Question

How does one say that their C program should accept a file list?

For example my program blah should accept hello.txt by the following call in the console:

blah hello.txt

I am not sure how to parse an argument and label it as a filepath (getopt doesn’t talk about this).

Answer 1

getopt() permutes argv[] so that all the non-options are shuffled to the end, so you simply call getopt() to parse all the options and then loop through argv[optind] up to argv[argc]. Those should be your file names, of course you need to check that those files actually exist, etc. C has no primitives for files. Here is some documentation about getopt().