I’d definitely choose C for such things because I want to know how things actually work, instead of doing a “cargo install” and then proceeding to read an API doc for two days.
I sympathise with that. But C is a bit low level to do a lot of messing about with strings. I'd use JavaScript myself. Python is a decent, but slow choice as well. C# and Java are also serviceable, but they're not trendy any more. Even a bash shell script would be ok.
You'll be doing a lot of tedious, error prone work to do this in C.
You'll be doing a lot of tedious, error prone work to do this in C.