mike@BRL.MIL (Mike Muuss) (12/04/90)
You might find this program helpful in your quest to recover from your failing
disk drive.
Best,
-Mike
----
/*
* E C O P Y . C
*
* Quick program to do large DMAs until an error is found, and then
* do single-sector DMAs to isolate the bad block(s) in question.
* Input is on stdin.
* Data recovered is output on stdout.
* This program has the property that the output will be exactly the
* same length as the input, with a best-effort attempt at the contents
* of the file in cases of error.
*/
#include <stdio.h>
char *malloc();
#ifdef sel
#define SECTLEN 1024
#else
#define SECTLEN 512
#endif
main(argc, argv)
char **argv;
{
register int i,j;
int nsectors;
int size;
long pos;
char *buf;
if( argc < 2 || argc > 3 ) {
fprintf(stderr,"Usage: ecopy sectors/DMA [sectors_offset]\n");
exit(1);
}
nsectors = atoi( argv[1] );
if( nsectors < 1 || nsectors > 1024 ) {
fprintf(stderr,"DMA size %d.*%d. unreasonable\n", nsectors, SECTLEN );
exit(2);
}
size = nsectors * SECTLEN;
if( (buf = malloc( size )) == ((char *)0) ) {
fprintf(stderr,"Unable to malloc specified buffer\n");
exit(3);
}
if( argc == 3 )
pos = atoi( argv[2] ) * SECTLEN;
else
pos = 0L;
fprintf(stderr,"Starting with %d*%d byte DMAs at sector %d\n",
nsectors, SECTLEN, pos/SECTLEN );
for( ; ; pos += size ) {
if( lseek( 0, pos, 0 ) == -1L )
perror("lseek");
if( (i = read( 0, buf, size )) == size ) {
write( 1, buf, size);
continue;
}
fprintf(stderr,"error with starting sector %d, count was %d, s/b %d\n",
pos/SECTLEN, i, size );
if( i == 0 ) exit(0);
for( j = 0; j < nsectors; j++ ) {
if( lseek( 0, pos+(j*SECTLEN), 0 ) == -1L ) {
perror("lseek");
exit(1);
}
if( (i=read(0,buf,SECTLEN)) == SECTLEN ) {
write(1, buf, SECTLEN);
continue;
}
fprintf(stderr,"BAD sector %d, count was %d, s/b %d\n",
(pos/SECTLEN)+j, i, SECTLEN );
if( i == 0 ) exit(0);
if( i < 0 ) i = SECTLEN;
fprintf(stderr,"wrote %d bytes\n", i);
write( 1, buf, i );
}
}
}