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 (consult 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 mes‐
sage catalog descriptor. The name argument specifies the name of the
message catalog to be opened. If name contains a '/', then name speci‐
fies a complete name for the message catalog. Otherwise, the environ‐
ment variable NLSPATH is used with name substituted for the %N conver‐
sion specification (see the Base Definitions volume of POSIX.1‐2008,
Chapter 8, Environment Variables). If NLSPATH exists in the environ‐
ment when the process starts, then if the process has appropriate priv‐
ileges, the behavior of catopen() is undefined. 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
setting 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 exist‐
ing 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 cate‐
gory. 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 POSIX.1‐2008, 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 indi‐
cate 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 mes‐
sage catalog.
EMFILE All file descriptors available to the process are currently
open.
ENAMETOOLONG
The length of a component of a pathname is longer than
{NAME_MAX}.
ENAMETOOLONG
The length of a pathname exceeds {PATH_MAX}, or pathname resolu‐
tion of a symbolic link produced an intermediate result with a
length that 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 names an
existing file that is neither a directory nor a symbolic link to
a directory, or the pathname of the message catalog contains at
least one non-<slash> character and ends with one or more trail‐
ing <slash> characters and the last pathname component names an
existing file that is neither a directory nor a symbolic link to
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 functions.
Application developers 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 ALSOcatclose(), catgets()
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables, <fcntl.h>, <nl_types.h>,
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 CATOPEN(3P)
