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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).

     allbox;  lb  lb  lb  l  l  l.   Interface Attribute Value  T{ catopen()
     T}   Thread   safety     MT-Safe   env   T{   catclose()    T}   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.