While this single name domain works well for most applications there
might be the need to get translations from more than one domain. Of
course one could switch between different domains with calls to
textdomain, but this is really not convenient nor is it fast. A
possible situation could be one case subject to discussion during this
error messages of functions in the set of common used functions should
go into a separate domain
error. By this mean we would only need
to translate them once.
Another case are messages from a library, as these have to be
independent of the current domain set by the application.
For this reasons there are two more functions to retrieve strings:
char *dgettext (const char *domain_name, const char *msgid); char *dcgettext (const char *domain_name, const char *msgid, int category);
Both take an additional argument at the first place, which corresponds
to the argument of
textdomain. The third argument of
dcgettext allows to use another locale category but
But I really don’t know where this can be useful. If the
NULL or category has an value beside
the known ones, the result is undefined. It should also be noted that
this function is not part of the second known implementation of this
function family, the one found in Solaris.
A second ambiguity can arise by the fact, that perhaps more than one domain has the same name. This can be solved by specifying where the needed message catalog files can be found.
char *bindtextdomain (const char *domain_name, const char *dir_name);
Calling this function binds the given domain to a file in the specified
directory (how this file is determined follows below). Especially a
file in the systems default place is not favored against the specified
file anymore (as it would be by solely using
NULL pointer for the dir_name parameter returns the binding
associated with domain_name. If domain_name itself is
NULL nothing happens and a
NULL pointer is returned. Here
again as for all the other functions is true that none of the return
value must be changed!
It is important to remember that relative path names for the
dir_name parameter can be trouble. Since the path is always
computed relative to the current directory different results will be
achieved when the program executes a
chdir command. Relative
paths should always be avoided to avoid dependencies and