使用 rm 和 ls 时无法通过 SSH 删除目录

Question

I try to clean release directories when deploying code to the server, but I need to keep at least 5.

Now I use this command to do like I mentioned.

rm -rf $(ls -1t /path/to/deploy/release | tail -n +6)

Everything looks good when I ran this on the server, but It does not work when I try to run via ssh . . .

ssh user@123.456.789.100 'rm -rf $(ls -1t /path/to/deploy/release | tail -n +6)'

Anyone please help or suggest me. What am I do wrong?

Answer 1

Warning: like all things that involve rm -Rf and "should work", the below may actually delete all files on the computer (since ssh is involved, that's both the local and remote computers), and possibly set your kitchen on fire. I take no responsibility for damage etc... Backups (stored somewhere other than your kitchen) are always a good thing to have, and maybe you should test with rm -Ri first?

You don't say what the failure is, but one thing I notice is that the ls command will generate a list of filenames in the /path/to/deploy/release directory, but rm will not be running in that directory, so it's going to try to delete files by those names in your home directory instead of /path/to/deploy/release . This is fairly easy to fix by cd ing into that directory first (although be sure to write the command so if the cd fails, it won't just randomly delete files in the wrong directory).

Another problem is that the command depends on word splitting to turn the output of ls ... | tail ... ls ... | tail ... into a list of filenames, which will fail if any filenames contain whitespace and/or wildcards. This is trickier to solve, so I'll just ignore the problem and hope it never blows up on you.

Anyway, with the cd fix (and the whitespace bug unfixed), here's what I get:

ssh user@123.456.789.100 'cd /path/to/deploy/release && rm -Rf $(ls -1t | tail -n +6)'

Again, testing with rm -Ri (and having good backups) is recommended.