catopen(3)

1CATOPEN(3)                 Linux Programmer's Manual                CATOPEN(3)
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NAME

6       catopen, catclose - open/close a message catalog
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SYNOPSIS

9       #include <nl_types.h>
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11       nl_catd catopen(const char *name, int flag);
12       int catclose(nl_catd catalog);
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DESCRIPTION

15       The  function  catopen()  opens a message catalog and returns a catalog
16       descriptor.  The descriptor  remains  valid  until  catclose()  or  ex‐
17       ecve(2).   If  a  file descriptor is used to implement catalog descrip‐
18       tors, then the FD_CLOEXEC flag will be set.
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20       The argument name specifies the name  of  the  message  catalog  to  be
21       opened.   If  name  specifies  an absolute path (i.e., contains a '/'),
22       then name specifies a pathname for the message catalog.  Otherwise, the
23       environment  variable NLSPATH is used with name substituted for %N (see
24       locale(7)).  It is unspecified whether NLSPATH will be  used  when  the
25       process has root privileges.  If NLSPATH does not exist in the environ‐
26       ment, or if a message catalog cannot be opened  in  any  of  the  paths
27       specified  by  it,  then  an implementation defined path is used.  This
28       latter default path may depend on the LC_MESSAGES locale  setting  when
29       the flag argument is NL_CAT_LOCALE and on the LANG environment variable
30       when the flag argument is 0.  Changing the LC_MESSAGES part of the  lo‐
31       cale may invalidate open catalog descriptors.
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33       The  flag  argument to catopen() is used to indicate the source for the
34       language to use.  If it is set to NL_CAT_LOCALE, then it will  use  the
35       current  locale  setting  for  LC_MESSAGES.  Otherwise, it will use the
36       LANG environment variable.
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38       The function catclose() closes the message catalog identified by  cata‐
39       log.   It  invalidates any subsequent references to the message catalog
40       defined by catalog.
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RETURN VALUE

43       The function catopen() returns a message  catalog  descriptor  of  type
44       nl_catd on success.  On failure, it returns (nl_catd) -1 and sets errno
45       to indicate the error.  The possible error values include all  possible
46       values for the open(2) call.
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48       The function catclose() returns 0 on success, or -1 on failure.
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ENVIRONMENT

51       LC_MESSAGES
52              May  be  the  source of the LC_MESSAGES locale setting, and thus
53              determine the language to use if flag is set to NL_CAT_LOCALE.
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55       LANG   The language to use if flag is 0.
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ATTRIBUTES

58       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
59       tributes(7).
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61       ┌────────────────────────────────────────┬───────────────┬─────────────┐
62       │Interface                               │ Attribute     │ Value       │
63       ├────────────────────────────────────────┼───────────────┼─────────────┤
64       │catopen()                               │ Thread safety │ MT-Safe env │
65       ├────────────────────────────────────────┼───────────────┼─────────────┤
66       │catclose()                              │ Thread safety │ MT-Safe     │
67       └────────────────────────────────────────┴───────────────┴─────────────┘
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CONFORMING TO

70       POSIX.1-2001, POSIX.1-2008.
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NOTES

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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COLOPHON

81       This  page  is  part of release 5.13 of the Linux man-pages project.  A
82       description of the project, information about reporting bugs,  and  the
83       latest     version     of     this    page,    can    be    found    at
84       https://www.kernel.org/doc/man-pages/.
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88GNU                               2021-03-22                        CATOPEN(3)