ln -s Command Reference for CI Scripts

ln -s creates a symbolic link that points at another path.

Symlinks let CI pin a stable name to a versioned install (a "current" toolchain) or expose a binary on PATH. The relative-vs-absolute target choice trips people up.

Common flags/usage

-s: make a symbolic (not hard) link
-f: remove an existing destination first
-n: treat an existing symlink destination as a normal file, not a dir
-r: make the link target relative (GNU)
ln -s TARGET LINKNAME: TARGET first, then the new link name

Example

shell

ln -sfn "/opt/node/${NODE_VERSION}" /opt/node/current
ln -sf "${PWD}/bin/tool" /usr/local/bin/tool

In CI

Use ln -sfn together when repointing a "current" symlink: -f replaces it and -n stops ln from descending into the old link and creating a nested link instead. A relative target (or -r) keeps the link valid if the tree is moved or mounted at a different prefix; an absolute target breaks then.

Key takeaways

ln -s TARGET LINK takes the target first, then the new link name.
ln -sfn safely repoints an existing "current" symlink in place.
Relative targets survive a moved or remounted tree; absolute ones may not.

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