diff options
| -rw-r--r-- | toys/posix/ps.c | 68 |
1 files changed, 48 insertions, 20 deletions
diff --git a/toys/posix/ps.c b/toys/posix/ps.c index f3ff39bf..bc3060ca 100644 --- a/toys/posix/ps.c +++ b/toys/posix/ps.c @@ -181,6 +181,32 @@ static int match_process(long long *slot) return 1; } +static void find_tty_name(char *out, int rdev) { + int major = (rdev>>8)&0xfff, minor = ((rdev>>12)&0xfff00)|(rdev&0xff); + FILE *fp = fopen("/proc/tty/drivers", "r"); + + if (fp) { + int tty_major; + + while (fscanf(fp, "%*s %s %d %*s %*s", out, &tty_major) == 2) { + // TODO: we could parse the minor range too. + if (tty_major == major) { + struct stat st; + + sprintf(out + strlen(out), "%d", minor); + if (!stat(out, &st) && S_ISCHR(st.st_mode) && st.st_rdev == rdev) { + fclose(fp); + return; + } + } + } + fclose(fp); + } + + // Really couldn't find it, so just show major:minor. + sprintf(out, "%d:%d", major, minor); +} + // dirtree callback. // toybuf used as: 1024 /proc/$PID/stat, 1024 slot[], 2048 /proc/$PID/cmdline static int do_ps(struct dirtree *new) @@ -315,28 +341,30 @@ static int do_ps(struct dirtree *new) // TTY } else if (i==12) { - - // Can we readlink() our way to a name? - for (i=0; i<3; i++) { - struct stat st; - - sprintf(scratch, "%lld/fd/%i", *slot, i); - fd = dirtree_parentfd(new); - if (!fstatat(fd, scratch, &st, 0) && S_ISCHR(st.st_mode) - && st.st_rdev == slot[4] - && 0<(len = readlinkat(fd, scratch, out, 2047))) - { - out[len] = 0; - if (!strncmp(out, "/dev/", 5)) out += 5; - - break; + int rdev = slot[4]; + + // The common case is no tty, and we call that "?" rather than "0:0". + if (rdev == 0) strcpy(out, "?"); + else { + // Can we readlink() our way to a name? + for (i=0; i<3; i++) { + struct stat st; + + sprintf(scratch, "%lld/fd/%i", *slot, i); + fd = dirtree_parentfd(new); + if (!fstatat(fd, scratch, &st, 0) && S_ISCHR(st.st_mode) + && st.st_rdev == rdev + && 0<(len = readlinkat(fd, scratch, out, 2047))) + { + out[len] = 0; + break; + } } - } - // Couldn't find it, show major:minor - if (i==3) { - i = slot[4]; - sprintf(out, "%d:%d", (i>>8)&0xfff, ((i>>12)&0xfff00)|(i&0xff)); + // Couldn't find it, try all the tty drivers. + if (i == 3) find_tty_name(out, rdev); + + if (!strncmp(out, "/dev/", 5)) out += 5; } // TIME ELAPSED |