I have a relative path
$base_path = "input/myMock.TGZ";
Test whether something exists at given path using the
-e file-test operator.
print "$base_path exists!\n" if -e $base_path;
However, this test is probably more broad than you intend. The code above will generate output if a plain file exists at that path, but it will also fire for a directory, a named pipe, a symlink, or a more exotic possibility. See the documentation for details.
Given the extension of
.TGZ in your question, it seems that you expect a plain file rather than the alternatives. The
-f file-test operator asks whether a path leads to a plain file.
print "$base_path is a plain file!\n" if -f $base_path;
The perlfunc documentation covers the long list of Perl's file-test operators: