ln

Make hardlinks and symlinks

This can also be done with cp

Hardlink:

ln <dest> [<name>]

If name is not given, use same basename as dest and create on current directory:

ln ../Makefile

Symlink files only:

ln -s dest name

Symlink dir:

ln -ds dest name

The link will be created even if the destination does not exist:

ln -s idontexist name

If the name is in another dir, the destination is not changed by default:

mkdir d
ln -s a d/a
[ `readlink d/a` = a ] || exit 1

To create relative to dest, use -r:

mkdir d
ln -rs a d/a
[ `readlink d/a` = ../a ] || exit 1

If the name is in another dir, the destination is not changed by default:

Absolute link:

ln /full/path/to/dest name
[ `readlink name` = "/full/path/to/dest" ] || exit 1

Trailing slash in link location

The following fails:

ln -s a b/

It seems that POSIX says that b/ is the same as b/., which must be a directory.

So in scripts that might take b/ (e.g. an input that comes from auto-completion), you have to do ${location%/}.