diff options
| author | Thomas De Schampheleire | 2013-06-21 21:27:56 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2013-06-27 03:44:46 +0200 |
| commit | 879f008a8f890f83a005d0816d259c6157121e5b (patch) | |
| tree | c04cb9e6376d8eb18e17d19eaa9f8e35ce45a86b /procps | |
| parent | d66eb9042dcc6ee274949fb83612cecbbde44a4a (diff) | |
| download | busybox-879f008a8f890f83a005d0816d259c6157121e5b.zip busybox-879f008a8f890f83a005d0816d259c6157121e5b.tar.gz | |
lsof: correct check for symbolic link
Busybox lsof used the d_type field of a 'struct dirent' to verify whether the
entry is a symbolic link. This field, however, is not portable. On at least
one board [1] I have seen, that field is 0, and the check fails even though
the entry is a link.
The explicit check for a symbolic link is really only needed to skip the
default directory entries '.' and '..'. The directory /proc/<pid>/fd/
should not contain anything else but these two and symbolic links.
With these assumptions, this patch replaces the explicit link check with a
basic check for '.' and '..' (and any hidden file). In the unlikely case that
there are other file types, xmalloc_readlink() will return NULL, and we can
skip the entry.
[1] A MIPS-based board with glibc 2.9, Linux 2.6.32.27.
Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'procps')
| -rw-r--r-- | procps/lsof.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/procps/lsof.c b/procps/lsof.c index 7e0ffa4..b0156a5 100644 --- a/procps/lsof.c +++ b/procps/lsof.c @@ -61,9 +61,12 @@ int lsof_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) d_fd = opendir(name); if (d_fd) { while ((entry = readdir(d_fd)) != NULL) { - if (entry->d_type == DT_LNK) { - safe_strncpy(name + baseofs, entry->d_name, 10); - fdlink = xmalloc_readlink(name); + /* Skip entries '.' and '..' (and any hidden file) */ + if (entry->d_name[0] == '.') + continue; + + safe_strncpy(name + baseofs, entry->d_name, 10); + if ((fdlink = xmalloc_readlink(name)) != NULL) { printf("%d\t%s\t%s\n", proc->pid, proc->exe, fdlink); free(fdlink); } |