Writing to an External File

Start with the open line.
Then, just use the print statement, followed by the filehandle, followed by the data you wish to print.
Finally, close the file so that others can use it.

open(DATA, ">>../userdata.txt") || &error;
print DATA "This is my input data.\n";
print DATA $inputData;
close(DATA);

You may want to lock this file so that it can be used by only one person at a time. To do so,

flock(DATA,2);

flock(DATA,8);