File::Compare

Compares the contents of two sources, each of which can be a file or a filehandle. Returns if the sources are equal, if they are unequal, and -1 on error. File::Compare provides two functions.

cmp (file1, file2[, buffsize]) 

cmp is a synonym for compare. Exported on request.

compare (file1, file2[, buffsize]) 

Compares file1 to file2. Exported by default. If present, buffsize specifies the size of the buffer to use for the comparison.