To run the perl file, just execute "/path/to/index.cgi" on the device.
This will actually allow to check multiple things:
- whether permissions are set correctly (i.e., file is executable). For
all cgi-bin implementations I know, files must be executable (i.e. "chmod 755 /path/to/index.cgi"
- whether the shebang is correct
- whether the perl contents of the file can actually be correctly evaluated. I'm pretty sure that you'll get something like "CGI.pm not found" (or similar).