readlink -f Command Reference for CI Scripts

readlink -f resolves all symlinks and returns a canonical absolute path.

readlink -f turns a relative or symlinked path into one canonical absolute path, which is what you want before changing directories or comparing paths in a script.

Common flags/usage

• -f: canonicalize, following every symlink (last component may not exist)
• -e: like -f but fail if the path does not exist
• -m: like -f but never check existence
• plain readlink LINK: print only the immediate symlink target
• realpath PATH: equivalent canonicalizer, often more portable

Example

REPO_ROOT=$(readlink -f "$(dirname "$0")/..")
echo "Building from ${REPO_ROOT}"

In CI

GNU readlink -f is on Linux runners but macOS\u2019s BSD readlink lacks -f; use realpath, or brew install coreutils for greadlink, when a workflow must run on macOS runners. Plain readlink without -f prints only one level of the symlink, not the fully resolved path.

Key takeaways

• readlink -f fully resolves symlinks into one canonical absolute path.
• macOS BSD readlink lacks -f; use realpath for portability.
• Plain readlink shows one symlink level, not the resolved path.

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