Unix – How to get a list of symbolic links, excluding broken links

symlinkunix

I have been able to find a command to get a list of the broken links only, but not the "working" symbolic links

find -H mydir -type l

How can I do the opposite?

If I have these files in mydir:

foo
bar
bob
carol

If they are all symbolic links, but bob points to a file that doesn't exist, I want to see

foo
bar
carol

Best Answer

With find(1) use

$ find . -type l -not -xtype l

This command finds links that stop being links after following - that is, unbroken links. (Note that they may point to ordinary or special files, directories or other. Use -xtype f instead of -not -xtype l to find only links pointing to ordinary files.)

$ find . -type l -not -xtype l -ls

reports where they point to.

If you frequently encounter similar questions in your interactive shell usage, zsh is your friend:

% echo **/*(@^-@)

which follows the same idea: Glob qualifier @ restricts to links, and ^-@ means "not (^) a link (@) when following is enabled (-).

(See also this post about finding broken links in python, actually this demonstrates what you can do in all languages under Linux. See this blog post for a complete answer to the related question of "how to find broken links".)

Related Solutions

Unix – How to list all cron jobs for all users

You would have to run this as root, but:

for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

will loop over each user name listing out their crontab. The crontabs are owned by the respective users so you won't be able to see another user's crontab w/o being them or root.

Edit if you want to know which user a crontab belongs to, use echo $user

for user in $(cut -f1 -d: /etc/passwd); do echo $user; crontab -u $user -l; done

Git – How does Git handle symbolic links

Git just stores the contents of the link (i.e. the path of the file system object that it links to) in a 'blob' just like it would for a normal file. It then stores the name, mode and type (including the fact that it is a symlink) in the tree object that represents its containing directory.

When you checkout a tree containing the link, it restores the object as a symlink regardless of whether the target file system object exists or not.

If you delete the file that the symlink references it doesn't affect the Git-controlled symlink in any way. You will have a dangling reference. It is up to the user to either remove or change the link to point to something valid if needed.

Best Answer

Related Solutions

Unix – How to list all cron jobs for all users

Git – How does Git handle symbolic links

Related Topic