1catopen(3) Library Functions Manual catopen(3)
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6 catopen, catclose - open/close a message catalog
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9 Standard C library (libc, -lc)
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12 #include <nl_types.h>
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14 nl_catd catopen(const char *name, int flag);
15 int catclose(nl_catd catalog);
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18 The function catopen() opens a message catalog and returns a catalog
19 descriptor. The descriptor remains valid until catclose() or ex‐
20 ecve(2). If a file descriptor is used to implement catalog descrip‐
21 tors, then the FD_CLOEXEC flag will be set.
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23 The argument name specifies the name of the message catalog to be
24 opened. If name specifies an absolute path (i.e., contains a '/'),
25 then name specifies a pathname for the message catalog. Otherwise, the
26 environment variable NLSPATH is used with name substituted for %N (see
27 locale(7)). It is unspecified whether NLSPATH will be used when the
28 process has root privileges. If NLSPATH does not exist in the environ‐
29 ment, or if a message catalog cannot be opened in any of the paths
30 specified by it, then an implementation defined path is used. This
31 latter default path may depend on the LC_MESSAGES locale setting when
32 the flag argument is NL_CAT_LOCALE and on the LANG environment variable
33 when the flag argument is 0. Changing the LC_MESSAGES part of the lo‐
34 cale may invalidate open catalog descriptors.
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36 The flag argument to catopen() is used to indicate the source for the
37 language to use. If it is set to NL_CAT_LOCALE, then it will use the
38 current locale setting for LC_MESSAGES. Otherwise, it will use the
39 LANG environment variable.
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41 The function catclose() closes the message catalog identified by cata‐
42 log. It invalidates any subsequent references to the message catalog
43 defined by catalog.
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46 The function catopen() returns a message catalog descriptor of type
47 nl_catd on success. On failure, it returns (nl_catd) -1 and sets errno
48 to indicate the error. The possible error values include all possible
49 values for the open(2) call.
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51 The function catclose() returns 0 on success, or -1 on failure.
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54 LC_MESSAGES
55 May be the source of the LC_MESSAGES locale setting, and thus
56 determine the language to use if flag is set to NL_CAT_LOCALE.
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58 LANG The language to use if flag is 0.
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61 For an explanation of the terms used in this section, see at‐
62 tributes(7).
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64 ┌────────────────────────────────────────┬───────────────┬─────────────┐
65 │Interface │ Attribute │ Value │
66 ├────────────────────────────────────────┼───────────────┼─────────────┤
67 │catopen() │ Thread safety │ MT-Safe env │
68 ├────────────────────────────────────────┼───────────────┼─────────────┤
69 │catclose() │ Thread safety │ MT-Safe │
70 └────────────────────────────────────────┴───────────────┴─────────────┘
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73 The above is the POSIX.1 description. The glibc value for NL_CAT_LO‐
74 CALE is 1. The default path varies, but usually looks at a number of
75 places below /usr/share/locale.
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78 POSIX.1-2008.
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81 POSIX.1-2001.
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84 catgets(3), setlocale(3)
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88Linux man-pages 6.04 2023-03-30 catopen(3)