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/usr/share/doc/libicu-devel/samples/ugrep/

/usr/share/doc/libicu-devel/samples/ugrep

Name	Size	Mode	Actions
Makefile	645	0644	edit dl rm
readme.txt	2873	0644	edit dl rm
ugrep.cpp	14745	0644	edit dl rm
ugrep.sln	1200	0644	edit dl rm
ugrep.vcxproj	10121	0644	edit dl rm
ugrep.vcxproj.filters	880	0644	edit dl rm

Edit: /usr/share/doc/libicu-devel/samples/ugrep/ugrep.cpp (14745B)

/*************************************************************************
*
*   © 2016 and later: Unicode, Inc. and others.
*   License & terms of use: http://www.unicode.org/copyright.html#License
*
**************************************************************************
**************************************************************************
*
*   Copyright (C) 2002-2010, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
***************************************************************************
*/

//
//   ugrep  - an ICU sample program illustrating the use of ICU Regular Expressions.
//
//            The use of the ICU Regex API all occurs within the main()
//            function.  The rest of the code deals with opening files,
//            encoding conversions, printing results, etc.
//
//            This is not a full-featured grep program.  The command line options
//            have been kept to a minimum to avoid complicating the sample code.
//

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "unicode/utypes.h"
#include "unicode/ustring.h"
#include "unicode/regex.h"
#include "unicode/ucnv.h"
#include "unicode/uclean.h"

using namespace icu;

//
//  The following variables contain parameters that may be set from the command line.
//
const char *pattern = NULL;     // The regular expression
int        firstFileNum;        //  argv index of the first file name
UBool      displayFileName = FALSE;
UBool      displayLineNum  = FALSE;

//
//  Info regarding the file currently being processed
//
const char *fileName;      
int         fileLen;              // Length, in UTF-16 Code Units.

UChar      *ucharBuf = 0;         // Buffer, holds converted file.  (Simple minded program, always reads
                                  //   the whole file at once.

char       *charBuf = 0;          // Buffer, for original, unconverted file data.

//
//  Info regarding the line currently being processed
//
int      lineStart;     // Index of first char of the current line in the file buffer
int      lineEnd;       // Index of char following the new line sequence for the current line
int      lineNum;

//
//  Converter, used on output to convert Unicode data back to char *
//             so that it will display in non-Unicode terminal windows.
//
UConverter  *outConverter = 0;

//
//  Function forward declarations
//
void processOptions(int argc, const char **argv);
void nextLine(int start);
void printMatch();
void printUsage();
void readFile(const char *name);

//------------------------------------------------------------------------------------------
//
//   main          for ugrep
//
//           Structurally, all use of the ICU Regular Expression API is in main(),
//           and all of the supporting stuff necessary to make a running program, but
//           not directly related to regular expressions, is factored out into these other
//           functions.
//
//------------------------------------------------------------------------------------------
int main(int argc, const char** argv) {
    UBool     matchFound = FALSE;

//
    //  Process the command line options.
    //
    processOptions(argc, argv);

//
    // Create a RegexPattern object from the user supplied pattern string.
    //
    UErrorCode status = U_ZERO_ERROR;   // All ICU operations report success or failure
                                        //   in a status variable.

UParseError    parseErr;            // In the event of a syntax error in the regex pattern,
                                        //   this struct will contain the position of the
                                        //   error.

RegexPattern  *rePat = RegexPattern::compile(pattern, parseErr, status);
                                        // Note that C++ is doing an automatic conversion
                                        //  of the (char *) pattern to a temporary
                                        //  UnicodeString object.
    if (U_FAILURE(status)) {
        fprintf(stderr, "ugrep:  error in pattern: \"%s\" at position %d\n",
            u_errorName(status), parseErr.offset);
        exit(-1);
    }

//
    // Create a RegexMatcher from the newly created pattern.
    //
    UnicodeString empty;
    RegexMatcher *matcher = rePat->matcher(empty, status);
    if (U_FAILURE(status)) {
        fprintf(stderr, "ugrep:  error in creating RegexMatcher: \"%s\"\n",
            u_errorName(status));
        exit(-1);
    }

//
    // Loop, processing each of the input files.
    //
    for (int fileNum=firstFileNum; fileNum < argc; fileNum++) {
        readFile(argv[fileNum]);

//
        //  Loop through the lines of a file, trying to match the regex pattern on each.
        //
        for (nextLine(0); lineStart<fileLen; nextLine(lineEnd)) {
            UnicodeString s(FALSE, ucharBuf+lineStart, lineEnd-lineStart);
            matcher->reset(s);
            if (matcher->find()) {
                matchFound = TRUE;
                printMatch();
            }
        }
    }

//
    //  Clean up
    //
    delete matcher;
    delete rePat;
    free(ucharBuf);
    free(charBuf);
    ucnv_close(outConverter);
    
    u_cleanup();       // shut down ICU, release any cached data it owns.

return matchFound? 0: 1;
}

//------------------------------------------------------------------------------------------
//
//   doOptions          Run through the command line options, and set
//                      the global variables accordingly.
//
//                      exit without returning if an error occurred and
//                      ugrep should not proceed further.
//
//------------------------------------------------------------------------------------------
void processOptions(int argc, const char **argv) {
    int            optInd;
    UBool          doUsage   = FALSE;
    UBool          doVersion = FALSE;
    const char    *arg;

for(optInd = 1; optInd < argc; ++optInd) {
        arg = argv[optInd];
        
        /* version info */
        if(strcmp(arg, "-V") == 0 || strcmp(arg, "--version") == 0) {
            doVersion = TRUE;
        }
        /* usage info */
        else if(strcmp(arg, "--help") == 0) {
            doUsage = TRUE;
        }
        else if(strcmp(arg, "-n") == 0 || strcmp(arg, "--line-number") == 0) {
            displayLineNum = TRUE;
        }
        /* POSIX.1 says all arguments after -- are not options */
        else if(strcmp(arg, "--") == 0) {
            /* skip the -- */
            ++optInd;
            break;
        }
        /* unrecognized option */
        else if(strncmp(arg, "-", strlen("-")) == 0) {
            printf("ugrep: invalid option -- %s\n", arg+1);
            doUsage = TRUE;
        }
        /* done with options */
        else {
            break;
        }
    }

if (doUsage) {
        printUsage();
        exit(0);
    }

if (doVersion) {
        printf("ugrep version 0.01\n");
        if (optInd == argc) {
            exit(0);
        }
    }

int  remainingArgs = argc-optInd;     // pattern file ...
    if (remainingArgs < 2) {
        fprintf(stderr, "ugrep:  files or pattern are missing.\n");
        printUsage();
        exit(1);
    }

if (remainingArgs > 2) {
        // More than one file to be processed.   Display file names with match output.
        displayFileName = TRUE;
    }

pattern      = argv[optInd];
    firstFileNum = optInd+1;
}

//------------------------------------------------------------------------------------------
//
//   printUsage
//
//------------------------------------------------------------------------------------------
void printUsage() {
    printf("ugrep [options] pattern file...\n"
        "     -V or --version     display version information\n"
        "     --help              display this help and exit\n"
        "     --                  stop further option processing\n"
        "-n,  --line-number       Prefix each line of output with the line number within its input file.\n"
        );
    exit(0);
}

//------------------------------------------------------------------------------------------
//
//    readFile          Read a file into memory, and convert it to Unicode.
//
//                      Since this is just a demo program, take the simple minded approach
//                      of always reading the whole file at once.  No intelligent buffering
//                      is done.
//
//------------------------------------------------------------------------------------------
void readFile(const char *name) {

//
    //  Initialize global file variables
    //
    fileName = name;
    fileLen  = 0;      // zero length prevents processing in case of errors.

//
    //  Open the file and determine its size.
    //
    FILE *file = fopen(name, "rb");
    if (file == 0 ) {
        fprintf(stderr, "ugrep: Could not open file \"%s\"\n", fileName);
        return;
    }
    fseek(file, 0, SEEK_END);
    int rawFileLen = ftell(file);
    fseek(file, 0, SEEK_SET);

//
    //   Read in the file
    //
    charBuf    = (char *)realloc(charBuf, rawFileLen+1);   // Need error checking...
    int t = static_cast<int>(fread(charBuf, 1, rawFileLen, file));
    if (t != rawFileLen)  {
        fprintf(stderr, "Error reading file \"%s\"\n", fileName);
        fclose(file);
        return;
    }
    charBuf[rawFileLen]=0;
    fclose(file);

//
    // Look for a Unicode Signature (BOM) in the data
    //
    int32_t        signatureLength;
    const char *   charDataStart = charBuf;
    UErrorCode     status        = U_ZERO_ERROR;
    const char*    encoding      = ucnv_detectUnicodeSignature(
                           charDataStart, rawFileLen, &signatureLength, &status);
    if (U_FAILURE(status)) {
        fprintf(stderr, "ugrep: ICU Error \"%s\" from ucnv_detectUnicodeSignature()\n",
            u_errorName(status));
        return;
    }
    if(encoding!=NULL ){
        charDataStart  += signatureLength;
        rawFileLen     -= signatureLength;
    }

//
    // Open a converter to take the file to UTF-16
    //
    UConverter* conv;
    conv = ucnv_open(encoding, &status);
    if (U_FAILURE(status)) {
        fprintf(stderr, "ugrep: ICU Error \"%s\" from ucnv_open()\n", u_errorName(status));
        return;
    }

//
    // Convert the file data to UChar.
    //  Preflight first to determine required buffer size.
    //
    uint32_t destCap = ucnv_toUChars(conv,
                       NULL,           //  dest,
                       0,              //  destCapacity,
                       charDataStart,
                       rawFileLen,
                       &status);
    if (status != U_BUFFER_OVERFLOW_ERROR) {
        fprintf(stderr, "ugrep: ucnv_toUChars: ICU Error \"%s\"\n", u_errorName(status));
        return;
    };
    
    status = U_ZERO_ERROR;
    ucharBuf = (UChar *)realloc(ucharBuf, (destCap+1) * sizeof(UChar));
    ucnv_toUChars(conv,
        ucharBuf,           //  dest,
        destCap+1,
        charDataStart,
        rawFileLen,
        &status);
    if (U_FAILURE(status)) {
        fprintf(stderr, "ugrep: ucnv_toUChars: ICU Error \"%s\"\n", u_errorName(status));
        return;
    };
    ucnv_close(conv);
    
    //
    //  Successful conversion.  Set the global size variables so that
    //     the rest of the processing will proceed for this file.
    //
    fileLen = destCap;
}

//------------------------------------------------------------------------------------------
//
//   nextLine           Advance the line index variables, starting at the
//                      specified position in the input file buffer, by
//                      scanning forward until the next end-of-line.
//
//                      Need to take into account all of the possible Unicode
//                      line ending sequences.
//
//------------------------------------------------------------------------------------------
void nextLine(int  startPos) {
    if (startPos == 0) {
        lineNum = 0;
    } else {
        lineNum++;
    }
    lineStart = lineEnd = startPos;

for (;;) {
        if (lineEnd >= fileLen) {
            return;
        }
        UChar c = ucharBuf[lineEnd];
        lineEnd++;
        if (c == 0x0a   ||       // Line Feed
            c == 0x0c   ||       // Form Feed
            c == 0x0d   ||       // Carriage Return
            c == 0x85   ||       // Next Line
            c == 0x2028 ||       // Line Separator
            c == 0x2029)         // Paragraph separator
        { 
            break;
        }
    }

// Check for CR/LF sequence, and advance over the LF if we're in the middle of one.
    if (lineEnd < fileLen           &&
        ucharBuf[lineEnd-1] == 0x0d &&
        ucharBuf[lineEnd]   == 0x0a) 
    {
        lineEnd++;
    }
}

//------------------------------------------------------------------------------------------
//
//   printMatch         Called when a matching line has been located.
//                      Print out the line from the file with the match, after
//                         converting it back to the default code page.
//
//------------------------------------------------------------------------------------------
void printMatch() {
    char                buf[2000];
    UErrorCode         status       = U_ZERO_ERROR;

// If we haven't already created a converter for output, do it now.
    if (outConverter == 0) {
        outConverter = ucnv_open(NULL, &status);
        if (U_FAILURE(status)) {
            fprintf(stderr, "ugrep:  Error opening default converter: \"%s\"\n",
                u_errorName(status));
            exit(-1);
        }
    };

// Convert the line to be printed back to the default 8 bit code page.
    //   If the line is too long for our buffer, just truncate it.
    ucnv_fromUChars(outConverter,
                    buf,                   // destination buffer for conversion
                    sizeof(buf),           // capacity of destination buffer
                    &ucharBuf[lineStart],   // Input to conversion
                    lineEnd-lineStart,     // number of UChars to convert
                    &status);
    buf[sizeof(buf)-1] = 0;                // Add null for use in case of too long lines.
                                           // The converter null-terminates its output unless
                                           //   the buffer completely fills.
   
    if (displayFileName) {
        printf("%s:", fileName);
    }
    if (displayLineNum) {
        printf("%d:", lineNum);
    }
    printf("%s", buf);
}

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