#include <pfmt.h>char setcat(const char catalog);
catalog must be limited to 14 characters. These characters must be selected from a set of all characters values, excluding \0 (null) and the ASCII codes for / (slash) and : (colon).
setcat assumes that the catalog exists. No checking is done on the argument.
A null pointer passed as an argument will result in the return of a pointer to the current default message catalog name. A pointer to an empty string passed as an argument will cancel the default catalog.
If no default catalog is specified, or if catalog is an invalid catalog name, subsequent calls to gettxt or pfmt that do not explicitly specify a catalog name will use
Message not found!!\n
as the default string.