CATOPEN(3P)                                         POSIX Programmer's Manual                                        CATOPEN(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       catopen - open a message catalog

SYNOPSIS
       #include <nl_types.h>

       nl_catd catopen(const char *name, int oflag);


DESCRIPTION
       The  catopen() function shall open a message catalog and return a message catalog descriptor. The name argument specifies
       the name of the message catalog to be opened. If name contains a '/', then name specifies a complete name for the message
       catalog.  Otherwise,  the  environment variable NLSPATH is used with name substituted for the %N conversion specification
       (see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 8, Environment Variables). If  NLSPATH  exists  in  the
       environment  when  the process starts, then if the process has appropriate privileges, the behavior of catopen() is unde-
       fined. If NLSPATH does not exist in the environment, or if a message catalog cannot be found in  any  of  the  components
       specified by NLSPATH, then an implementation-defined default path shall be used. This default may be affected by the set-
       ting of LC_MESSAGES if the value of oflag is NL_CAT_LOCALE, or the LANG environment variable if oflag is 0.

       A message catalog descriptor shall remain valid in a process until that process closes it, or a successful call to one of
       the exec functions. A change in the setting of the LC_MESSAGES category may invalidate existing open catalogs.

       If a file descriptor is used to implement message catalog descriptors, the FD_CLOEXEC flag shall be set; see <fcntl.h>.

       If  the  value  of the oflag argument is 0, the LANG environment variable is used to locate the catalog without regard to
       the LC_MESSAGES category. If the oflag argument is NL_CAT_LOCALE, the LC_MESSAGES category is used to locate the  message
       catalog (see the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables).

RETURN VALUE
       Upon  successful completion, catopen() shall return a message catalog descriptor for use on subsequent calls to catgets()
       and catclose(). Otherwise, catopen() shall return ( nl_catd) -1 and set errno to indicate the error.

ERRORS
       The catopen() function may fail if:

       EACCES Search permission is denied for the component of the path prefix of the message  catalog  or  read  permission  is
              denied for the message catalog.

       EMFILE {OPEN_MAX} file descriptors are currently open in the calling process.

       ENAMETOOLONG
              The  length  of  a  pathname  of  the  message  catalog  exceeds {PATH_MAX} or a pathname component is longer than
              {NAME_MAX}.

       ENAMETOOLONG
              Pathname resolution of a symbolic link produced an intermediate result whose length exceeds {PATH_MAX}.

       ENFILE Too many files are currently open in the system.

       ENOENT The message catalog does not exist or the name argument points to an empty string.

       ENOMEM Insufficient storage space is available.

       ENOTDIR
              A component of the path prefix of the message catalog is not a directory.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Some implementations of catopen() use malloc() to allocate space for internal buffer areas. The  catopen()  function  may
       fail if there is insufficient storage space available to accommodate these buffers.

       Conforming  applications must assume that message catalog descriptors are not valid after a call to one of the exec func-
       tions.

       Application writers should be aware that guidelines for the location of message catalogs have  not  yet  been  developed.
       Therefore they should take care to avoid conflicting with catalogs used by other applications and the standard utilities.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       catclose(), catgets(), the Base Definitions volume of IEEE Std 1003.1-2001, <fcntl.h>, <nl_types.h>, the Shell and Utili-
       ties volume of IEEE Std 1003.1-2001

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                   CATOPEN(3P)