david@dalcs.UUCP (03/16/87)
Index: bin/mt.c 4.3BSD
Description:
mt(1) is documented to recognize the minimal unambiguous
prefix for each of its commands. In fact, it selects the first
matching command in its internal table of commands, and fails
to warn the user that other commands matched.
Repeat-By:
Run the command:
mt fs
and watch the tape spin forward, even though "fs" might have
been intended to mean "fsr".
Fix:
Change mt to search the whole table of commands, and exit if more
than one matches. A diff of the changes follows.
RCS file: RCS/mt.c,v
retrieving revision 1.1
diff -c -r1.1 mt.c
*** /tmp/,RCSt1000487 Mon Mar 16 13:20:52 1987
--- mt.c Mon Mar 16 13:01:17 1987
***************
*** 54,60 ****
{
char line[80], *getenv();
register char *cp;
! register struct commands *comp;
if (argc > 2 && (equal(argv[1], "-t") || equal(argv[1], "-f"))) {
argc -= 2;
--- 54,60 ----
{
char line[80], *getenv();
register char *cp;
! register struct commands *comp, *found = NULL;
if (argc > 2 && (equal(argv[1], "-t") || equal(argv[1], "-f"))) {
argc -= 2;
***************
*** 70,86 ****
cp = argv[1];
for (comp = com; comp->c_name != NULL; comp++)
if (strncmp(cp, comp->c_name, strlen(cp)) == 0)
! break;
! if (comp->c_name == NULL) {
fprintf(stderr, "mt: don't grok \"%s\"\n", cp);
exit(1);
}
! if ((mtfd = open(tape, comp->c_ronly ? 0 : 2)) < 0) {
perror(tape);
exit(1);
}
! if (comp->c_code != MTNOP) {
! mt_com.mt_op = comp->c_code;
mt_com.mt_count = (argc > 2 ? atoi(argv[2]) : 1);
if (mt_com.mt_count < 0) {
fprintf(stderr, "mt: negative repeat count\n");
--- 70,91 ----
cp = argv[1];
for (comp = com; comp->c_name != NULL; comp++)
if (strncmp(cp, comp->c_name, strlen(cp)) == 0)
! if (found == NULL)
! found = comp;
! else {
! fprintf(stderr, "mt: ambiguous command\n");
! exit(1);
! }
! if (found == NULL) {
fprintf(stderr, "mt: don't grok \"%s\"\n", cp);
exit(1);
}
! if ((mtfd = open(tape, found->c_ronly ? 0 : 2)) < 0) {
perror(tape);
exit(1);
}
! if (found->c_code != MTNOP) {
! mt_com.mt_op = found->c_code;
mt_com.mt_count = (argc > 2 ? atoi(argv[2]) : 1);
if (mt_com.mt_count < 0) {
fprintf(stderr, "mt: negative repeat count\n");
***************
*** 87,93 ****
exit(1);
}
if (ioctl(mtfd, MTIOCTOP, &mt_com) < 0) {
! fprintf(stderr, "%s %s %d ", tape, comp->c_name,
mt_com.mt_count);
perror("failed");
exit(2);
--- 92,98 ----
exit(1);
}
if (ioctl(mtfd, MTIOCTOP, &mt_com) < 0) {
! fprintf(stderr, "%s %s %d ", tape, found->c_name,
mt_com.mt_count);
perror("failed");
exit(2);
--
David Trueman
CDN or BITNET: david@cs.dal.cdn UUCP: ...!{seismo|utai}!dalcs!david
ARPA: david%dalcs.uucp@seismo.CSS.GOV CSNET: david%cs.dal.cdn@ubc.csnet