catopen(3C)catopen(3C)NAME
catopen, catclose - open/close a message catalogue
SYNOPSIS
#include <nl_types.h>
nl_catd catopen (const char *name, int oflag);
int catclose (nl_catd catd);
DESCRIPTIONcatopen opens a message catalogue and returns a catalogue descriptor.
name specifies the name of the message catalogue to be opened. If name
contains a ``/'' then name specifies a pathname for the message
catalogue. Otherwise, the environment variable NLSPATH is used. If
NLSPATH does not exist in the environment, or if a message catalogue
cannot be opened in any of the paths specified by NLSPATH, then the
default path is used [see nl_types(5)].
The names of message catalogues, and their location in the filestore, can
vary from one system to another. Individual applications can choose to
name or locate message catalogues according to their own special needs.
A mechanism is therefore required to specify where the catalogue resides.
The NLSPATH variable provides both the location of message catalogues, in
the form of a search path, and the naming conventions associated with
message catalogue files. For example:
NLSPATH=/nlslib/%L/%N.cat:/nlslib/%N/%L
The metacharacter % introduces a substitution field, where %L substitutes
the current setting of the LANG environment variable if oflag is 0 or the
current setting of the LC_MESSAGES category if oflag is NL_CAT_LOCALE
(see following section), and %N substitutes the value of the name
parameter passed to catopen. Thus, in the above example, if oflag is 0,
catopen will search in /nlslib/$LANG/name.cat, then in
/nlslib/name/$LANG, for the required message catalogue.
NLSPATH will normally be set up on a system wide basis (e.g., in
/etc/profile) and thus makes the location and naming conventions
associated with message catalogues transparent to both programs and
users.
Security dictates that catopen does not honor the NLSPATH environment
variable for setuid and setgid programs.
The full set of metacharacters is:
%N The value of the name parameter passed to catopen.
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catopen(3C)catopen(3C)
%L The value of LANG environment variable if oflag is 0. The
value of LC_MESSAGES category if oflag is NL_CAT_LOCALE.
%l The value of the language element of LANG environment variable
if oflag is 0. The value of the language element of
LC_MESSAGES category if oflag is NL_CAT_LOCALE.
%t The value of the territory element of LANG environment variable
if oflag is 0. The value of the territory element of
LC_MESSAGES category if oflag is NL_CAT_LOCALE.
%c The value of the codeset element of LANG environment variable
if oflag is 0. The value of the codeset element of LC_MESSAGES
category if oflag is NL_CAT_LOCALE.
%% A single %.
The LANG environment variable provides the ability to specify the user's
requirements for native languages, local customs, and character set, as
an ASCII string in the form
LANG=language[_territory[.codeset]]
A user who speaks German as it is spoken in Austria and has a terminal
which operates in ISO 8859/1 codeset, would want the setting of the LANG
variable to be
LANG=De_A.88591
With this setting it should be possible for that user to find any
relevant catalogues should they exist.
If it still can't find the catalogue file, then the default path as
defined in nl_types is used.
oflag is used to locate the catalogue file. If oflag is 0, the LANG
environment variable is used to locate it. If oflag is set to
NL_CAT_LOCALE, the LC_MESSAGES category is used to locate the catalogue
file. The results of setting this field to any other value are
undefined.
catclose closes the message catalogue identified by catd.
SEE ALSOcatgets(3C), setlocale(3C), environ(5), nl_types(5).
DIAGNOSTICS
If successful, catopen returns a message catalogue descriptor for use in
subsequent calls to catgets and catclose. Otherwise catopen returns
(nl_catd) -1.
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catopen(3C)catopen(3C)
catclose returns 0 if successful, otherwise -1.
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