osx man page for set_config_string

set_config_string(3alleg4)					  Allegro manual					set_config_string(3alleg4)

NAME
       set_config_string - Writes a string in the configuration file. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       void set_config_string(const char *section, const char *name, const char *val);

DESCRIPTION
       Writes  a  string  variable to the current config file, replacing any existing value it may have, or removes the variable if `val' is NULL.
       The section name may be set to NULL to write the variable to the root of the file, or  used  to	control  which	section  the  variable	is
       inserted into. The altered file will be cached in memory, and not actually written to disk until you call allegro_exit(). Note that you can
       only write to files in this way, so the function will have no effect if the current config  source  was	specified  with  set_config_data()
       rather than set_config_file().

       As  a special case, variable or section names that begin with a '#' character are treated specially and will not be read from or written to
       the disk. Addon packages can use this to store version info or other status information into the config module, from where it can  be  read
       with the get_config_string() function.

SEE ALSO
       set_config_file(3alleg4), get_config_string(3alleg4), set_config_float(3alleg4), set_config_hex(3alleg4), set_config_int(3alleg4), set_con-
       fig_id(3alleg4)

Allegro 							   version 4.4.2					set_config_string(3alleg4)