databin.c

cygwin, 著名的在win32下模拟unix操作系统的东东

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 * 
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 * 
 * http://www.sgi.com 
 * 
 * For further information regarding this notice, see: 
 * 
 * http://oss.sgi.com/projects/GenInfo/NoticeExplan/
 */
#include <stdio.h>
#include <sys/param.h>
#include <string.h> /* memset */
#include <stdlib.h> /* rand */
#include "databin.h"

#if UNIT_TEST
#include <malloc.h>
#endif

static char Errmsg[80];

void
databingen (mode, buffer, bsize, offset)
int mode;	/* either a, c, r, o, z or C */
unsigned char *buffer;	/* buffer pointer */
int bsize;	/* size of buffer */
int offset;	/* offset into the file where buffer starts */
{
int ind;

        switch (mode)
        {
        default:
        case 'a':	/* alternating bit pattern */
                memset(buffer,0x55,bsize);
                break;

        case 'c':	/* checkerboard pattern */
                memset(buffer,0xf0,bsize);
                break;

	case 'C':	/* */
                for (ind=0;ind< bsize;ind++) {
		    buffer[ind] = ((offset+ind)%8 & 0177);
		}
		break;

	case 'o':
		memset(buffer,0xff,bsize);
		break;

	case 'z':
		memset(buffer,0x0,bsize);
		break;

        case 'r':	/* random */
                for (ind=0;ind< bsize;ind++) {
		    buffer[ind] = (rand () & 0177) | 0100;
		}
        }
}

/***********************************************************************
 *
 * return values:
 *      >= 0 : error at byte offset into the file, offset+buffer[0-(bsize-1)]
 *      < 0  : no error
 ***********************************************************************/
int
databinchk(mode, buffer, bsize, offset, errmsg)
int mode;	/* either a, c, r, z, o, or C */
unsigned char *buffer;	/* buffer pointer */
int bsize;	/* size of buffer */
int offset;	/* offset into the file where buffer starts */
char **errmsg;
{
    int cnt;
    unsigned char *chr;
    int total;
    long expbits;
    long actbits;

	chr=buffer;
	total=bsize;

	if ( errmsg != NULL ) {
	    *errmsg = Errmsg;
	}
	
        switch (mode)
        {
        default:
        case 'a':	/* alternating bit pattern */
		expbits=0x55;
                break;

        case 'c':	/* checkerboard pattern */
		expbits=0xf0;
                break;

	case 'C':	/* counting pattern */
                for (cnt=0;cnt< bsize;cnt++) {
		    expbits = ((offset+cnt)%8 & 0177);

		    if ( buffer[cnt] != expbits ) {
			sprintf(Errmsg,
			    "data mismatch at offset %d, exp:%#lo, act:%#o",
			    offset+cnt, expbits, buffer[cnt]);
			return offset+cnt;
		    }
		}
		sprintf(Errmsg, "all %d bytes match desired pattern", bsize);
		return -1;

	case 'o':
		expbits=0xff;
		break;

	case 'z':
		expbits=0;
		break;

        case 'r':
		return -1;	/* no check can be done for random */
        }

	for (cnt=0; cnt<bsize; chr++, cnt++) {
	    actbits = (long)*chr;

	    if ( actbits != expbits ) {
		sprintf(Errmsg, "data mismatch at offset %d, exp:%#lo, act:%#lo",
		    offset+cnt, expbits, actbits);
		return offset+cnt;
	    }
	}

	sprintf(Errmsg, "all %d bytes match desired pattern", bsize);
	return -1; /* all ok */
}

#if UNIT_TEST

/***********************************************************************
 * main for doing unit testing
 ***********************************************************************/
int
main(ac, ag)
int ac;
char **ag;
{

    int size=1023;
    int offset;
    int number;
    unsigned char *buffer;
    int ret;
    char *errmsg;

    if ((buffer=(unsigned char *)malloc(size)) == NULL ) {
	perror("malloc");
	exit(2);
    }


printf("***** for a ****************************\n");
    databingen('a', buffer, size, 0);
    printf("databingen('a', buffer, %d, 0)\n", size);

    ret=databinchk('a', buffer, size, 0, &errmsg);
    printf("databinchk('a', buffer, %d, 0, &errmsg) returned %d: %s\n",
	size, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    offset=232400;
    ret=databinchk('a', &buffer[1], size-1, offset, &errmsg);
    printf("databinchk('a', &buffer[1], %d, %d, &errmsg) returned %d: %s\n",
	size, offset, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    buffer[15]= 0x0;
    printf("changing char 15 (offset (%d+15) = %d) to 0x0\n", offset, offset+15);
    number=offset+15;

    ret=databinchk('a', &buffer[1], size-1, offset+1, &errmsg);
    printf("databinchk('a', &buffer[1], %d, %d, &errmsg) returned %d: %s\n",
	size-1, offset+1, ret, errmsg);
    if ( ret == number )
	printf("\tPASS return value of %d as expected\n", number);
    else
	printf("\tFAIL return value %d, expected %d\n", ret, number);



printf("***** for c ****************************\n");
    databingen('c', buffer, size, 0);
    printf("databingen('c', buffer, %d, 0)\n", size);

    ret=databinchk('c', buffer, size, 0, &errmsg);
    printf("databinchk('c', buffer, %d, 0, &errmsg) returned %d: %s\n",
	size, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    offset=232400;
    ret=databinchk('c', &buffer[1], size-1, offset, &errmsg);
    printf("databinchk('c', &buffer[1], %d, %d, &errmsg) returned %d: %s\n",
	size, offset, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    buffer[15]= 0x0;
    printf("changing char 15 (offset (%d+15) = %d) to 0x0\n", offset, offset+15);
    number=offset+15;

    ret=databinchk('c', &buffer[1], size-1, offset+1, &errmsg);
    printf("databinchk('c', &buffer[1], %d, %d, &errmsg) returned %d: %s\n",
	size-1, offset+1, ret, errmsg);
    if ( ret == number )
	printf("\tPASS return value of %d as expected\n", number);
    else
	printf("\tFAIL return value %d, expected %d\n", ret, number);

printf("***** for C ****************************\n");

    databingen('C', buffer, size, 0);
    printf("databingen('C', buffer, %d, 0)\n", size);

    ret=databinchk('C', buffer, size, 0, &errmsg);
    printf("databinchk('C', buffer, %d, 0, &errmsg) returned %d: %s\n",
	size, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    offset=18;
    ret=databinchk('C', &buffer[18], size-18, 18, &errmsg);
    printf("databinchk('C', &buffer[18], %d, 18, &errmsg) returned %d: %s\n",
	size-18, ret, errmsg);
    if ( ret == -1 )
	printf("\tPASS return value of -1 as expected\n");
    else
	printf("\tFAIL return value %d, expected -1\n", ret);

    buffer[20]= 0x0;
    buffer[21]= 0x0;
    printf("changing char 20 and 21 to 0x0 (offset %d and %d)\n", 20,
	21);

    ret=databinchk('C', &buffer[18], size-18, 18, &errmsg);
    printf("databinchk('C', &buffer[18], %d, 18, &errmsg) returned %d: %s\n",
	size-18, ret, errmsg);

    if ( ret == 20 || ret == 21 )
	printf("\tPASS return value of %d or %d as expected\n",
	    20, 21);
    else
	printf("\tFAIL return value %d, expected %d or %d\n", ret,
	    20, 21 );

    exit(0);

}

#endif