

— Function: void lw6cfg_read_xml_string (char * xml_key, char * xml_value, char * target_key, char ** value)

> xml_key: key found in XML file

> xml_value: value found in XML file

> target_key: key we're searching for

> value: the value if found (out param)

> Tries to find a value in a key/value pair. If `xml_key` and `target_key` match, then will put the corresponding value (as a string) in the `value` param. Typically, you would call this in a loop on every single entry found in an XML file, in an expat callback.

> Return value: none.

— Function: void lw6cfg_read_xml_color (char * xml_key, char * xml_value, char * target_key, lw6sys_color_8_t * value)

> xml_key: key found in XML file

> xml_value: value found in XML file

> target_key: key we're searching for

> value: the value if found (out param)

> Tries to find a value in a key/value pair. If `xml_key` and `target_key` match, then will put the corresponding value (converted to a color) in the `value` param. Typically, you would call this in a loop on every single entry found in an XML file, in an expat callback.

> Return value: none.

— Function: int lw6cfg_read_key_value_xml_file (char * filename, lw6cfg_read_xml_callback_func_t callback_func, void * callback_data)

> filename: full path of file to read

> callback_func: callback function to be called on each element

> callback_data: additionnal pointer passed to callback function

> Will parse a file and call the given callback on each element. This is an over-simplified way to read XML file, in fact we just explain plain non-nested simple elements but this is exactly what LW config files are made of.

> Return value: 1 on success, 0 on failure.

— Function: void lw6cfg_write_xml_int (FILE * f, char * key, int value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes an int entry into an opened XML file.

> Return value: none.

— Function: void lw6cfg_write_xml_bool (FILE * f, char * key, int value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes a boolean entry into an opened XML file.

> Return value: none.

— Function: void lw6cfg_write_xml_float (FILE * f, char * key, float value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes a float entry into an opened XML file.

> Return value: none.

— Function: void lw6cfg_write_xml_string (FILE * f, char * key, char * value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes a string entry into an opened XML file.

> Return value: none.

— Function: void lw6cfg_write_xml_color (FILE * f, char * key, lw6sys_color_8_t value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes a color entry into an opened XML file.

> Return value: none.

— Function: void lw6cfg_write_xml_guess_type (FILE * f, char * key, char * value)

> f: file to write data to (append mode)

> key: key to write

> value: value to write

> Writes an entry into an opened XML file, will try and guess type from the internal help system, typically, if this is a standard config file entry (the one documented by the about command line function) it will pick up the right type. The reason not to use this all the times is that sometimes, one might to to store non-standard options, and additionnally, guessing the type does consume some CPU.

> Return value: none.