blob: 435e4d09f301e6e5bcefe9c81c8986728aaa3c34
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini getpty implementation for busybox |
4 | * Bjorn Wesen, Axis Communications AB (bjornw@axis.com) |
5 | * |
6 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
7 | */ |
8 | |
9 | #include "libbb.h" |
10 | |
11 | #define DEBUG 0 |
12 | |
13 | int FAST_FUNC xgetpty(char *line) |
14 | { |
15 | int p; |
16 | |
17 | #if ENABLE_FEATURE_DEVPTS |
18 | p = open("/dev/ptmx", O_RDWR); |
19 | if (p > 0) { |
20 | grantpt(p); /* chmod+chown corresponding slave pty */ |
21 | unlockpt(p); /* (what does this do?) */ |
22 | # ifndef HAVE_PTSNAME_R |
23 | { |
24 | const char *name; |
25 | name = ptsname(p); /* find out the name of slave pty */ |
26 | if (!name) { |
27 | bb_perror_msg_and_die("ptsname error (is /dev/pts mounted?)"); |
28 | } |
29 | safe_strncpy(line, name, GETPTY_BUFSIZE); |
30 | } |
31 | # else |
32 | /* find out the name of slave pty */ |
33 | if (ptsname_r(p, line, GETPTY_BUFSIZE-1) != 0) { |
34 | bb_perror_msg_and_die("ptsname error (is /dev/pts mounted?)"); |
35 | } |
36 | line[GETPTY_BUFSIZE-1] = '\0'; |
37 | # endif |
38 | return p; |
39 | } |
40 | #else |
41 | struct stat stb; |
42 | int i; |
43 | int j; |
44 | |
45 | strcpy(line, "/dev/ptyXX"); |
46 | |
47 | for (i = 0; i < 16; i++) { |
48 | line[8] = "pqrstuvwxyzabcde"[i]; |
49 | line[9] = '0'; |
50 | if (stat(line, &stb) < 0) { |
51 | continue; |
52 | } |
53 | for (j = 0; j < 16; j++) { |
54 | line[9] = j < 10 ? j + '0' : j - 10 + 'a'; |
55 | if (DEBUG) |
56 | fprintf(stderr, "Trying to open device: %s\n", line); |
57 | p = open(line, O_RDWR | O_NOCTTY); |
58 | if (p >= 0) { |
59 | line[5] = 't'; |
60 | return p; |
61 | } |
62 | } |
63 | } |
64 | #endif /* FEATURE_DEVPTS */ |
65 | bb_error_msg_and_die("can't find free pty"); |
66 | } |
67 |