Create symbolic links to files using wildcards

Question

I want to create symlinks to multiple files:

ln -s dev-*.php 's/dev-(.*\.php)/$1/'

Results hoped for:  
    site.php links to dev-site.php  
    file.php links to dev-file.php

What's the most concise way to achieve this?

Solution 1

Well, if it's all in the same directory you could do something like this in bash or any other Bourne-style/POSIX shell:

for FILE in dev-*; do ln -s "$FILE" "${FILE#dev-}"; done

which would create symlinks without "dev-" to files beginning with "dev-".

Solution 2

I usually use a brief one-liner.

for file in dev-*.php; do ln -s $file $(echo "$file" | sed 's/^dev-//'); done

This cycles through the 'dev-*.php' files, getting the new name without 'dev-', then creating the symlink.

Solution 3

With zsh, you'd do:

autoload zmv # typically in ~/.zshrc
zmv -Lsv 'dev-(*.php)' '$1'

With bash or other POSIX shells (including zsh):

for f in dev-*.php; do
  ln -s "$f" "${f#dev-}"
done

Note that if site.php exists and is a directory (or a symlink to a directory), then you may end up with a dev-site.php symlink inside it. With GNU ln you could add the -T option to guard against that (with zmv use -o -T to pass the -T option down to ln).

Comments

[James Thompson]

Looks like the code formatter doesn't like the ${param#word} format. In this context the # is not treated as a comment but as an instruction to remove dev- from the value stored in FILE

[vonbrand]

Just have to take care with file names with funny characters... and the ${FILE#dev-} is a bashishm, AFAIU (definitely not in /bin/sh on Solaris way back).

[Stéphane Chazelas]

@vonbrand, ${FILE#dev-} is not Bourne, but is POSIX (was introduced by ksh, not bash). You need -- for ln to mark the end of options for a * pattern, or better, use a dev-* pattern. The code as it is would create symlinks to themselves in every subdirectory of the current directory whose name doesn't start with dev-. See also the notes in my answer.

[gbentley]

Thanks to all, for your help & explanations. Adding dev-* instead of * worked as intended here - as the code stands above it tries to create symlinks for every file.