Convert all the newlines in a file from \r\n to \n Inspired by what I'm doing at work right now.
Your program should take one parameter, the path to the file
It should convert all the windows style newlines (\r\n) to unix style (\n) and write the result back to the file
APL (Dyalog Unicode), 22 bytes

Anonymous tacit prefix function.
10@3∘⎕NGET⎕NPUT{⍵1}

Try it online!
⎕NGET get content,encoding,line-ending from argument file
10@3∘ replace the third element (line ending) with 10, meaning \n
⎕NPUT put that into…
{⍵1} the file name followed by an overwrite flag