Power-Programmierung/CD2.mdf/doc/mir/debloc_a.c

Text File | 1992-07-02 | 6KB | 206 lines

/*
 * Usage -  debloc_a  ASCII_blocked_file > unblocked_version
 *
 * DEBLOC_A Remove blocking, insert line feeds in ASCII blocked file.
 *
 * input:   ASCII file with four byte inclusive line lengths at the
 *          beginning of every line, no line feeds at end.
 *
 * output:  Same data with counts out, line feeds/carriage returns in.
 *
 * writeup: MIR TUTORIAL ONE, topic 9
 *
 *  Written:    Douglas Lowry   May 11 92
 *              Copyright (C) 1992 Marpex Inc.
 *
 *    The MIR (Mass Indexing and Retrieval) Tutorials explain detailed
 *    usage and co-ordination of the MIR family of programs to analyze,
 *    prepare and index databases (small through gigabyte size), and
 *    how to build integrated retrieval software around the MIR search
 *    engine.  The fifth of the five MIR tutorial series explains how
 *    to extend indexing capability into leading edge search-related
 *    technologies.  For more information, GO IBMPRO on CompuServe;
 *    MIR files are in the DBMS library.  The same files are on the
 *    Canada Remote Systems BBS.  A diskette copy of the Introduction
 *    is available by mail ($10 US... check, Visa or Mastercard);
 *    diskettes with Introduction, Tutorial ONE software and the
 *    shareware Tutorial ONE text cost $29.  Shareware registration
 *    for a tutorial is also $29.
 *
 *    E-mail...
 *                Compuserve  71431,1337
 *                Internet    doug.lowry%canrem.com
 *                UUCP        canrem!doug.lowry
 *                Others:     [e-mail]
 *
 *    FAX...                  416 963-5677
 *
 *    "Snail mail"...         Douglas Lowry, Ph.D.
 *                            Marpex Inc.
 *                            5334 Yonge Street, #1102
 *                            North York, Ontario
 *                            Canada  M2N 6M2
 *
 *    Related database consultation and preparation services are
 *    available through:
 *              Innotech Inc., 2001 Sheppard Avenue E., Suite #118,
 *              North York, Ontario  Canada   M2J 4Z7
 *              Tel.  [phone]   FAX  [phone]
 *
 *  This program is free software; you may redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  (file 05LICENS) along with this program; if not, write to the
 *  Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
 *  USA.
 */

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

#define     MAX_BYTES   2048
#define     repeat      for(;;)

/*
 * declarations
 */

typedef     enum        _bool
             { FALSE = 0, TRUE = 1 }  Bool;

    void        Usage_(), process();
    int         get_data();
    char        *Cmdname_() {    return( "debloc_a" );  }

    static long int  offset ;

/*
 *  MAIN -
 */

main( argc, argv )
    int argc;
    char    **argv;
{
    char    c10 ;
    FILE    *fp ;

    if( argc != 2 )
        Usage_() ;
    c10 = argv[1][0] ;
    if( c10 == '/' || c10 == '-' || c10 == '?' )
        Usage_() ;
    if (( fp = fopen( argv[ 1 ], "r" )) == NULL )
    {
        fprintf( stderr, "Unable to open file %s\n", argv[ 1 ] );
        Usage_() ;
    }

    process( fp );

    fclose( fp );
    exit( 0 );
}
/*
 *  Usage
 */
    void
Usage_()
{
    fprintf( stderr,
"\nUsage:  %s  ASCII_blocked_file > unblocked_version\n\n\
        Remove blocking, insert line feeds in ASCII blocked file.\n\n\
input:  ASCII file with four byte inclusive line lengths at the\n\
        beginning of every line, no line feeds at end.\n\n",
            Cmdname_() );
    fprintf( stderr,
"output: Same data with counts out, line feeds/carriage returns in.\n\n\
writeup: MIR TUTORIAL ONE, topic 9\n\n" ) ;
    exit( 1 ) ;
}
/*
 *  PROCESS -
 */
    void
process( fp )
    FILE    *fp ;
{
    char    buf[ MAX_BYTES ] ;
    int length;     /* length of current line   */
    int j;

    offset = 0 ;

    while( ( length= get_data( fp, buf )) > -1 )
    {
        for( j= 0; j < length; j++ )
            putchar( buf[ j ] );
        if( putchar( '\n' ) != '\n' )
        {
            fprintf( stderr, "FATAL... Unable to write.\n\n" ) ;
            exit( 1 ) ;
        }
    }
    return;
}

/*
 *  GET_DATA
 */

    int
get_data( fp, buf )
    FILE    *fp;
    char    buf[ MAX_BYTES ] ;
{
    char    lil[5];
    int     length,     /* bytes in current line    */
            i;

    lil[ 4 ] = '\0' ;

/*  ...Read in the line size    */

    for( i = 0 ; i < 4 ; i++ )
    {
        if(( lil[i] = fgetc( fp )) == EOF )
            return( -1 );
        if( !isdigit( lil[i] ))
        {
            fprintf( stderr, "Line size out of sync at byte %ld\n",
                offset ) ;
            exit( 1 ) ;
        }
    }

    length = atoi( lil ) - 4;
    offset += 4;

/*  Now load the data stream    */

    if ( length > MAX_BYTES )
    {
        fprintf( stderr, "Oversize line at byte %ld\n", offset );
        exit( 1 ) ;
    }

    if ( fread( buf, sizeof(char), length, fp ) < length )
    {
        fprintf( stderr,"Failure reading line data starting at byte %ld\n",
            offset );
        exit( 1 ) ;
    }
    offset += length;

    return( length );
}