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 descriptors  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
       environment, 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 catalog.  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 3.54 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)