1/*
2**********************************************************************
3* Copyright (c) 2003-2004, International Business Machines
4* Corporation and others.  All Rights Reserved.
5**********************************************************************
6* Author: Alan Liu
7* Created: March 19 2003
8* Since: ICU 2.6
9**********************************************************************
10*/
11#ifndef UCAT_H
12#define UCAT_H
13
14#include "unicode/utypes.h"
15#include "unicode/ures.h"
16
17/**
18 * \file
19 * \brief C API: Message Catalog Wrappers
20 *
21 * This C API provides look-alike functions that deliberately resemble
22 * the POSIX catopen, catclose, and catgets functions.  The underlying
23 * implementation is in terms of ICU resource bundles, rather than
24 * POSIX message catalogs.
25 *
26 * The ICU resource bundles obey standard ICU inheritance policies.
27 * To facilitate this, sets and messages are flattened into one tier.
28 * This is done by creating resource bundle keys of the form
29 * <set_num>%<msg_num> where set_num is the set number and msg_num is
30 * the message number, formatted as decimal strings.
31 *
32 * Example:  Consider a message catalog containing two sets:
33 *
34 * Set 1: Message 4  = "Good morning."
35 *        Message 5  = "Good afternoon."
36 *        Message 7  = "Good evening."
37 *        Message 8  = "Good night."
38 * Set 4: Message 14 = "Please "
39 *        Message 19 = "Thank you."
40 *        Message 20 = "Sincerely,"
41 *
42 * The ICU resource bundle source file would, assuming it is named
43 * "greet.txt", would look like this:
44 *
45 * greet
46 * {
47 *     1%4  { "Good morning." }
48 *     1%5  { "Good afternoon." }
49 *     1%7  { "Good evening." }
50 *     1%8  { "Good night." }
51 *
52 *     4%14 { "Please " }
53 *     4%19 { "Thank you." }
54 *     4%20 { "Sincerely," }
55 * }
56 *
57 * The catgets function is commonly used in combination with functions
58 * like printf and strftime.  ICU components like message format can
59 * be used instead, although they use a different format syntax.
60 * There is an ICU package, icuio, that provides some of
61 * the POSIX-style formatting API.
62 */
63
64U_CDECL_BEGIN
65
66/**
67 * An ICU message catalog descriptor, analogous to nl_catd.
68 *
69 * @stable ICU 2.6
70 */
71typedef UResourceBundle* u_nl_catd;
72
73/**
74 * Open and return an ICU message catalog descriptor. The descriptor
75 * may be passed to u_catgets() to retrieve localized strings.
76 *
77 * @param name string containing the full path pointing to the
78 * directory where the resources reside followed by the package name
79 * e.g. "/usr/resource/my_app/resources/guimessages" on a Unix system.
80 * If NULL, ICU default data files will be used.
81 *
82 * Unlike POSIX, environment variables are not interpolated within the
83 * name.
84 *
85 * @param locale the locale for which we want to open the resource. If
86 * NULL, the default ICU locale will be used (see uloc_getDefault). If
87 * strlen(locale) == 0, the root locale will be used.
88 *
89 * @param ec input/output error code. Upon output,
90 * U_USING_FALLBACK_WARNING indicates that a fallback locale was
91 * used. For example, 'de_CH' was requested, but nothing was found
92 * there, so 'de' was used. U_USING_DEFAULT_WARNING indicates that the
93 * default locale data or root locale data was used; neither the
94 * requested locale nor any of its fallback locales were found.
95 *
96 * @return a message catalog descriptor that may be passed to
97 * u_catgets(). If the ec parameter indicates success, then the caller
98 * is responsible for calling u_catclose() to close the message
99 * catalog. If the ec parameter indicates failure, then NULL will be
100 * returned.
101 *
102 * @stable ICU 2.6
103 */
104U_STABLE u_nl_catd U_EXPORT2
105u_catopen(const char* name, const char* locale, UErrorCode* ec);
106
107/**
108 * Close an ICU message catalog, given its descriptor.
109 *
110 * @param catd a message catalog descriptor to be closed. May be NULL,
111 * in which case no action is taken.
112 *
113 * @stable ICU 2.6
114 */
115U_STABLE void U_EXPORT2
116u_catclose(u_nl_catd catd);
117
118/**
119 * Retrieve a localized string from an ICU message catalog.
120 *
121 * @param catd a message catalog descriptor returned by u_catopen.
122 *
123 * @param set_num the message catalog set number. Sets need not be
124 * numbered consecutively.
125 *
126 * @param msg_num the message catalog message number within the
127 * set. Messages need not be numbered consecutively.
128 *
129 * @param s the default string. This is returned if the string
130 * specified by the set_num and msg_num is not found. It must be
131 * zero-terminated.
132 *
133 * @param len fill-in parameter to receive the length of the result.
134 * May be NULL, in which case it is ignored.
135 *
136 * @param ec input/output error code. May be U_USING_FALLBACK_WARNING
137 * or U_USING_DEFAULT_WARNING. U_MISSING_RESOURCE_ERROR indicates that
138 * the set_num/msg_num tuple does not specify a valid message string
139 * in this catalog.
140 *
141 * @return a pointer to a zero-terminated UChar array which lives in
142 * an internal buffer area, typically a memory mapped/DLL file. The
143 * caller must NOT delete this pointer. If the call is unsuccessful
144 * for any reason, then s is returned.  This includes the situation in
145 * which ec indicates a failing error code upon entry to this
146 * function.
147 *
148 * @stable ICU 2.6
149 */
150U_STABLE const UChar* U_EXPORT2
151u_catgets(u_nl_catd catd, int32_t set_num, int32_t msg_num,
152          const UChar* s,
153          int32_t* len, UErrorCode* ec);
154
155U_CDECL_END
156
157#endif /*UCAT_H*/
158/*eof*/
159