catopen, catclose-open/close a message catalogue
#include <nl_types.h>
nl_catd catopen (char *name, int oflag)
int catclose (nl_catd catd)
catopen opens a message catalogue and returns a catalogue descriptor. name specifies the name of the message catalogue to be opened. If name contains a "/" then name specifies a pathname for the message catalogue. Otherwise, the environment variable NLSPATH is used. If NLSPATH does not exist in the environment, or if a message catalogue cannot be opened in any of the paths specified by NLSPATH, then the default path is used (see nl_types(5)).
The names of message catalogues, and their location in the filestore, can vary from one system to another. Individual applications can choose to name or locate message catalogues according to their own special needs. A mechanism is therefore required to specify where the catalogue resides.
The NLSPATH variable provides both the location of message catalogues, in the form of a search path, and the naming conventions associated with message catalogue files. For example:
NLSPATH=/nlslib/%L/%N.cat:/nlslib/%N/%L
The metacharacter % introduces a substitution field, where %L substitutes the current setting of the LANG environment variable (see following section), and %N substitutes the value of the name parameter passed to catopen. Thus, in the above example, catopen will search in /nlslib/$LANG/name.cat, then in /nlslib/name/$LANG, for the required message catalogue.
NLSPATH will normally be set up on a system wide basis (e.g., in /etc/profile) and thus makes the location and naming conventions associated with message catalogues transparent to both programs and users.
The full set of metacharacters is:
The A user who speaks German as it is spoken in Austria and has a terminal that operates in ISO 8859/1 codeset, would want the setting of the With this setting it should be possible for the user to find relevant catalogues if they exist.
If the If successful, LANG environment variable provides the ability to specify the user's requirements for native languages, local customs and character set, as an ASCII string in the form LANG=language[_territory[.codeset]]
LANG variable to be as follows:
LANG=De_A.88591
LANG variable is not set then the value of LC_MESSAGES as returned by setlocale(3) is used. If this is NULL then the default path as defined in nl_types(5) is used.
oflag is reserved for future use and should be set to 0. The results of setting this field to any other value are undefined.
catclose closes the message catalogue identified by catd.
Diagnostics
catopen returns a message catalogue descriptor for use on subsequent calls to catgets(3) and catclose(3). Otherwise catopen() returns (nl_catd) -1. catclose returns 0 if successful, otherwise -1.
See Also
catgets(3), setlocale(3), nl_types(5).