posix_realpath: make sure we don't loop infinitely

On broken symlink loops this would never terminate. The most
naive and easy solution is a max of loop steps.
This commit is contained in:
Julian Ospald 2019-04-18 11:36:59 +08:00
parent 09abd528ee
commit 6e1ee078cc
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10
ghcup
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@ -1131,12 +1131,20 @@ get_distro_alias() {
# @STDOUT: realpath of the given file
posix_realpath() {
[ -z "$1" ] && die "Internal error: no argument given to posix_realpath"
current_loop=0
max_loops=50
mysource=$1
while [ -h "${mysource}" ]; do
current_loop=$((current_loop+1))
mydir="$( cd -P "$( dirname "${mysource}" )" > /dev/null 2>&1 && pwd )"
mysource="$(readlink "${mysource}")"
[ "${mysource%${mysource#?}}"x != '/x' ] && mysource="${mydir}/${mysource}"
if [ ${current_loop} -gt ${max_loops} ] ; then
(>&2 echo "${1}: Too many levels of symbolic links")
break
fi
done
mydir="$( cd -P "$( dirname "${mysource}" )" > /dev/null 2>&1 && pwd )"
@ -1149,7 +1157,7 @@ posix_realpath() {
echo "${mydir%/}/$(basename "${mysource}")"
fi
unset mysource mydir posix_realpath_error
unset current_loop max_loops mysource mydir
}