icuSources/tools/toolutil/ucbuf.c

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 1998-2006, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 *******************************************************************************
   8 *
   9 * File ucbuf.c
  10 *
  11 * Modification History:
  12 *
  13 *   Date        Name        Description
  14 *   05/10/01    Ram         Creation.
  15 *******************************************************************************
  16 */
  17
  18 #include "unicode/utypes.h"
  19 #include "unicode/putil.h"
  20 #include "unicode/ucnv.h"
  21 #include "unicode/ucnv_err.h"
  22 #include "filestrm.h"
  23 #include "cstring.h"
  24 #include "cmemory.h"
  25 #include "ustrfmt.h"
  26 #include "unicode/ustring.h"
  27 #include "unicode/uchar.h"
  28 #include "ucbuf.h"
  29 #include <stdio.h>
  30
  31 #if !UCONFIG_NO_CONVERSION
  32
  33
  34 #define MAX_IN_BUF 1000
  35 #define MAX_U_BUF 1500
  36 #define CONTEXT_LEN 15
  37
  38 struct UCHARBUF {
  39     UChar* buffer;
  40     UChar* currentPos;
  41     UChar* bufLimit;
  42     int32_t bufCapacity;
  43     int32_t remaining;
  44     int32_t signatureLength;
  45     FileStream* in;
  46     UConverter* conv;
  47     UBool showWarning; /* makes this API not produce any errors */
  48     UBool isBuffered;
  49 };
  50
  51 U_CAPI UBool U_EXPORT2
  52 ucbuf_autodetect_fs(FileStream* in, const char** cp, UConverter** conv, int32_t* signatureLength, UErrorCode* error){
  53     char start[8];
  54     int32_t numRead;
  55
  56     UChar target[1]={ 0 };
  57     UChar* pTarget;
  58     const char* pStart;
  59
  60     /* read a few bytes */
  61     numRead=T_FileStream_read(in, start, sizeof(start));
  62
  63     *cp = ucnv_detectUnicodeSignature(start, numRead, signatureLength, error);
  64
  65     /* unread the bytes beyond what was consumed for U+FEFF */
  66     T_FileStream_rewind(in);
  67     if (*signatureLength > 0) {
  68         numRead = T_FileStream_read(in, start, *signatureLength);
  69     }
  70
  71     if(*cp==NULL){
  72         *conv =NULL;
  73         return FALSE;
  74     }
  75
  76     /* open the converter for the detected Unicode charset */
  77     *conv = ucnv_open(*cp,error);
  78
  79     /* convert and ignore initial U+FEFF, and the buffer overflow */
  80     pTarget = target;
  81     pStart = start;
  82     ucnv_toUnicode(*conv, &pTarget, target+1, &pStart, start+*signatureLength, NULL, FALSE, error);
  83     *signatureLength = (int32_t)(pStart - start);
  84     if(*error==U_BUFFER_OVERFLOW_ERROR) {
  85         *error=U_ZERO_ERROR;
  86     }
  87
  88     /* verify that we successfully read exactly U+FEFF */
  89     if(U_SUCCESS(*error) && (pTarget!=(target+1) || target[0]!=0xfeff)) {
  90         *error=U_INTERNAL_PROGRAM_ERROR;
  91     }
  92
  93
  94     return TRUE;
  95 }
  96 static UBool ucbuf_isCPKnown(const char* cp){
  97     if(ucnv_compareNames("UTF-8",cp)==0){
  98         return TRUE;
  99     }
 100     if(ucnv_compareNames("UTF-16BE",cp)==0){
 101         return TRUE;
 102     }
 103     if(ucnv_compareNames("UTF-16LE",cp)==0){
 104         return TRUE;
 105     }
 106     if(ucnv_compareNames("UTF-16",cp)==0){
 107         return TRUE;
 108     }
 109     if(ucnv_compareNames("UTF-32",cp)==0){
 110         return TRUE;
 111     }
 112     if(ucnv_compareNames("UTF-32BE",cp)==0){
 113         return TRUE;
 114     }
 115     if(ucnv_compareNames("UTF-32LE",cp)==0){
 116         return TRUE;
 117     }
 118     if(ucnv_compareNames("SCSU",cp)==0){
 119         return TRUE;
 120     }
 121     if(ucnv_compareNames("BOCU-1",cp)==0){
 122         return TRUE;
 123     }
 124     if(ucnv_compareNames("UTF-7",cp)==0){
 125         return TRUE;
 126     }
 127     return FALSE;
 128 }
 129
 130 U_CAPI FileStream * U_EXPORT2
 131 ucbuf_autodetect(const char* fileName, const char** cp,UConverter** conv, int32_t* signatureLength,UErrorCode* error){
 132     FileStream* in=NULL;
 133     if(error==NULL || U_FAILURE(*error)){
 134         return NULL;
 135     }
 136     if(conv==NULL || cp==NULL || fileName==NULL){
 137         *error = U_ILLEGAL_ARGUMENT_ERROR;
 138         return NULL;
 139     }
 140     /* open the file */
 141     in= T_FileStream_open(fileName,"rb");
 142
 143     if(in == NULL){
 144         *error=U_FILE_ACCESS_ERROR;
 145         return NULL;
 146     }
 147
 148     if(ucbuf_autodetect_fs(in,cp,conv,signatureLength,error)) {
 149         return in;
 150     } else {
 151         ucnv_close(*conv);
 152         *conv=NULL;
 153         T_FileStream_close(in);
 154         return NULL;
 155     }
 156 }
 157
 158 /* fill the uchar buffer */
 159 static UCHARBUF*
 160 ucbuf_fillucbuf( UCHARBUF* buf,UErrorCode* error){
 161     UChar* pTarget=NULL;
 162     UChar* target=NULL;
 163     const char* source=NULL;
 164     char  carr[MAX_IN_BUF] = {'\0'};
 165     char* cbuf =  carr;
 166     int32_t inputRead=0;
 167     int32_t outputWritten=0;
 168     int32_t offset=0;
 169     const char* sourceLimit =NULL;
 170     int32_t cbufSize=0;
 171     pTarget = buf->buffer;
 172     /* check if we arrived here without exhausting the buffer*/
 173     if(buf->currentPos<buf->bufLimit){
 174         offset = (int32_t)(buf->bufLimit-buf->currentPos);
 175         memmove(buf->buffer,buf->currentPos,offset* sizeof(UChar));
 176     }
 177
 178 #if DEBUG
 179     memset(pTarget+offset,0xff,sizeof(UChar)*(MAX_IN_BUF-offset));
 180 #endif
 181     if(buf->isBuffered){
 182         cbufSize = MAX_IN_BUF;
 183         /* read the file */
 184         inputRead=T_FileStream_read(buf->in,cbuf,cbufSize-offset);
 185         buf->remaining-=inputRead;
 186
 187     }else{
 188         cbufSize = T_FileStream_size(buf->in);
 189         cbuf = (char*)uprv_malloc(cbufSize);
 190         inputRead= T_FileStream_read(buf->in,cbuf,cbufSize);
 191         buf->remaining-=inputRead;
 192     }
 193
 194     /* just to be sure...*/
 195     if ( 0 == inputRead )
 196        buf->remaining = 0;
 197
 198     target=pTarget;
 199     /* convert the bytes */
 200     if(buf->conv){
 201         /* set the callback to stop */
 202         UConverterToUCallback toUOldAction ;
 203         void* toUOldContext;
 204         void* toUNewContext=NULL;
 205         ucnv_setToUCallBack(buf->conv,
 206            UCNV_TO_U_CALLBACK_STOP,
 207            toUNewContext,
 208            &toUOldAction,
 209            (const void**)&toUOldContext,
 210            error);
 211         /* since state is saved in the converter we add offset to source*/
 212         target = pTarget+offset;
 213         source = cbuf;
 214         sourceLimit = source + inputRead;
 215         ucnv_toUnicode(buf->conv,&target,target+(buf->bufCapacity-offset),
 216                         &source,sourceLimit,NULL,
 217                         (UBool)(buf->remaining==0),error);
 218
 219         if(U_FAILURE(*error)){
 220             char context[CONTEXT_LEN];
 221             char preContext[CONTEXT_LEN];
 222             char postContext[CONTEXT_LEN];
 223             int8_t len = CONTEXT_LEN;
 224             int32_t start=0;
 225             int32_t stop =0;
 226             int32_t pos =0;
 227             /* use erro1 to preserve the error code */
 228             UErrorCode error1 =U_ZERO_ERROR;
 229
 230             if( buf->showWarning==TRUE){
 231                 fprintf(stderr,"\n###WARNING: Encountered abnormal bytes while"
 232                                " converting input stream to target encoding: %s\n",
 233                                u_errorName(*error));
 234             }
 235
 236
 237             /* now get the context chars */
 238             ucnv_getInvalidChars(buf->conv,context,&len,&error1);
 239             context[len]= 0 ; /* null terminate the buffer */
 240
 241             pos = (int32_t)(source - cbuf - len);
 242
 243             /* for pre-context */
 244             start = (pos <=CONTEXT_LEN)? 0 : (pos - (CONTEXT_LEN-1));
 245             stop  = pos-len;
 246
 247             memcpy(preContext,cbuf+start,stop-start);
 248             /* null terminate the buffer */
 249             preContext[stop-start] = 0;
 250
 251             /* for post-context */
 252             start = pos+len;
 253             stop  = (int32_t)(((pos+CONTEXT_LEN)<= (sourceLimit-cbuf) )? (pos+(CONTEXT_LEN-1)) : (sourceLimit-cbuf));
 254
 255             memcpy(postContext,source,stop-start);
 256             /* null terminate the buffer */
 257             postContext[stop-start] = 0;
 258
 259             if(buf->showWarning ==TRUE){
 260                 /* print out the context */
 261                 fprintf(stderr,"\tPre-context: %s\n",preContext);
 262                 fprintf(stderr,"\tContext: %s\n",context);
 263                 fprintf(stderr,"\tPost-context: %s\n", postContext);
 264             }
 265
 266             /* reset the converter */
 267             ucnv_reset(buf->conv);
 268
 269             /* set the call back to substitute
 270              * and restart conversion
 271              */
 272             ucnv_setToUCallBack(buf->conv,
 273                UCNV_TO_U_CALLBACK_SUBSTITUTE,
 274                toUNewContext,
 275                &toUOldAction,
 276                (const void**)&toUOldContext,
 277                &error1);
 278
 279             /* reset source and target start positions */
 280             target = pTarget+offset;
 281             source = cbuf;
 282
 283             /* re convert */
 284             ucnv_toUnicode(buf->conv,&target,target+(buf->bufCapacity-offset),
 285                             &source,sourceLimit,NULL,
 286                             (UBool)(buf->remaining==0),&error1);
 287
 288         }
 289         outputWritten = (int32_t)(target - pTarget);
 290
 291
 292 #if DEBUG
 293         {
 294             int i;
 295             target = pTarget;
 296             for(i=0;i<numRead;i++){
 297               /*  printf("%c", (char)(*target++));*/
 298             }
 299         }
 300 #endif
 301
 302     }else{
 303         u_charsToUChars(cbuf,target+offset,inputRead);
 304         outputWritten=((buf->remaining>cbufSize)? cbufSize:inputRead+offset);
 305     }
 306     buf->currentPos = pTarget;
 307     buf->bufLimit=pTarget+outputWritten;
 308     *buf->bufLimit=0; /*NUL terminate*/
 309     if(cbuf!=carr){
 310         uprv_free(cbuf);
 311     }
 312     return buf;
 313 }
 314
 315
 316
 317 /* get a UChar from the stream*/
 318 U_CAPI int32_t U_EXPORT2
 319 ucbuf_getc(UCHARBUF* buf,UErrorCode* error){
 320     if(error==NULL || U_FAILURE(*error)){
 321         return FALSE;
 322     }
 323     if(buf->currentPos>=buf->bufLimit){
 324         if(buf->remaining==0){
 325             return U_EOF;
 326         }
 327         buf=ucbuf_fillucbuf(buf,error);
 328         if(U_FAILURE(*error)){
 329             return U_EOF;
 330         }
 331     }
 332
 333     return *(buf->currentPos++);
 334 }
 335
 336 /* get a UChar32 from the stream*/
 337 U_CAPI int32_t U_EXPORT2
 338 ucbuf_getc32(UCHARBUF* buf,UErrorCode* error){
 339     int32_t retVal = (int32_t)U_EOF;
 340     if(error==NULL || U_FAILURE(*error)){
 341         return FALSE;
 342     }
 343     if(buf->currentPos+1>=buf->bufLimit){
 344         if(buf->remaining==0){
 345             return U_EOF;
 346         }
 347         buf=ucbuf_fillucbuf(buf,error);
 348         if(U_FAILURE(*error)){
 349             return U_EOF;
 350         }
 351     }
 352     if(UTF_IS_LEAD(*(buf->currentPos))){
 353         retVal=UTF16_GET_PAIR_VALUE(*(buf->currentPos++),*(buf->currentPos++));
 354     }else{
 355         retVal = *(buf->currentPos++);
 356     }
 357     return retVal;
 358 }
 359
 360 /* u_unescapeAt() callback to return a UChar*/
 361 static UChar U_CALLCONV
 362 _charAt(int32_t offset, void *context) {
 363     return ((UCHARBUF*) context)->currentPos[offset];
 364 }
 365
 366 /* getc and escape it */
 367 U_CAPI int32_t U_EXPORT2
 368 ucbuf_getcx32(UCHARBUF* buf,UErrorCode* error) {
 369     int32_t length;
 370     int32_t offset;
 371     UChar32 c32,c1,c2;
 372     if(error==NULL || U_FAILURE(*error)){
 373         return FALSE;
 374     }
 375     /* Fill the buffer if it is empty */
 376     if (buf->currentPos >=buf->bufLimit-2) {
 377         ucbuf_fillucbuf(buf,error);
 378     }
 379
 380     /* Get the next character in the buffer */
 381     if (buf->currentPos < buf->bufLimit) {
 382         c1 = *(buf->currentPos)++;
 383     } else {
 384         c1 = U_EOF;
 385     }
 386
 387     c2 = *(buf->currentPos);
 388
 389     /* If it isn't a backslash, return it */
 390     if (c1 != 0x005C) {
 391         return c1;
 392     }
 393
 394     /* Determine the amount of data in the buffer */
 395     length = (int32_t)(buf->bufLimit - buf->currentPos);
 396
 397     /* The longest escape sequence is \Uhhhhhhhh; make sure
 398        we have at least that many characters */
 399     if (length < 10) {
 400
 401         /* fill the buffer */
 402         ucbuf_fillucbuf(buf,error);
 403         length = (int32_t)(buf->bufLimit - buf->buffer);
 404     }
 405
 406     /* Process the escape */
 407     offset = 0;
 408     c32 = u_unescapeAt(_charAt, &offset, length, (void*)buf);
 409
 410     /* check if u_unescapeAt unescaped and converted
 411      * to c32 or not
 412      */
 413     if(c32==0xFFFFFFFF){
 414         if(buf->showWarning) {
 415             char context[20];
 416             int32_t len = 20;
 417             if(length  < len) {
 418                 len = length;
 419             }
 420             context[len]= 0 ; /* null terminate the buffer */
 421             u_UCharsToChars( buf->currentPos, context, len);
 422             fprintf(stderr,"Bad escape: [%c%s]...\n", (int)c1, context);
 423         }
 424         *error= U_ILLEGAL_ESCAPE_SEQUENCE;
 425         return c1;
 426     }else if(c32!=c2 || (c32==0x0075 && c2==0x0075 && c1==0x005C) /* for \u0075 c2=0x0075 and c32==0x0075*/){
 427         /* Update the current buffer position */
 428         buf->currentPos += offset;
 429     }else{
 430         /* unescaping failed so we just return
 431          * c1 and not consume the buffer
 432          * this is useful for rules with escapes
 433          * in resouce bundles
 434          * eg: \' \\ \"
 435          */
 436         return c1;
 437     }
 438
 439     return c32;
 440 }
 441
 442 U_CAPI UCHARBUF* U_EXPORT2
 443 ucbuf_open(const char* fileName,const char** cp,UBool showWarning, UBool buffered, UErrorCode* error){
 444
 445     FileStream* in = NULL;
 446     int32_t fileSize=0;
 447     const char* knownCp;
 448     if(error==NULL || U_FAILURE(*error)){
 449         return NULL;
 450     }
 451     if(cp==NULL || fileName==NULL){
 452         *error = U_ILLEGAL_ARGUMENT_ERROR;
 453         return FALSE;
 454     }
 455     if (!uprv_strcmp(fileName, "-")) {
 456         in = T_FileStream_stdin();
 457     }else{
 458         in = T_FileStream_open(fileName, "rb");
 459     }
 460
 461     if(in!=NULL){
 462         UCHARBUF* buf =(UCHARBUF*) uprv_malloc(sizeof(UCHARBUF));
 463         fileSize = T_FileStream_size(in);
 464         if(buf == NULL){
 465             *error = U_MEMORY_ALLOCATION_ERROR;
 466             T_FileStream_close(in);
 467             return NULL;
 468         }
 469         buf->in=in;
 470         buf->conv=NULL;
 471         buf->showWarning = showWarning;
 472         buf->isBuffered = buffered;
 473         buf->signatureLength=0;
 474         if(*cp==NULL || **cp=='\0'){
 475             /* don't have code page name... try to autodetect */
 476             ucbuf_autodetect_fs(in,cp,&buf->conv,&buf->signatureLength,error);
 477         }else if(ucbuf_isCPKnown(*cp)){
 478             /* discard BOM */
 479             ucbuf_autodetect_fs(in,&knownCp,&buf->conv,&buf->signatureLength,error);
 480         }
 481         if(U_SUCCESS(*error) && buf->conv==NULL) {
 482             buf->conv=ucnv_open(*cp,error);
 483         }
 484         if(U_FAILURE(*error)){
 485             ucnv_close(buf->conv);
 486             uprv_free(buf);
 487             T_FileStream_close(in);
 488             return NULL;
 489         }
 490
 491         if((buf->conv==NULL) && (buf->showWarning==TRUE)){
 492             fprintf(stderr,"###WARNING: No converter defined. Using codepage of system.\n");
 493         }
 494         buf->remaining=fileSize-buf->signatureLength;
 495         if(buf->isBuffered){
 496             buf->bufCapacity=MAX_U_BUF;
 497         }else{
 498             buf->bufCapacity=buf->remaining+buf->signatureLength+1/*for terminating nul*/;
 499         }
 500         buf->buffer=(UChar*) uprv_malloc(U_SIZEOF_UCHAR * buf->bufCapacity );
 501         if (buf->buffer == NULL) {
 502             *error = U_MEMORY_ALLOCATION_ERROR;
 503             ucnv_close(buf->conv);
 504             uprv_free(buf);
 505             T_FileStream_close(in);
 506             return NULL;
 507         }
 508         buf->currentPos=buf->buffer;
 509         buf->bufLimit=buf->buffer;
 510         if(U_FAILURE(*error)){
 511             fprintf(stderr, "Could not open codepage [%s]: %s\n", *cp, u_errorName(*error));
 512             ucnv_close(buf->conv);
 513             uprv_free(buf);
 514             T_FileStream_close(in);
 515             return NULL;
 516         }
 517         buf=ucbuf_fillucbuf(buf,error);
 518         return buf;
 519     }
 520     *error =U_FILE_ACCESS_ERROR;
 521     return NULL;
 522 }
 523
 524
 525
 526 /* TODO: this method will fail if at the
 527  * begining of buffer and the uchar to unget
 528  * is from the previous buffer. Need to implement
 529  * system to take care of that situation.
 530  */
 531 U_CAPI void U_EXPORT2
 532 ucbuf_ungetc(int32_t c,UCHARBUF* buf){
 533     /* decrement currentPos pointer
 534      * if not at the begining of buffer
 535      */
 536     UChar escaped[8] ={'\0'};
 537     int32_t len =0;
 538     if(c > 0xFFFF){
 539         len = uprv_itou(escaped,8,c,16,8);
 540     }else{
 541         len=uprv_itou(escaped,8,c,16,4);
 542     }
 543     if(buf->currentPos!=buf->buffer){
 544         if(*(buf->currentPos-1)==c){
 545             buf->currentPos--;
 546         }else if(u_strncmp(buf->currentPos-len,escaped,len) == 0){
 547             while(--len>0){
 548                 buf->currentPos--;
 549             }
 550         }
 551     }
 552 }
 553
 554 /* frees the resources of UChar* buffer */
 555 static void
 556 ucbuf_closebuf(UCHARBUF* buf){
 557     uprv_free(buf->buffer);
 558     buf->buffer = NULL;
 559 }
 560
 561 /* close the buf and release resources*/
 562 U_CAPI void U_EXPORT2
 563 ucbuf_close(UCHARBUF* buf){
 564     if(buf!=NULL){
 565         if(buf->conv){
 566             ucnv_close(buf->conv);
 567         }
 568         T_FileStream_close(buf->in);
 569         ucbuf_closebuf(buf);
 570         uprv_free(buf);
 571     }
 572 }
 573
 574 /* rewind the buf and file stream */
 575 U_CAPI void U_EXPORT2
 576 ucbuf_rewind(UCHARBUF* buf,UErrorCode* error){
 577     if(error==NULL || U_FAILURE(*error)){
 578         return;
 579     }
 580     if(buf){
 581         buf->currentPos=buf->buffer;
 582         buf->bufLimit=buf->buffer;
 583         T_FileStream_rewind(buf->in);
 584         buf->remaining=T_FileStream_size(buf->in)-buf->signatureLength;
 585
 586         ucnv_resetToUnicode(buf->conv);
 587         if(buf->signatureLength>0) {
 588             UChar target[1]={ 0 };
 589             UChar* pTarget;
 590             char start[8];
 591             const char* pStart;
 592             int32_t numRead;
 593
 594             /* read the signature bytes */
 595             numRead=T_FileStream_read(buf->in, start, buf->signatureLength);
 596
 597             /* convert and ignore initial U+FEFF, and the buffer overflow */
 598             pTarget = target;
 599             pStart = start;
 600             ucnv_toUnicode(buf->conv, &pTarget, target+1, &pStart, start+numRead, NULL, FALSE, error);
 601             if(*error==U_BUFFER_OVERFLOW_ERROR) {
 602                 *error=U_ZERO_ERROR;
 603             }
 604
 605             /* verify that we successfully read exactly U+FEFF */
 606             if(U_SUCCESS(*error) && (numRead!=buf->signatureLength || pTarget!=(target+1) || target[0]!=0xfeff)) {
 607                 *error=U_INTERNAL_PROGRAM_ERROR;
 608             }
 609         }
 610     }
 611 }
 612
 613
 614 U_CAPI int32_t U_EXPORT2
 615 ucbuf_size(UCHARBUF* buf){
 616     if(buf){
 617         if(buf->isBuffered){
 618             return (T_FileStream_size(buf->in)-buf->signatureLength)/ucnv_getMinCharSize(buf->conv);
 619         }else{
 620             return (int32_t)(buf->bufLimit - buf->buffer);
 621         }
 622     }
 623     return 0;
 624 }
 625
 626 U_CAPI const UChar* U_EXPORT2
 627 ucbuf_getBuffer(UCHARBUF* buf,int32_t* len,UErrorCode* error){
 628     if(error==NULL || U_FAILURE(*error)){
 629         return NULL;
 630     }
 631     if(buf==NULL || len==NULL){
 632         *error = U_ILLEGAL_ARGUMENT_ERROR;
 633         return NULL;
 634     }
 635     *len = (int32_t)(buf->bufLimit - buf->buffer);
 636     return buf->buffer;
 637 }
 638
 639 U_CAPI const char* U_EXPORT2
 640 ucbuf_resolveFileName(const char* inputDir, const char* fileName, char* target, int32_t* len, UErrorCode* status){
 641     int32_t requiredLen = 0;
 642     int32_t dirlen =  0;
 643     int32_t filelen = 0;
 644     if(status==NULL || U_FAILURE(*status)){
 645         return NULL;
 646     }
 647
 648     if(inputDir == NULL || fileName == NULL || len==NULL || (target==NULL && *len>0)){
 649         *status = U_ILLEGAL_ARGUMENT_ERROR;
 650         return NULL;
 651     }
 652
 653
 654     dirlen  = (int32_t)uprv_strlen(inputDir);
 655     filelen = (int32_t)uprv_strlen(fileName);
 656     if(inputDir[dirlen-1] != U_FILE_SEP_CHAR) {
 657         requiredLen = dirlen + filelen + 2;
 658         if((*len < requiredLen) || target==NULL){
 659             *len = requiredLen;
 660             *status = U_BUFFER_OVERFLOW_ERROR;
 661             return NULL;
 662         }
 663
 664         target[0] = '\0';
 665         /*
 666          * append the input dir to openFileName if the first char in
 667          * filename is not file seperation char and the last char input directory is  not '.'.
 668          * This is to support :
 669          * genrb -s. /home/icu/data
 670          * genrb -s. icu/data
 671          * The user cannot mix notations like
 672          * genrb -s. /icu/data --- the absolute path specified. -s redundant
 673          * user should use
 674          * genrb -s. icu/data  --- start from CWD and look in icu/data dir
 675          */
 676         if( (fileName[0] != U_FILE_SEP_CHAR) && (inputDir[dirlen-1] !='.')){
 677             uprv_strcpy(target, inputDir);
 678             target[dirlen]     = U_FILE_SEP_CHAR;
 679         }
 680         target[dirlen + 1] = '\0';
 681     } else {
 682         requiredLen = dirlen + filelen + 1;
 683         if((*len < requiredLen) || target==NULL){
 684             *len = requiredLen;
 685             *status = U_BUFFER_OVERFLOW_ERROR;
 686             return NULL;
 687         }
 688
 689         uprv_strcpy(target, inputDir);
 690     }
 691
 692     uprv_strcat(target, fileName);
 693     return target;
 694 }
 695 /*
 696  * Unicode TR 13 says any of the below chars is
 697  * a new line char in a readline function in addition
 698  * to CR+LF combination which needs to be
 699  * handled seperately
 700  */
 701 static UBool ucbuf_isCharNewLine(UChar c){
 702     switch(c){
 703     case 0x000A: /* LF  */
 704     case 0x000D: /* CR  */
 705     case 0x000C: /* FF  */
 706     case 0x0085: /* NEL */
 707     case 0x2028: /* LS  */
 708     case 0x2029: /* PS  */
 709         return TRUE;
 710     default:
 711         return FALSE;
 712     }
 713 }
 714
 715 U_CAPI const UChar* U_EXPORT2
 716 ucbuf_readline(UCHARBUF* buf,int32_t* len,UErrorCode* err){
 717     UChar* temp = buf->currentPos;
 718     UChar* savePos =NULL;
 719     UChar c=0x0000;
 720     if(buf->isBuffered){
 721         /* The input is buffered we have to do more
 722         * for returning a pointer U_TRUNCATED_CHAR_FOUND
 723         */
 724         for(;;){
 725             c = *temp++;
 726             if(buf->remaining==0){
 727                 return NULL; /* end of file is reached return NULL */
 728             }
 729             if(temp>=buf->bufLimit && buf->currentPos == buf->buffer){
 730                 *err= U_TRUNCATED_CHAR_FOUND;
 731                 return NULL;
 732             }else{
 733                 ucbuf_fillucbuf(buf,err);
 734                 if(U_FAILURE(*err)){
 735                     return NULL;
 736                 }
 737             }
 738             /*
 739              * Accoding to TR 13 readLine functions must interpret
 740              * CR, CR+LF, LF, NEL, PS, LS or FF as line seperators
 741              */
 742             /* Windows CR LF */
 743             if(c ==0x0d && temp+1<=buf->bufLimit && *(temp+1) == 0x0a ){
 744                 *len = (int32_t)(temp++ - buf->currentPos);
 745                 savePos = buf->currentPos;
 746                 buf->currentPos = temp;
 747                 return savePos;
 748             }
 749             /* else */
 750
 751             if (temp>=buf->bufLimit|| ucbuf_isCharNewLine(c)){  /* Unipad inserts 2028 line separators! */
 752                 *len = (int32_t)(temp - buf->currentPos);
 753                 savePos = buf->currentPos;
 754                 buf->currentPos = temp;
 755                 return savePos;
 756             }
 757         }
 758     }else{
 759     /* we know that all input is read into the internal
 760     * buffer so we can safely return pointers
 761         */
 762         for(;;){
 763             c = *temp++;
 764
 765             if(buf->currentPos==buf->bufLimit){
 766                 return NULL; /* end of file is reached return NULL */
 767             }
 768             /* Windows CR LF */
 769             if(c ==0x0d && temp+1<=buf->bufLimit && *(temp+1) == 0x0a ){
 770                 *len = (int32_t)(temp++ - buf->currentPos);
 771                 savePos = buf->currentPos;
 772                 buf->currentPos = temp;
 773                 return savePos;
 774             }
 775             /* else */
 776             if (temp>=buf->bufLimit|| ucbuf_isCharNewLine(c)) {  /* Unipad inserts 2028 line separators! */
 777                 *len = (int32_t)(temp - buf->currentPos);
 778                 savePos = buf->currentPos;
 779                 buf->currentPos = temp;
 780                 return savePos;
 781             }
 782         }
 783     }
 784     /* not reached */
 785     /* A compiler warning will appear if all paths don't contain a return statement. */
 786 /*    return NULL;*/
 787 }
 788 #endif