my_script in.file | other_process [>out.file]
    # no seg.fault

my_script < in.file | other_process [>out.file]
    # no seg.fault

my_script in.file [>out.file]
    # no seg.fault

my_script < in.file [>out.file]
Segmentation fault
    # or, equivalently:
cat in.file | my_script [>out.file]
Segmentation fault
    # seg.fault whether or not output is redirected;
    # output is always the same as in the first 3 cases