So yes, it's perfectly safe to have spaces and other shell metacharacters in there. You could (for instance) probe content of system files by passing -f/som

So yes, it's perfectly safe to have spaces and other shell metacharacters in there. You could (for instance) probe content of system files by passing -f/some/file And matching that to the log. If you have some control over the log, you could use this to read content from system files. Of course, it's all indirect, since the file is interpreted as containing regular expressions. But it's certainly not 'perfectly safe'.