Hi,
readlink(1) has a check before calling readlink(2) that prints a
hand-rolled error message if your argument exceeds (PATH_MAX - 1)
bytes.
$ readlink $(perl -e 'print "z"x1024')
This contradicts the documentation, which says that absent the '-f'
flag nothing will be printed if the argument is not a symbolic link.
Exceeding (PATH_MAX - 1) bytes definitely excludes your argument, so
in that case readlink(1) should just say nothing.
With the '-f' option, readlink(1) already complains about an overlong
path or path component, so in that case the check is redundant.
$ readlink -f $(perl -e 'print "z"x256')
Without the '-f' flag this change would put us in sync with GNU
readlink's behavior. With the '-f' flag, it puts us in sync with GNU
realpath's behavior.
CC'd nicm@ because he expressed interest in this a few months back
when I submitted it as part of a larger patch that didn't make sense
in aggregate.
Thoughts?
--
Scott Cheloha
Index: usr.bin/readlink/readlink.c
===================================================================
RCS file: /cvs/src/usr.bin/readlink/readlink.c,v
retrieving revision 1.27
diff -u -p -r1.27 readlink.c
--- usr.bin/readlink/readlink.c 9 Oct 2015 01:37:08 -0000 1.27
+++ usr.bin/readlink/readlink.c 4 Sep 2017 15:57:47 -0000
@@ -64,14 +64,6 @@ main(int argc, char *argv[])
if (argc != 1)
usage();
- n = strlen(argv[0]);
- if (n > PATH_MAX - 1) {
- fprintf(stderr,
- "readlink: filename longer than PATH_MAX-1 (%d)\n",
- PATH_MAX - 1);
- exit(1);
- }
-
if (fflag) {
if (realpath(argv[0], buf) == NULL)
err(1, "%s", argv[0]);
