1CATOPEN(3P) POSIX Programmer's Manual CATOPEN(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 catopen — open a message catalog
13
15 #include <nl_types.h>
16 nl_catd catopen(const char *name, int oflag);
18
20 The catopen() function shall open a message catalog and return a mes‐
21 sage catalog descriptor. The name argument specifies the name of the
22 message catalog to be opened. If name contains a '/', then name speci‐
23 fies a pathname for the message catalog. Otherwise, the environment
24 variable NLSPATH is used with name substituted for the %N conversion
25 specification (see the Base Definitions volume of POSIX.1‐2017, Chapter
26 8, Environment Variables); if NLSPATH exists in the environment when
27 the process starts, then if the process has appropriate privileges, the
28 behavior of catopen() is undefined. If NLSPATH does not exist in the
29 environment, or if a message catalog cannot be found in any of the com‐
30 ponents specified by NLSPATH, then an implementation-defined default
31 path shall be used. This default may be affected by the setting of
32 LC_MESSAGES if the value of oflag is NL_CAT_LOCALE, or the LANG envi‐
33 ronment variable if oflag is 0.
34 A message catalog descriptor shall remain valid in a process until that
36 process closes it, or a successful call to one of the exec functions. A
37 change in the setting of the LC_MESSAGES category may invalidate exist‐
38 ing open catalogs.
39 If a file descriptor is used to implement message catalog descriptors,
41 the FD_CLOEXEC flag shall be set; see <fcntl.h>.
42 If the value of the oflag argument is 0, the LANG environment variable
44 is used to locate the catalog without regard to the LC_MESSAGES cate‐
45 gory. If the oflag argument is NL_CAT_LOCALE, the LC_MESSAGES category
46 is used to locate the message catalog (see the Base Definitions volume
47 of POSIX.1‐2017, Section 8.2, Internationalization Variables).
48
50 Upon successful completion, catopen() shall return a message catalog
51 descriptor for use on subsequent calls to catgets() and catclose().
52 Otherwise, catopen() shall return (nl_catd) -1 and set errno to indi‐
53 cate the error.
54
56 The catopen() function may fail if:
57 EACCES Search permission is denied for the component of the path prefix
59 of the message catalog or read permission is denied for the mes‐
60 sage catalog.
61 EMFILE All file descriptors available to the process are currently
63 open.
64 ENAMETOOLONG
66 The length of a component of a pathname is longer than
67 {NAME_MAX}.
68 ENAMETOOLONG
70 The length of a pathname exceeds {PATH_MAX}, or pathname resolu‐
71 tion of a symbolic link produced an intermediate result with a
72 length that exceeds {PATH_MAX}.
73 ENFILE Too many files are currently open in the system.
75 ENOENT The message catalog does not exist or the name argument points
77 to an empty string.
78 ENOMEM Insufficient storage space is available.
80 ENOTDIR
82 A component of the path prefix of the message catalog names an
83 existing file that is neither a directory nor a symbolic link to
84 a directory, or the pathname of the message catalog contains at
85 least one non-<slash> character and ends with one or more trail‐
86 ing <slash> characters and the last pathname component names an
87 existing file that is neither a directory nor a symbolic link to
88 a directory.
89 The following sections are informative.
91
93 None.
94
96 Some implementations of catopen() use malloc() to allocate space for
97 internal buffer areas. The catopen() function may fail if there is
98 insufficient storage space available to accommodate these buffers.
99 Conforming applications must assume that message catalog descriptors
101 are not valid after a call to one of the exec functions.
102 Application developers should be aware that guidelines for the location
104 of message catalogs have not yet been developed. Therefore they should
105 take care to avoid conflicting with catalogs used by other applications
106 and the standard utilities.
107 To be sure that messages produced by an application running with appro‐
109 priate privileges cannot be used by an attacker setting an unexpected
110 value for NLSPATH in the environment to confuse a system administrator,
111 such applications should use pathnames containing a '/' to get defined
112 behavior when using catopen() to open a message catalog.
113
115 None.
116
118 None.
119
121 catclose(), catgets()
122 The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment
124 Variables, <fcntl.h>, <nl_types.h>,
125
127 Portions of this text are reprinted and reproduced in electronic form
128 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
129 table Operating System Interface (POSIX), The Open Group Base Specifi‐
130 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
131 Electrical and Electronics Engineers, Inc and The Open Group. In the
132 event of any discrepancy between this version and the original IEEE and
133 The Open Group Standard, the original IEEE and The Open Group Standard
134 is the referee document. The original Standard can be obtained online
135 at http://www.opengroup.org/unix/online.html .
136 Any typographical or formatting errors that appear in this page are
138 most likely to have been introduced during the conversion of the source
139 files to man page format. To report such errors, see https://www.ker‐
140 nel.org/doc/man-pages/reporting_bugs.html .
141IEEE/The Open Group 2017 CATOPEN(3P)