Real Path of a Symbolic Link

03 May, 2010
shellscript, tips

I needed to figure out the real path of a symbolic link to a file for a script so that i could set the parent dir of the file as home.

The file (ec2-version) was linked into /usr/local/bin but I needed the path to ec2-tools home. 

# filename : realpath

# which file is found in the exec path
binpath=$(which $1) 
# ls -l gives 
# lrwxr-xr-x  1 briandemant  wheel  49 Mar  5 11:32                         \ 
#              /usr/local/bin/ec2-version -> ../ec2-api-tools/bin/ec2-version 
# I only need the last after '-> '
realfile=$(ls -l $binpath | egrep -o "[^> ]+$") 

# as the link can be relative we need to be in the link dir
cd $(dirname $binpath)

# and from there go to the dir of the realfile
cd $(dirname $realfile) 

# now we can return the fullpath to the real file
echo $(pwd)/$1