collapseos/tools/blkunpack.c
2020-12-21 17:02:36 -05:00

69 lines
1.7 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
/* Unpacks blkfs into its source form.
*
* If numerical "upto" is specified, we stop unpacking when reaching this
* blkno.
*/
void usage()
{
fprintf(stderr, "Usage: blkunpack [upto] < blkfs > blk.fs\n");
}
int main(int argc, char *argv[])
{
char buf[1024];
int blkid = 0;
int upto = 0;
if (argc > 2) {
usage();
return 1;
}
if (argc == 2) {
upto = strtol(argv[1], NULL, 10);
}
while (fread(buf, 1024, 1, stdin) == 1) {
int linecnt = 0 ;
for (int i=1023; i>=0; i--) {
if (buf[i]) {
linecnt = (i / 64) + 1;
break;
}
}
if (linecnt) {
// not an empty block
printf("( ----- %03d )\n", blkid);
for (int i=0; i<linecnt; i++) {
char *line = &buf[i*64];
// line length is *not* strlen()! it's the
// position of the first non-null, starting
// from the right. Then, we normalize nulls
// to space.
int j;
for (j=63; j>=0; j--) {
if (line[j] != '\0') {
break;
}
}
int len = j+1;
if (len) {
for (; j>=0; j--) {
if (line[j] == '\0') {
line[j] = ' ';
}
}
fwrite(line, len, 1, stdout);
}
fputc('\n', stdout);
}
}
blkid++;
if (blkid == upto) {
break;
}
}
return 0;
}