Portability

‘input_line’ leaves a ‘\r’ (CR) character when reading lines from a Windows text file, whose lines end in “\r\n” (CRLF). This is a problem for any Windows file that is being read either on a Unix-like platform or on Windows in binary mode. If the code already takes care of removing any trailing ‘\r’ after reading the line, add a ’(* nosemgrep *)’ comment to disable this warning.

‘open_in’ behaves differently on Windows and on Unix-like systems with respect to line endings. To get the same behavior everywhere, use ‘open_in_bin’ or ‘open_in_gen [Open_binary]’. If you really want CRLF-to-LF translations to take place when running on Windows, use ‘open_in_gen [Open_text]’.

‘open_out’ behaves differently on Windows and on Unix-like systems with respect to line endings. To get the same behavior everywhere, use ‘open_out_bin’ or ‘open_out_gen [Open_binary]’. If you really want LF-to-CRLF translations to take place when running on Windows, use ‘open_out_gen [Open_text]’.

You should probably use Filename.get_temp_dirname().