Rm failing inside cron script

cron

I have a cron job calling a bash script which runs fine, except for one line inside it that is suppose to remove all fines in a directory. The result of this line is always 'no such file or directory' even though I have verified (many times) that there are files in that directory. The line in question is as simply:

rm /dir1/dir2/dir3/*

The script works fine when run manually in the terminal, so it must be something about how the cron is run. I've tried giving 'dir3' and all the files inside it every permission possible, so it shouldn't be a permission problem. (The directory and files are also owned by the user). I've tried specifing 'SHELL=/bin/bash' inside 'crontab'. There is no sticky bit set and there is no alias on the rm command.

Interestingly changing the 'rm' command to 'ls' gives the same negative result (unless you remove the trailing '*', and then that works).

What am I missing here?

Best Answer

Turned out to be my bad after all. What I actually had in the script was:

rm "/dir1/dir2/dir3/*"

I didn't realise that the quotes would be blocking the wildcard expansion so I never included them in the question. Removing the quotes fixed the problem, as I'm sure would have been pointed out to me if I'd included them. Although I'm not 100% sure how one is supposed to handle spaces in the path without the quotes thought.

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Macos – git push to github via cron on mac

TL;DR: Solved problems with git push via cron by using SSH instead of HTTPS.

Thanks to the support team at GitHub I was able to solve this.

The first problem was that git-credential-osxkeychain was not in my path when the cron job ran. For me, git and git-credential-osxkeychain were both being run out of the Xcode command line tools directory:

$ which git
/Applications/Xcode.app/Contents/Developer/usr/bin/git
$ which git-credential-osxkeychain
/Applications/Xcode.app/Contents/Developer/usr/bin/git-credential-osxkeychain

When running which git from cron, turns out cron was running git from /usr/bin.

I added the appropriate directory to my PATH at the top of the cron job with:

export PATH=$PATH:/Applications/Xcode.app/Contents/Developer/usr/bin

That solved the git: 'credential-osxkeychain' is not a git command error, but I got yet another error:

fatal: could not read Username for 'https://github.com': Device not configured

At the suggestion of the GitHub support team, I solved the problem (without the need for git-credential-osxkeychain at all) by authenticating via SSH instead of https:

git remote set-url origin git@github.com:username/repo.git

Linux – does this script fail when run from cron, but works when run manually

The usual answer to this type of question is that cron jobs are run in non-interactive, non-login shells, so most of your shell startup files (both the systemwide ones in /etc and your personal dotfiles in your home directory) are not sourced (read in and executed), because most shell startup files apply to login shells (the first shell you see when you log into the computer), or interactive shells (shells that are connected to terminals, ssh sessions, or terminal emulators because a user is interacting with them via said terminal).

So if you put a command in a cron job that actually depends on some environment setup (including PATH changes) that usually happens in places like /etc/profile, /etc/bashrc, ~/.profile, or ~/.bashrc, that setup won't happen for a cron job. The cron file format does allow you to specify environment variables for your jobs, so you might want to specify BASH_ENV or ENV to point it at a shell startup script to source. See the "Invocation" section of the bash(1) man page.

Best Answer

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Macos – git push to github via cron on mac

Linux – does this script fail when run from cron, but works when run manually

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