1CATOPEN(3) Linux Programmer's Manual CATOPEN(3)
2
6 catopen, catclose - open/close a message catalog
7
9 #include <nl_types.h>
10 nl_catd catopen(const char *name, int flag);
12 int catclose(nl_catd catalog);
14
16 The function catopen() opens a message catalog and returns a catalog
17 descriptor. The descriptor remains valid until catclose() or
18 execve(2). If a file descriptor is used to implement catalog descrip‐
19 tors then the FD_CLOEXEC flag will be set.
20 The argument name specifies the name of the message catalog to be
22 opened. If name specifies and absolute path (i.e., contains a '/'),
23 then name specifies a pathname for the message catalog. Otherwise, the
24 environment variable NLSPATH is used with name substituted for %N (see
25 locale(7)). It is unspecified whether NLSPATH will be used when the
26 process has root privileges. If NLSPATH does not exist in the environ‐
27 ment, or if a message catalog cannot be opened in any of the paths
28 specified by it, then an implementation defined path is used. This
29 latter default path may depend on the LC_MESSAGES locale setting when
30 the flag argument is NL_CAT_LOCALE and on the LANG environment variable
31 when the flag argument is 0. Changing the LC_MESSAGES part of the
32 locale may invalidate open catalog descriptors.
33 The flag argument to catopen() is used to indicate the source for the
35 language to use. If it is set to NL_CAT_LOCALE then it will use the
36 current locale setting for LC_MESSAGES. Otherwise it will use the LANG
37 environment variable.
38 The function catclose() closes the message catalog identified by cata‐
40 log. It invalidates any subsequent references to the message catalog
41 defined by catalog.
42
44 The function catopen() returns a message catalog descriptor of type
45 nl_catd on success. On failure, it returns (nl_catd) -1 and sets errno
46 to indicate the error. The possible error values include all possible
47 values for the open(2) call.
48 The function catclose() returns 0 on success, or -1 on failure.
50
52 LC_MESSAGES
53 May be the source of the LC_MESSAGES locale setting, and thus
54 determine the language to use if flag is set to NL_CAT_LOCALE.
55 LANG The language to use if flag is 0.
57
59 POSIX.1-2001. It is unclear what the source was for the constants
60 MCLoadBySet and MCLoadAll (see below).
61
63 The above is the POSIX.1-2001 description. The glibc value for
64 NL_CAT_LOCALE is 1. (Compare MCLoadAll below.) The default path
65 varies, but usually looks at a number of places below
66 /usr/share/locale.
67 Linux Notes
69 These functions are available for Linux since libc 4.4.4c. In the case
70 of linux libc4 and libc5, the catalog descriptor nl_catd is a
71 mmap(2)'ed area of memory and not a file descriptor. The flag argument
72 to catopen() should be either MCLoadBySet (=0) or MCLoadAll (=1). The
73 former value indicates that a set from the catalog is to be loaded when
74 needed, whereas the latter causes the initial call to catopen() to load
75 the entire catalog into memory. The default search path varies, but
76 usually looks at a number of places below /etc/locale and
77 /usr/lib/locale.
78
80 catgets(3), setlocale(3)
81
83 This page is part of release 3.22 of the Linux man-pages project. A
84 description of the project, and information about reporting bugs, can
85 be found at http://www.kernel.org/doc/man-pages/.
86GNU 2001-12-14 CATOPEN(3)