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1 /*
2 *******************************************************************************
3 *
4 *   © 2016 and later: Unicode, Inc. and others.
5 *   License & terms of use: http://www.unicode.org/copyright.html
6 *
7 *******************************************************************************
8 *******************************************************************************
9 *
10 *   Copyright (C) 2000-2014, International Business Machines
11 *   Corporation and others.  All Rights Reserved.
12 *
13 *******************************************************************************
14 *   file name:  ustring.c
15 *   encoding:   UTF-8
16 *   tab size:   8 (not used)
17 *   indentation:4
18 *
19 *   created on: 2000aug15
20 *   created by: Markus W. Scherer
21 *
22 *   This file contains sample code that illustrates the use of Unicode strings
23 *   with ICU.
24 */
25 
26 #define __STDC_FORMAT_MACROS 1
27 #include <inttypes.h>
28 
29 #include <stdio.h>
30 #include "unicode/utypes.h"
31 #include "unicode/uchar.h"
32 #include "unicode/locid.h"
33 #include "unicode/ustring.h"
34 #include "unicode/ucnv.h"
35 #include "unicode/unistr.h"
36 
37 using namespace icu;
38 
39 #ifndef UPRV_LENGTHOF
40 #define UPRV_LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
41 #endif
42 
43 // helper functions -------------------------------------------------------- ***
44 
45 // default converter for the platform encoding
46 static UConverter *cnv=NULL;
47 
48 static void
printUString(const char * announce,const UChar * s,int32_t length)49 printUString(const char *announce, const UChar *s, int32_t length) {
50     static char out[200];
51     UChar32 c;
52     int32_t i;
53     UErrorCode errorCode=U_ZERO_ERROR;
54 
55     /*
56      * Convert to the "platform encoding". See notes in printUnicodeString().
57      * ucnv_fromUChars(), like most ICU APIs understands length==-1
58      * to mean that the string is NUL-terminated.
59      */
60     ucnv_fromUChars(cnv, out, sizeof(out), s, length, &errorCode);
61     if(U_FAILURE(errorCode) || errorCode==U_STRING_NOT_TERMINATED_WARNING) {
62         printf("%sproblem converting string from Unicode: %s\n", announce, u_errorName(errorCode));
63         return;
64     }
65 
66     printf("%s%s {", announce, out);
67 
68     /* output the code points (not code units) */
69     if(length>=0) {
70         /* s is not NUL-terminated */
71         for(i=0; i<length; /* U16_NEXT post-increments */) {
72             U16_NEXT(s, i, length, c);
73             printf(" %04x", c);
74         }
75     } else {
76         /* s is NUL-terminated */
77         for(i=0; /* condition in loop body */; /* U16_NEXT post-increments */) {
78             U16_NEXT(s, i, length, c);
79             if(c==0) {
80                 break;
81             }
82             printf(" %04x", c);
83         }
84     }
85     printf(" }\n");
86 }
87 
88 static void
printUnicodeString(const char * announce,const UnicodeString & s)89 printUnicodeString(const char *announce, const UnicodeString &s) {
90     static char out[200];
91     int32_t i, length;
92 
93     // output the string, converted to the platform encoding
94 
95     // Note for Windows: The "platform encoding" defaults to the "ANSI codepage",
96     // which is different from the "OEM codepage" in the console window.
97     // However, if you pipe the output into a file and look at it with Notepad
98     // or similar, then "ANSI" characters will show correctly.
99     // Production code should be aware of what encoding is required,
100     // and use a UConverter or at least a charset name explicitly.
101     out[s.extract(0, 99, out)]=0;
102     printf("%s%s {", announce, out);
103 
104     // output the code units (not code points)
105     length=s.length();
106     for(i=0; i<length; ++i) {
107         printf(" %04x", s.charAt(i));
108     }
109     printf(" }\n");
110 }
111 
112 // sample code for utf.h macros -------------------------------------------- ***
113 
114 static void
demo_utf_h_macros()115 demo_utf_h_macros() {
116     static UChar input[]={ 0x0061, 0xd800, 0xdc00, 0xdbff, 0xdfff, 0x0062 };
117     UChar32 c;
118     int32_t i;
119     UBool isError;
120 
121     printf("\n* demo_utf_h_macros() -------------- ***\n\n");
122 
123     printUString("iterate forward through: ", input, UPRV_LENGTHOF(input));
124     for(i=0; i<UPRV_LENGTHOF(input); /* U16_NEXT post-increments */) {
125         /* Iterating forwards
126            Codepoint at offset 0: U+0061
127            Codepoint at offset 1: U+10000
128            Codepoint at offset 3: U+10ffff
129            Codepoint at offset 5: U+0062
130         */
131         printf("Codepoint at offset %d: U+", i);
132         U16_NEXT(input, i, UPRV_LENGTHOF(input), c);
133         printf("%04x\n", c);
134     }
135 
136     puts("");
137 
138     isError=false;
139     i=1; /* write position, gets post-incremented so needs to be in an l-value */
140     U16_APPEND(input, i, UPRV_LENGTHOF(input), 0x0062, isError);
141 
142     printUString("iterate backward through: ", input, UPRV_LENGTHOF(input));
143     for(i=UPRV_LENGTHOF(input); i>0; /* U16_PREV pre-decrements */) {
144         U16_PREV(input, 0, i, c);
145         /* Iterating backwards
146            Codepoint at offset 5: U+0062
147            Codepoint at offset 3: U+10ffff
148            Codepoint at offset 2: U+dc00 -- unpaired surrogate because lead surr. overwritten
149            Codepoint at offset 1: U+0062 -- by this BMP code point
150            Codepoint at offset 0: U+0061
151         */
152         printf("Codepoint at offset %d: U+%04x\n", i, c);
153     }
154 }
155 
156 // sample code for Unicode strings in C ------------------------------------ ***
157 
demo_C_Unicode_strings()158 static void demo_C_Unicode_strings() {
159     printf("\n* demo_C_Unicode_strings() --------- ***\n\n");
160 
161     static const UChar text[]={ 0x41, 0x42, 0x43, 0 };          /* "ABC" */
162     static const UChar appendText[]={ 0x61, 0x62, 0x63, 0 };    /* "abc" */
163     static const UChar cmpText[]={ 0x61, 0x53, 0x73, 0x43, 0 }; /* "aSsC" */
164     UChar buffer[32];
165     int32_t compare;
166     int32_t length=u_strlen(text); /* length=3 */
167 
168     /* simple ANSI C-style functions */
169     buffer[0]=0;                    /* empty, NUL-terminated string */
170     u_strncat(buffer, text, 1);     /* append just n=1 character ('A') */
171     u_strcat(buffer, appendText);   /* buffer=="Aabc" */
172     length=u_strlen(buffer);        /* length=4 */
173     printUString("should be \"Aabc\": ", buffer, -1);
174 
175     /* bitwise comparing buffer with text */
176     compare=u_strcmp(buffer, text);
177     if(compare<=0) {
178         printf("String comparison error, expected \"Aabc\" > \"ABC\"\n");
179     }
180 
181     /* Build "A<sharp s>C" in the buffer... */
182     u_strcpy(buffer, text);
183     buffer[1]=0xdf; /* sharp s, case-compares equal to "ss" */
184     printUString("should be \"A<sharp s>C\": ", buffer, -1);
185 
186     /* Compare two strings case-insensitively using full case folding */
187     compare=u_strcasecmp(buffer, cmpText, U_FOLD_CASE_DEFAULT);
188     if(compare!=0) {
189         printf("String case insensitive comparison error, expected \"AbC\" to be equal to \"ABC\"\n");
190     }
191 }
192 
193 // sample code for case mappings with C APIs -------------------------------- ***
194 
demoCaseMapInC()195 static void demoCaseMapInC() {
196     /*
197      * input=
198      *   "aB<capital sigma>"
199      *   "iI<small dotless i><capital dotted I> "
200      *   "<sharp s> <small lig. ffi>"
201      *   "<small final sigma><small sigma><capital sigma>"
202      */
203     static const UChar input[]={
204         0x61, 0x42, 0x3a3,
205         0x69, 0x49, 0x131, 0x130, 0x20,
206         0xdf, 0x20, 0xfb03,
207         0x3c2, 0x3c3, 0x3a3, 0
208     };
209     UChar buffer[32];
210 
211     UErrorCode errorCode;
212     UChar32 c;
213     int32_t i, j, length;
214     UBool isError;
215 
216     printf("\n* demoCaseMapInC() ----------------- ***\n\n");
217 
218     /*
219      * First, use simple case mapping functions which provide
220      * 1:1 code point mappings without context/locale ID.
221      *
222      * Note that some mappings will not be "right" because some "real"
223      * case mappings require context, depend on the locale ID,
224      * and/or result in a change in the number of code points.
225      */
226     printUString("input string: ", input, -1);
227 
228     /* uppercase */
229     isError=false;
230     for(i=j=0; j<UPRV_LENGTHOF(buffer) && !isError; /* U16_NEXT post-increments */) {
231         U16_NEXT(input, i, INT32_MAX, c); /* without length because NUL-terminated */
232         if(c==0) {
233             break; /* stop at terminating NUL, no need to terminate buffer */
234         }
235         c=u_toupper(c);
236         U16_APPEND(buffer, j, UPRV_LENGTHOF(buffer), c, isError);
237     }
238     printUString("simple-uppercased: ", buffer, j);
239     /* lowercase */
240     isError=false;
241     for(i=j=0; j<UPRV_LENGTHOF(buffer) && !isError; /* U16_NEXT post-increments */) {
242         U16_NEXT(input, i, INT32_MAX, c); /* without length because NUL-terminated */
243         if(c==0) {
244             break; /* stop at terminating NUL, no need to terminate buffer */
245         }
246         c=u_tolower(c);
247         U16_APPEND(buffer, j, UPRV_LENGTHOF(buffer), c, isError);
248     }
249     printUString("simple-lowercased: ", buffer, j);
250     /* titlecase */
251     isError=false;
252     for(i=j=0; j<UPRV_LENGTHOF(buffer) && !isError; /* U16_NEXT post-increments */) {
253         U16_NEXT(input, i, INT32_MAX, c); /* without length because NUL-terminated */
254         if(c==0) {
255             break; /* stop at terminating NUL, no need to terminate buffer */
256         }
257         c=u_totitle(c);
258         U16_APPEND(buffer, j, UPRV_LENGTHOF(buffer), c, isError);
259     }
260     printUString("simple-titlecased: ", buffer, j);
261     /* case-fold/default */
262     isError=false;
263     for(i=j=0; j<UPRV_LENGTHOF(buffer) && !isError; /* U16_NEXT post-increments */) {
264         U16_NEXT(input, i, INT32_MAX, c); /* without length because NUL-terminated */
265         if(c==0) {
266             break; /* stop at terminating NUL, no need to terminate buffer */
267         }
268         c=u_foldCase(c, U_FOLD_CASE_DEFAULT);
269         U16_APPEND(buffer, j, UPRV_LENGTHOF(buffer), c, isError);
270     }
271     printUString("simple-case-folded/default: ", buffer, j);
272     /* case-fold/Turkic */
273     isError=false;
274     for(i=j=0; j<UPRV_LENGTHOF(buffer) && !isError; /* U16_NEXT post-increments */) {
275         U16_NEXT(input, i, INT32_MAX, c); /* without length because NUL-terminated */
276         if(c==0) {
277             break; /* stop at terminating NUL, no need to terminate buffer */
278         }
279         c=u_foldCase(c, U_FOLD_CASE_EXCLUDE_SPECIAL_I);
280         U16_APPEND(buffer, j, UPRV_LENGTHOF(buffer), c, isError);
281     }
282     printUString("simple-case-folded/Turkic: ", buffer, j);
283 
284     /*
285      * Second, use full case mapping functions which provide
286      * 1:n code point mappings (n can be 0!) and are sensitive to context and locale ID.
287      *
288      * Note that lower/upper/titlecasing take a locale ID while case-folding
289      * has bit flag options instead, by design of the Unicode SpecialCasing.txt UCD file.
290      *
291      * Also, string titlecasing requires a BreakIterator to find starts of words.
292      * The sample code here passes in a NULL pointer; u_strToTitle() will open and close a default
293      * titlecasing BreakIterator automatically.
294      * For production code where many strings are titlecased it would be more efficient
295      * to open a BreakIterator externally and pass it in.
296      */
297     printUString("\ninput string: ", input, -1);
298 
299     /* lowercase/English */
300     errorCode=U_ZERO_ERROR;
301     length=u_strToLower(buffer, UPRV_LENGTHOF(buffer), input, -1, "en", &errorCode);
302     if(U_SUCCESS(errorCode)) {
303         printUString("full-lowercased/en: ", buffer, length);
304     } else {
305         printf("error in u_strToLower(en)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
306     }
307     /* lowercase/Turkish */
308     errorCode=U_ZERO_ERROR;
309     length=u_strToLower(buffer, UPRV_LENGTHOF(buffer), input, -1, "tr", &errorCode);
310     if(U_SUCCESS(errorCode)) {
311         printUString("full-lowercased/tr: ", buffer, length);
312     } else {
313         printf("error in u_strToLower(tr)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
314     }
315     /* uppercase/English */
316     errorCode=U_ZERO_ERROR;
317     length=u_strToUpper(buffer, UPRV_LENGTHOF(buffer), input, -1, "en", &errorCode);
318     if(U_SUCCESS(errorCode)) {
319         printUString("full-uppercased/en: ", buffer, length);
320     } else {
321         printf("error in u_strToUpper(en)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
322     }
323     /* uppercase/Turkish */
324     errorCode=U_ZERO_ERROR;
325     length=u_strToUpper(buffer, UPRV_LENGTHOF(buffer), input, -1, "tr", &errorCode);
326     if(U_SUCCESS(errorCode)) {
327         printUString("full-uppercased/tr: ", buffer, length);
328     } else {
329         printf("error in u_strToUpper(tr)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
330     }
331     /* titlecase/English */
332     errorCode=U_ZERO_ERROR;
333     length=u_strToTitle(buffer, UPRV_LENGTHOF(buffer), input, -1, NULL, "en", &errorCode);
334     if(U_SUCCESS(errorCode)) {
335         printUString("full-titlecased/en: ", buffer, length);
336     } else {
337         printf("error in u_strToTitle(en)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
338     }
339     /* titlecase/Turkish */
340     errorCode=U_ZERO_ERROR;
341     length=u_strToTitle(buffer, UPRV_LENGTHOF(buffer), input, -1, NULL, "tr", &errorCode);
342     if(U_SUCCESS(errorCode)) {
343         printUString("full-titlecased/tr: ", buffer, length);
344     } else {
345         printf("error in u_strToTitle(tr)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
346     }
347     /* case-fold/default */
348     errorCode=U_ZERO_ERROR;
349     length=u_strFoldCase(buffer, UPRV_LENGTHOF(buffer), input, -1, U_FOLD_CASE_DEFAULT, &errorCode);
350     if(U_SUCCESS(errorCode)) {
351         printUString("full-case-folded/default: ", buffer, length);
352     } else {
353         printf("error in u_strFoldCase(default)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
354     }
355     /* case-fold/Turkic */
356     errorCode=U_ZERO_ERROR;
357     length=u_strFoldCase(buffer, UPRV_LENGTHOF(buffer), input, -1, U_FOLD_CASE_EXCLUDE_SPECIAL_I, &errorCode);
358     if(U_SUCCESS(errorCode)) {
359         printUString("full-case-folded/Turkic: ", buffer, length);
360     } else {
361         printf("error in u_strFoldCase(Turkic)=%" PRId32 " error=%s\n", length, u_errorName(errorCode));
362     }
363 }
364 
365 // sample code for case mappings with C++ APIs ------------------------------ ***
366 
demoCaseMapInCPlusPlus()367 static void demoCaseMapInCPlusPlus() {
368     /*
369      * input=
370      *   "aB<capital sigma>"
371      *   "iI<small dotless i><capital dotted I> "
372      *   "<sharp s> <small lig. ffi>"
373      *   "<small final sigma><small sigma><capital sigma>"
374      */
375     static const UChar input[]={
376         0x61, 0x42, 0x3a3,
377         0x69, 0x49, 0x131, 0x130, 0x20,
378         0xdf, 0x20, 0xfb03,
379         0x3c2, 0x3c3, 0x3a3, 0
380     };
381 
382     printf("\n* demoCaseMapInCPlusPlus() --------- ***\n\n");
383 
384     UnicodeString s(input), t;
385     const Locale &en=Locale::getEnglish();
386     Locale tr("tr");
387 
388     /*
389      * Full case mappings as in demoCaseMapInC(), using UnicodeString functions.
390      * These functions modify the string object itself.
391      * Since we want to keep the input string around, we copy it each time
392      * and case-map the copy.
393      */
394     printUnicodeString("input string: ", s);
395 
396     /* lowercase/English */
397     printUnicodeString("full-lowercased/en: ", (t=s).toLower(en));
398     /* lowercase/Turkish */
399     printUnicodeString("full-lowercased/tr: ", (t=s).toLower(tr));
400     /* uppercase/English */
401     printUnicodeString("full-uppercased/en: ", (t=s).toUpper(en));
402     /* uppercase/Turkish */
403     printUnicodeString("full-uppercased/tr: ", (t=s).toUpper(tr));
404     /* titlecase/English */
405     printUnicodeString("full-titlecased/en: ", (t=s).toTitle(NULL, en));
406     /* titlecase/Turkish */
407     printUnicodeString("full-titlecased/tr: ", (t=s).toTitle(NULL, tr));
408     /* case-folde/default */
409     printUnicodeString("full-case-folded/default: ", (t=s).foldCase(U_FOLD_CASE_DEFAULT));
410     /* case-folde/Turkic */
411     printUnicodeString("full-case-folded/Turkic: ", (t=s).foldCase(U_FOLD_CASE_EXCLUDE_SPECIAL_I));
412 }
413 
414 // sample code for UnicodeString storage models ----------------------------- ***
415 
416 static const UChar readonly[]={
417     0x61, 0x31, 0x20ac
418 };
419 static UChar writeable[]={
420     0x62, 0x32, 0xdbc0, 0xdc01 // includes a surrogate pair for a supplementary code point
421 };
422 static char out[100];
423 
424 static void
demoUnicodeStringStorage()425 demoUnicodeStringStorage() {
426     // These sample code lines illustrate how to use UnicodeString, and the
427     // comments tell what happens internally. There are no APIs to observe
428     // most of this programmatically, except for stepping into the code
429     // with a debugger.
430     // This is by design to hide such details from the user.
431     int32_t i;
432 
433     printf("\n* demoUnicodeStringStorage() ------- ***\n\n");
434 
435     // * UnicodeString with internally stored contents
436     // instantiate a UnicodeString from a single code point
437     // the few (2) UChars will be stored in the object itself
438     UnicodeString one((UChar32)0x24001);
439     // this copies the few UChars into the "two" object
440     UnicodeString two=one;
441     printf("length of short string copy: %d\n", two.length());
442     // set "one" to contain the 3 UChars from readonly
443     // this setTo() variant copies the characters
444     one.setTo(readonly, UPRV_LENGTHOF(readonly));
445 
446     // * UnicodeString with allocated contents
447     // build a longer string that will not fit into the object's buffer
448     one+=UnicodeString(writeable, UPRV_LENGTHOF(writeable));
449     one+=one;
450     one+=one;
451     printf("length of longer string: %d\n", one.length());
452     // copying will use the same allocated buffer and increment the reference
453     // counter
454     two=one;
455     printf("length of longer string copy: %d\n", two.length());
456 
457     // * UnicodeString using readonly-alias to a const UChar array
458     // construct a string that aliases a readonly buffer
459     UnicodeString three(false, readonly, UPRV_LENGTHOF(readonly));
460     printUnicodeString("readonly-alias string: ", three);
461     // copy-on-write: any modification to the string results in
462     // a copy to either the internal buffer or to a newly allocated one
463     three.setCharAt(1, 0x39);
464     printUnicodeString("readonly-aliasing string after modification: ", three);
465     // the aliased array is not modified
466     for(i=0; i<three.length(); ++i) {
467         printf("readonly buffer[%d] after modifying its string: 0x%" PRId32 "\n",
468                i, readonly[i]);
469     }
470     // setTo() readonly alias
471     one.setTo(false, writeable, UPRV_LENGTHOF(writeable));
472     // copying the readonly-alias object with fastCopyFrom() (new in ICU 2.4)
473     // will readonly-alias the same buffer
474     two.fastCopyFrom(one);
475     printUnicodeString("fastCopyFrom(readonly alias of \"writeable\" array): ", two);
476     printf("verify that a fastCopyFrom(readonly alias) uses the same buffer pointer: %d (should be 1)\n",
477         one.getBuffer()==two.getBuffer());
478     // a normal assignment will clone the contents (new in ICU 2.4)
479     two=one;
480     printf("verify that a regular copy of a readonly alias uses a different buffer pointer: %d (should be 0)\n",
481         one.getBuffer()==two.getBuffer());
482 
483     // * UnicodeString using writeable-alias to a non-const UChar array
484     UnicodeString four(writeable, UPRV_LENGTHOF(writeable), UPRV_LENGTHOF(writeable));
485     printUnicodeString("writeable-alias string: ", four);
486     // a modification writes through to the buffer
487     four.setCharAt(1, 0x39);
488     for(i=0; i<four.length(); ++i) {
489         printf("writeable-alias backing buffer[%d]=0x%" PRId32 " "
490                "after modification\n", i, writeable[i]);
491     }
492     // a copy will not alias any more;
493     // instead, it will get a copy of the contents into allocated memory
494     two=four;
495     two.setCharAt(1, 0x21);
496     for(i=0; i<two.length(); ++i) {
497         printf("writeable-alias backing buffer[%d]=0x%" PRId32 " after "
498                "modification of string copy\n", i, writeable[i]);
499     }
500     // setTo() writeable alias, capacity==length
501     one.setTo(writeable, UPRV_LENGTHOF(writeable), UPRV_LENGTHOF(writeable));
502     // grow the string - it will not fit into the backing buffer any more
503     // and will get copied before modification
504     one.append((UChar)0x40);
505     // shrink it back so it would fit
506     one.truncate(one.length()-1);
507     // we still operate on the copy
508     one.setCharAt(1, 0x25);
509     printf("string after growing too much and then shrinking[1]=0x%" PRId32 "\n"
510            "                          backing store for this[1]=0x%" PRId32 "\n",
511            one.charAt(1), writeable[1]);
512     // if we need it in the original buffer, then extract() to it
513     // extract() does not do anything if the string aliases that same buffer
514     // i=min(one.length(), length of array)
515     if(one.length()<UPRV_LENGTHOF(writeable)) {
516         i=one.length();
517     } else {
518         i=UPRV_LENGTHOF(writeable);
519     }
520     one.extract(0, i, writeable);
521     for(i=0; i<UPRV_LENGTHOF(writeable); ++i) {
522         printf("writeable-alias backing buffer[%d]=0x%" PRId32 " after re-extract\n",
523                i, writeable[i]);
524     }
525 }
526 
527 // sample code for UnicodeString instantiations ----------------------------- ***
528 
529 static void
demoUnicodeStringInit()530 demoUnicodeStringInit() {
531     // *** Make sure to read about invariant characters in utypes.h! ***
532     // Initialization of Unicode strings from C literals works _only_ for
533     // invariant characters!
534 
535     printf("\n* demoUnicodeStringInit() ---------- ***\n\n");
536 
537     // the string literal is 32 chars long - this must be counted for the macro
538     UnicodeString invariantOnly=UNICODE_STRING("such characters are safe 123 %-.", 32);
539 
540     /*
541      * In C, we need two macros: one to declare the UChar[] array, and
542      * one to populate it; the second one is a noop on platforms where
543      * wchar_t is compatible with UChar and ASCII-based.
544      * The length of the string literal must be counted for both macros.
545      */
546     /* declare the invString array for the string */
547     U_STRING_DECL(invString, "such characters are safe 123 %-.", 32);
548     /* populate it with the characters */
549     U_STRING_INIT(invString, "such characters are safe 123 %-.", 32);
550 
551     // compare the C and C++ strings
552     printf("C and C++ Unicode strings are equal: %d\n", invariantOnly==UnicodeString(true, invString, 32));
553 
554     /*
555      * convert between char * and UChar * strings that
556      * contain only invariant characters
557      */
558     static const char *cs1="such characters are safe 123 %-.";
559     static UChar us1[40];
560     static char cs2[40];
561     u_charsToUChars(cs1, us1, 33); /* include the terminating NUL */
562     u_UCharsToChars(us1, cs2, 33);
563     printf("char * -> UChar * -> char * with only "
564            "invariant characters: \"%s\"\n",
565            cs2);
566 
567     // initialize a UnicodeString from a string literal that contains
568     // escape sequences written with invariant characters
569     // do not forget to duplicate the backslashes for ICU to see them
570     // then, count each double backslash only once!
571     UnicodeString german=UNICODE_STRING(
572         "Sch\\u00f6nes Auto: \\u20ac 11240.\\fPrivates Zeichen: \\U00102345\\n", 64).
573         unescape();
574     printUnicodeString("german UnicodeString from unescaping:\n    ", german);
575 
576     /*
577      * C: convert and unescape a char * string with only invariant
578      * characters to fill a UChar * string
579      */
580     UChar buffer[200];
581     int32_t length;
582     length=u_unescape(
583         "Sch\\u00f6nes Auto: \\u20ac 11240.\\fPrivates Zeichen: \\U00102345\\n",
584         buffer, UPRV_LENGTHOF(buffer));
585     printf("german C Unicode string from char * unescaping: (length %d)\n    ", length);
586     printUnicodeString("", UnicodeString(buffer));
587 }
588 
589 extern int
main(int argc,const char * argv[])590 main(int argc, const char *argv[]) {
591     UErrorCode errorCode=U_ZERO_ERROR;
592 
593     // Note: Using a global variable for any object is not exactly thread-safe...
594 
595     // You can change this call to e.g. ucnv_open("UTF-8", &errorCode) if you pipe
596     // the output to a file and look at it with a Unicode-capable editor.
597     // This will currently affect only the printUString() function, see the code above.
598     // printUnicodeString() could use this, too, by changing to an extract() overload
599     // that takes a UConverter argument.
600     cnv=ucnv_open(NULL, &errorCode);
601     if(U_FAILURE(errorCode)) {
602         fprintf(stderr, "error %s opening the default converter\n", u_errorName(errorCode));
603         return errorCode;
604     }
605 
606     ucnv_setFromUCallBack(cnv, UCNV_FROM_U_CALLBACK_ESCAPE, UCNV_ESCAPE_C, NULL, NULL, &errorCode);
607     if(U_FAILURE(errorCode)) {
608         fprintf(stderr, "error %s setting the escape callback in the default converter\n", u_errorName(errorCode));
609         ucnv_close(cnv);
610         return errorCode;
611     }
612 
613     demo_utf_h_macros();
614     demo_C_Unicode_strings();
615     demoCaseMapInC();
616     demoCaseMapInCPlusPlus();
617     demoUnicodeStringStorage();
618     demoUnicodeStringInit();
619 
620     ucnv_close(cnv);
621     return 0;
622 }
623