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#include <init/types.h>
#include <shared/syscalls.h>
#include <stdint.h>
extern int tty_fd;
static int oct_parse(char *str, size_t len);
int memcmp(const void *s1, const void *s2, size_t n); // TODO move to a dedicated file
void tar_driver(void *base) {
// iterate over all sectors, printing filenames
while (0 == memcmp(base + 257, "ustar", 5)) {
int size = oct_parse(base + 124, 12);
_syscall_write(tty_fd, base, 100);
_syscall_write(tty_fd, " ", 1);
base += 512; // skip metadata sector
base += (size + 511) & ~511; // skip file (size rounded up to 512)
// TODO might pagefault if the last sector was at a page boundary
}
_syscall_write(tty_fd, "done.", 5);
}
static int oct_parse(char *str, size_t len) {
int res = 0;
for (size_t i = 0; i < len; i++) {
res *= 8;
res += str[i] - '0'; // no format checking
}
return res;
}
int memcmp(const void *s1, const void *s2, size_t n) {
const unsigned char *c1 = s1, *c2 = s2;
for (size_t i = 0; i < n; i++) {
if (c1[i] != c2[i]) {
if (c1[i] < c2[i]) return -1;
else return 1;
}
}
return 0;
}
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