CATOPEN(3)		   Linux Programmer's Manual		    CATOPEN(3)



NAME
       catopen, catclose - open/close a message catalog

SYNOPSIS
       #include <nl_types.h>

       nl_catd catopen(const char *name, int flag);

       int catclose(nl_catd catalog);

DESCRIPTION
       The  function  catopen()	 opens a message catalog and returns a catalog
       descriptor.   The  descriptor  remains  valid   until   catclose()   or
       execve(2).   If a file descriptor is used to implement catalog descrip-
       tors, then the FD_CLOEXEC flag will be set.

       The argument name specifies the name  of	 the  message  catalog	to  be
       opened.	 If  name  specifies  an absolute path (i.e., contains a '/'),
       then name specifies a pathname for the message catalog.	Otherwise, the
       environment  variable NLSPATH is used with name substituted for %N (see
       locale(7)).  It is unspecified whether NLSPATH will be  used  when  the
       process has root privileges.  If NLSPATH does not exist in the environ-
       ment, or if a message catalog cannot be opened  in  any	of  the	 paths
       specified  by  it,  then	 an implementation defined path is used.  This
       latter default path may depend on the LC_MESSAGES locale	 setting  when
       the flag argument is NL_CAT_LOCALE and on the LANG environment variable
       when the flag argument is 0.  Changing  the  LC_MESSAGES	 part  of  the
       locale may invalidate open catalog descriptors.

       The  flag  argument to catopen() is used to indicate the source for the
       language to use.	 If it is set to NL_CAT_LOCALE, then it will  use  the
       current	locale	setting	 for  LC_MESSAGES.  Otherwise, it will use the
       LANG environment variable.

       The function catclose() closes the message catalog identified by	 cata-
       log.   It  invalidates any subsequent references to the message catalog
       defined by catalog.

RETURN VALUE
       The function catopen() returns a message	 catalog  descriptor  of  type
       nl_catd on success.  On failure, it returns (nl_catd) -1 and sets errno
       to indicate the error.  The possible error values include all  possible
       values for the open(2) call.

       The function catclose() returns 0 on success, or -1 on failure.

ENVIRONMENT
       LC_MESSAGES
	      May  be  the  source of the LC_MESSAGES locale setting, and thus
	      determine the language to use if flag is set to NL_CAT_LOCALE.

       LANG   The language to use if flag is 0.

ATTRIBUTES
       For  an	explanation  of	 the  terms  used   in	 this	section,   see
       attributes(7).

       +-----------+---------------+-------------+
       |Interface  | Attribute	   | Value	 |
       +-----------+---------------+-------------+
       |catopen()  | Thread safety | MT-Safe env |
       +-----------+---------------+-------------+
       |catclose() | Thread safety | MT-Safe	 |
       +-----------+---------------+-------------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

NOTES
       The   above   is	  the	POSIX.1	 description.	The  glibc  value  for
       NL_CAT_LOCALE is 1.  The default path varies, but usually  looks	 at  a
       number of places below /usr/share/locale.

SEE ALSO
       catgets(3), setlocale(3)

COLOPHON
       This  page  is  part of release 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest	  version     of     this    page,    can    be	   found    at
       https://www.kernel.org/doc/man-pages/.



GNU				  2015-08-08			    CATOPEN(3)