Binds the path predicate for a message domainname domainname to
the directory name specified by dirname .
If domainname is a non-empty string and has not been bound
previously, bindtextdomain() binds domainname with dirname .
If domainname is a non-empty string and has been bound previously,
bindtextdomain() replaces the old binding with dirname .
The dirname argument can be an absolute or relative pathname
being resolved when gettext() , dgettext() or dcgettext()
are called.
If domainname is zero or an empty string, bindtextdomain()
returns 0.
User defined domain names cannot begin with the string "SYS_"
.
Domain names beginning with this string are reserved for system use.