This relative path to absolute path converter shell function
- requires no utilities (just
cd
andpwd
) - works for directories and files
- handles
..
and.
- handles spaces in dir or filenames
- requires that file or directory exists
- returns nothing if nothing exists at the given path
- handles absolute paths as input (passes them through essentially)
Code:
function abspath() {
# generate absolute path from relative path
# $1 : relative filename
# return : absolute path
if [ -d "$1" ]; then
# dir
(cd "$1"; pwd)
elif [ -f "$1" ]; then
# file
if [[ $1 = /* ]]; then
echo "$1"
elif [[ $1 == */* ]]; then
echo "$(cd "${1%/*}"; pwd)/${1##*/}"
else
echo "$(pwd)/$1"
fi
fi
}
Sample:
# assume inside /parent/cur
abspath file.txt => /parent/cur/file.txt
abspath . => /parent/cur
abspath .. => /parent
abspath ../dir/file.txt => /parent/dir/file.txt
abspath ../dir/../dir => /parent/dir # anything cd can handle
abspath doesnotexist => # empty result if file/dir does not exist
abspath /file.txt => /file.txt # handle absolute path input
Note: This is based on the answers from nolan6000 and bsingh, but fixes the file case.
I also understand that the original question was about an existing command line utility. But since this seems to be THE question on stackoverflow for that including shell scripts that want to have minimal dependencies, I put this script solution here, so I can find it later :)