How to check if a symlink exists
-L
returns true if the "file" exists and is a symbolic link (the linked file may or may not exist). You want -f
(returns true if file exists and is a regular file) or maybe just -e
(returns true if file exists regardless of type).
According to the GNU manpage, -h
is identical to -L
, but according to the BSD manpage, it should not be used:
-h file
True if file exists and is a symbolic link. This operator is retained for compatibility with previous versions of this program. Do not rely on its existence; use -L instead.
You can check the existence of a symlink and that it is not broken with:
[ -L ${my_link} ] && [ -e ${my_link} ]
So, the complete solution is:
if [ -L ${my_link} ] ; then
if [ -e ${my_link} ] ; then
echo "Good link"
else
echo "Broken link"
fi
elif [ -e ${my_link} ] ; then
echo "Not a link"
else
echo "Missing"
fi
-L
tests whether there is a symlink, broken or not. By combining with -e
you can test whether the link is valid (links to a directory or file), not just whether it exists.
-L is the test for file exists and is also a symbolic link
If you do not want to test for the file being a symbolic link, but just test to see if it exists regardless of type (file, directory, socket etc) then use -e
So if file is really file and not just a symbolic link you can do all these tests and get an exit status whose value indicates the error condition.
if [ ! \( -e "${file}" \) ]
then
echo "%ERROR: file ${file} does not exist!" >&2
exit 1
elif [ ! \( -f "${file}" \) ]
then
echo "%ERROR: ${file} is not a file!" >&2
exit 2
elif [ ! \( -r "${file}" \) ]
then
echo "%ERROR: file ${file} is not readable!" >&2
exit 3
elif [ ! \( -s "${file}" \) ]
then
echo "%ERROR: file ${file} is empty!" >&2
exit 4
fi
Maybe this is what you are looking for. To check if a file exist and is not a link.
Try this command:
file="/usr/mda"
[ -f $file ] && [ ! -L $file ] && echo "$file exists and is not a symlink"
How about using readlink
?
# if symlink, readlink returns not empty string (the symlink target)
# if string is not empty, test exits w/ 0 (normal)
#
# if non symlink, readlink returns empty string
# if string is empty, test exits w/ 1 (error)
simlink? () {
test "$(readlink "${1}")";
}
FILE=/usr/mda
if simlink? "${FILE}"; then
echo $FILE is a symlink
else
echo $FILE is not a symlink
fi