Pattern: Missing use of ./* or -- in shell script
Issue: -
Since files and arguments are strings passed the same way, programs can't properly determine which is which, and rely on dashes to determine what's what.
A file named -f (touch -- -f) will not be deleted by the problematic code. It will instead be interpreted as a command line option, and rm will even report success.
Using ./* will instead cause the glob to be expanded into ./-f, which no program will treat as an option.
Similarly, -- by convention indicates the end of options, and nothing after it will be treated like flags (except for some programs possibly still special casing - as e.g. stdin).
Note that changing * to ./* in GNU Tar parameters will add ./ prefix to path names in the created archive. This may cause subtle problems (eg. to search for a specific file in archive, the ./ prefix must be specified as well). So using -- * is a safer fix for GNU Tar commands.
Example of incorrect code: rm *
Example of correct code:
rm ./*
or
rm -- *