Question

I have a C codebase, all resides in the same directory.
I want to find all the header files that have a code file with the same name.

Right now, I have the following command:

ls *.h | sed s/.h/.c/

This returns a ‘list’ of filenames that I want to search for. How can I pass this list to another command so that I can see which header files have code files sharing the same name?

Answer 1

Without any external command:

$ for i in *.h
> do
>   [ -f  ${i/.h/.c} ] && echo $i
> done

The first line loops through every file.

The third line is a test construct. The -f flag to test (aka man [) checks to see if the file exists. If it does, it returns 0 (which is considered true in shell). The && only operates if the following command if the previous line returned successfully.

${i/.h/.c} is an in-place in-shell regex substitution so that the file tested is the corresponding .c to the .h.