disklab.c


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#include <stdio.h>
#include <malloc.h>


extern int fd;

void * getonesec(int sector)
{
        void *data;
        int bytes_read;

        if ( lseek(fd, sector * 512, SEEK_SET) <  0) {/* ... */
                printf("seek file ext2.img error....\n");
                return NULL;
        }
        
        
        data = malloc(512);
       
        if ( (bytes_read = read(fd, data, 512)) < 512 )
                printf("read %d bytes less than 512B...\n", bytes_read);
        
        
        return data;
}


void getlinsec(char *buf, int sector, int sector_cnt)
{
        int bytes_read;

        if ( lseek(fd, sector*512, SEEK_SET) < 0 ) {
                printf("seek file ext2.img error ....\n");
                return;
        }

        if ( (bytes_read = read(fd, buf, 512*sector_cnt)) < 512*sector_cnt) 
                printf("read %d bytes less than %d bytes..\n", 
                       bytes_read, 512 * sector_cnt);
        
}