CATOPEN(3)		   Linux Programmers Manual		   CATOPEN(3)



NAME
       catopen, catclose - open/close a message catalog

SYNOPSIS
       #include 

       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 and 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.

CONFORMING TO
       POSIX.1-2001.  It is unclear what the  source  was  for	the  constants
       MCLoadBySet and MCLoadAll (see below).

NOTES
       The  above  is  the  POSIX.1-2001  description.	 The  glibc  value for
       NL_CAT_LOCALE is 1.   (Compare  MCLoadAll  below.)   The  default  path
       varies,	 but   usually	 looks	 at   a   number   of	places	 below
       /usr/share/locale.

   Linux Notes
       These functions are available for Linux since libc 4.4.4c.  In the case
       of  linux  libc4  and  libc5,  the  catalog  descriptor	nl_catd  is  a
       mmap(2)ed area of memory and not a file descriptor.  The flag argument
       to  catopen() should be either MCLoadBySet (=0) or MCLoadAll (=1).  The
       former value indicates that a set from the catalog is to be loaded when
       needed, whereas the latter causes the initial call to catopen() to load
       the entire catalog into memory.	The default search  path  varies,  but
       usually	 looks	 at   a   number   of  places  below  /etc/locale  and
       /usr/lib/locale.

SEE ALSO
       catgets(3), setlocale(3)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



GNU				  2001-12-14			    CATOPEN(3)