Hi folks, Apologies if the following has already come up on this list; I looked for it and could not find any mention of it.
I noticed that in a GRUB script "[ -f <dangling symlink path> ]" evaluates to true. This is unlike the behavior of the "test" binary, in which it returns false: most file test operations dereference their symlinks recursively (i.e., strace on Linux reveals they use stat, which does this). By contrast, "[ -s <dangling symlink path> ]" evaluates to false, which seems inconsistent since if the file exists by -f, then it seems like -f is referring to the symlink itself, which has non-zero file size. I was curious whether there is some motivation with respect to any deviations that GRUB has in interpreting file test operations in comparison to the "test" binary, or whether this is considered a bug/thing that should be improved in the documentation. The GRUB manual ( http://git.savannah.gnu.org/cgit/grub.git/tree/docs/grub.texi) only indicates that -f tests whether the "file exists and is not a directory" without specifying the symlink behavior (unlike "man test"). Thanks, - Alan Note: To test how GRUB behaved here, I created a symlink /boot/grub/dangling_symlink that linked to "nowhere". Then I booted GRUB with config file: ... dangling_symlink_f=false if [ -f /boot/grub/dangling_symlink ] then dangling_symlink_f=true fi echo "dangling_symlink_f: $dangling_symlink_f" ... and streamed the serial console output from GRUB to obtain the value of $dangling_symlink_f. Similar can be done for "-s".
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