Safely find files matching pattern and literals

Question

Given a filename like 'prefix.extension', I would like to find all files of the pattern prefix\\.\\d\\d\\.extension . Given that 'prefix' or 'extension' could contain literal strings like .* , \\n and the like, the only way I can think of finding this properly is to escape all characters in 'prefix' and 'extension', placing them before and after \\.\\d\\d\\. , and egrep -ing it. Is there a more elegant way of doing this and/or some simple way to escape all special characters for egrep in a Bash script?

Note that putting a backslash in front of every character will change the semantics of some, like \\w .

Answer 1

原来grep --perl-regexp与\\Q和\\E符合我的要求：

ls -1N -- "${source_dir}" | grep -P "^\Q${source_base}.\E\d\{${fragment_digits}\}\Q.${source_extensions}\E\$"