#include <nl_types.h>
char *catgets(nl_catd catalog, int set_number, int message_number, const char *message);
catgets() reads the message message_number, in set set_number, from the message catalog identified by catalog, where catalog is a catalog descriptor returned from an earlier call to catopen(3). The fourth argument message points to a default message string which will be returned by catgets() if the identified message catalog is not currently available. The message-text is contained in an internal buffer area and should be copied by the application if it is to be saved or modified. The return string is always terminated with a null byte.
On success, catgets() returns a pointer to an internal buffer area containing the null-terminated message string. On failure, catgets() returns the value message.