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

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       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.