Open Source Software

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
   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  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
   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.

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 4.09 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/.



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