How to get readlink -e on M1 Macs which also works when used in bash scripts?

Question

I am using several bash scripts for build and deployment processes which use readlink with the -e option. Since this option is not available I followed this suggest to install coreutils and create a symbolink between greadlink and readlink. This worked perfectly on my Intel mac but when I recently switch to M1 mac I realized that the path to greadlink and readlink are changed so I tried this:

ln -s /opt/homebrew/bin/greadlink /usr/bin/readlink

Which gave me an error: Operation not permitted

I realised that this is because of the System Integrity Protection

How can I still use readlink -e in my bash scripts without deactivate the System Integrity Protection?

this works when I would use readlink in the terminal but not in a bash script — zlZimon, Dec 10 '22 at 15:03
It is just a matter of configuring your PATH env variable and creating a script named `readlink` with the content: `exec greadlink "$@"` with the proper shebang.. — Jetchisel, Dec 10 '22 at 15:08
This link might help: https://www.gnu.org/software/bash/manual/bash.html#Command-Search-and-Execution — Jetchisel, Dec 10 '22 at 15:12

Jetchisel · Accepted Answer · 2022-12-10T17:02:57.223

One approach is to create a script named readlink somewhere in your PATH with the following content.

#!/bin/sh

exec greadlink "$@"

Just make sure that the relative path of script named readlink comes before /usr/bin/ since the system readlink is in /usr/bin when you run:

declare -p PATH

or

echo "$PATH"

An example how to do it:

Create a directory in ~/, name it scripts since it will have script as contents.

mkdir -p ~/scripts

Edit ~/.bashrc to include the created directory in the PATH env variable.

if [[ :$PATH: != *:$HOME/scripts:* ]]; then
  PATH=$HOME/scripts:$PATH
fi

Source ~/.bashrc

source ~/.bashrc

Create a script name readlink inside the ~/scripts directory with the following contents:

#!/bin/sh

exec /opt/homebrew/bin/greadlink "$@"

Make it executable

chmod +x ~/scripts/readlink

Check which readlink is the first in PATH

type -a readlink

Output should be something like.

readlink is /home/zlZimon/scripts/readlink
readlink is /usr/bin/readlink

Note that the current work around is for a single user, or rather the user that has scripts directory in PATH, for a system wide approach one can use the path from homebrew or /usr/local/ or whichever default is available for all users.

How to get readlink -e on M1 Macs which also works when used in bash scripts?

1 Answers1