1catopen(3C) Standard C Library Functions catopen(3C)
2
6 catopen, catclose - open/close a message catalog
7
9 #include <nl_types.h>
10 nl_catd catopen(const char *name, int oflag);
12 int catclose(nl_catd catd);
15
18 The catopen() function opens a message catalog and returns a message
19 catalog descriptor. name specifies the name of the message catalog to
20 be opened. If name contains a "/", then name specifies a complete
21 pathname for the message catalog; otherwise, the environment variable
22 NLSPATH is used and /usr/lib/locale/locale/LC_MESSAGES must exist. If
23 NLSPATH does not exist in the environment, or if a message catalog can‐
24 not be opened in any of the paths specified by NLSPATH, then the
25 default path /usr/lib/locale/locale/LC_MESSAGES is used. In the "C"
26 locale, catopen() will always succeed without checking the default
27 search path.
28 The names of message catalogs and their location in the filesystem can
31 vary from one system to another. Individual applications can choose to
32 name or locate message catalogs according to their own special needs. A
33 mechanism is therefore required to specify where the catalog resides.
34 The NLSPATH variable provides both the location of message catalogs, in
37 the form of a search path, and the naming conventions associated with
38 message catalog files. For example:
39 NLSPATH=/nlslib/%L/%N.cat:/nlslib/%N/%L
41 The metacharacter % introduces a substitution field, where %L substi‐
45 tutes the current setting of either the LANG environment variable, if
46 the value of oflag is 0, or the LC_MESSAGES category, if the value of
47 oflag is NL_CAT_LOCALE, and %N substitutes the value of the name
48 parameter passed to catopen(). Thus, in the above example, catopen()
49 will search in /nlslib/$LANG/name.cat, if oflag is 0, or in
50 /nlslib/{LC_MESSAGES}/name.cat, if oflag is NL_CAT_LOCALE.
51 The NLSPATH variable will normally be set up on a system wide basis (in
54 /etc/profile) and thus makes the location and naming conventions asso‐
55 ciated with message catalogs transparent to both programs and users.
56 The full set of metacharacters is:
59 %N The value of the name parameter passed to catopen().
61 %L The value of LANG or LC_MESSAGES.
64 %l The value of the language element of LANG or LC_MESSAGES.
67 %t The value of the territory element of LANG or LC_MESSAGES.
70 %c The value of the codeset element of LANG or LC_MESSAGES.
73 %% A single %.
76 The LANG environment variable provides the ability to specify the
80 user's requirements for native languages, local customs and character
81 set, as an ASCII string in the form
82 LANG=language[_territory[.codeset]]
84 A user who speaks German as it is spoken in Austria and has a terminal
88 which operates in ISO 8859/1 codeset, would want the setting of the
89 LANG variable to be
90 LANG=De_A.88591
92 With this setting it should be possible for that user to find any rel‐
96 evant catalogs should they exist.
97 Should the LANG variable not be set, the value of LC_MESSAGES as
100 returned by setlocale() is used. If this is NULL, the default path as
101 defined in <nl_types.h> is used.
102 A message catalogue descriptor remains valid in a process until that
105 process closes it, or a successful call to one of the exec functions. A
106 change in the setting of the LC_MESSAGES category may invalidate exist‐
107 ing open catalogues.
108 If a file descriptor is used to implement message catalogue descrip‐
111 tors, the FD_CLOEXEC flag will be set; see <fcntl.h>.
112 If the value of oflag argument is 0, the LANG environment variable is
115 used to locate the catalogue without regard to the LC_MESSAGES cate‐
116 gory. If the oflag argument is NL_CAT_LOCALE, the LC_MESSAGES category
117 is used to locate the message catalogue.
118 The catclose() function closes the message catalog identified by catd.
121 If a file descriptor is used to implement the type nl_catd, that file
122 descriptor will be closed.
123
125 Upon successful completion, catopen() returns a message catalog
126 descriptor for use on subsequent calls to catgets() and catclose().
127 Otherwise it returns (nl_catd) −1.
128 Upon successful completion, catclose() returns 0. Otherwise it returns
131 −1 and sets errno to indicate the error.
132
134 The catopen() function may fail if:
135 EACCES Search permission is denied for the component of the
137 path prefix of the message catalogue or read permission
138 is denied for the message catalogue.
139 EMFILE There are OPEN_MAX file descriptors currently open in
142 the calling process.
143 ENAMETOOLONG The length of the pathname of the message catalogue
146 exceeds PATH_MAX, or a pathname component is longer
147 than NAME_MAX.
148 ENAMETOOLONG Pathname resolution of a symbolic link produced an
151 intermediate result whose length exceeds PATH_MAX.
152 ENFILE Too many files are currently open in the system.
155 ENOENT The message catalogue does not exist or the name argu‐
158 ment points to an empty string.
159 ENOMEM Insufficient storage space is available.
162 ENOTDIR A component of the path prefix of the message catalogue
165 is not a directory.
166 The catclose() function may fail if:
170 EBADF The catalogue descriptor is not valid.
172 EINTR The catclose() function was interrupted by a signal.
175
178 The catopen() and catclose() functions can be used safely in multi‐
179 threaded applications, as long as setlocale(3C) is not being called to
180 change the locale.
181
183 See attributes(5) for descriptions of the following attributes:
184 ┌─────────────────────────────┬─────────────────────────────┐
189 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
190 ├─────────────────────────────┼─────────────────────────────┤
191 │Interface Stability │Standard │
192 ├─────────────────────────────┼─────────────────────────────┤
193 │MT-Level │MT-Safe │
194 └─────────────────────────────┴─────────────────────────────┘
195
197 gencat(1), catgets(3C), gettext(3C), nl_types.h(3HEAD), setlocale(3C),
198 attributes(5), environ(5)
199SunOS 5.11 29 Dec 1996 catopen(3C)