catopen(3C)                                                     catopen(3C)


   NAME
         catopen, catclose - open/close a message catalogue

   SYNOPSIS
         #include <nl_types.h>

         nl_catd catopen (char *name, int oflag);

         int catclose (nl_catd catd);

   DESCRIPTION
         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 catalog.

         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:

               %N   The value of the name parameter passed to catopen.

               %L   The value of LANG.





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   catopen(3C)                                                     catopen(3C)


               %l   The value of the language element of LANG.

               %t   The value of the territory element of LANG.

               %c   The value of the codeset element of LANG.

               %%   A single %.

         The LANG environment variable provides the ability to specify the
         users requirements for native languages, local customs and character
         set, as an ASCII string in the form

               LANG=language[_territory[.codeset]]

         A user who speaks German as it is spoken in Austria and has a
         terminal which operates in ISO 8859/1 codeset, would want the setting
         of the LANG variable to be

               LANG=De_A.88591

         With this setting it should be possible for that user to find any
         relevant catalogs should they exist.

         Should the LANG variable not be set then the value of LC_MESSAGES as
         returned by setlocale is used.  If this is NULL then the default path
         as defined in nl_types 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 catalog identified by catd.

   SEE ALSO
         catgets(3C), setlocale(3C), environ(5), nl_types(5).

   DIAGNOSTICS
         If successful, catopen returns a message catalog descriptor for use
         on subsequent calls to catgets and catclose.  Otherwise catopen
         returns (nl_catd) -1.

         catclose returns 0 if successful, otherwise -1.












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