- as a filename to mean stdin/stdout is a convention that a lot of programs use. It is not a special property of the filename. The kernel does not recognise
- as special so any system calls referring to
- as a filename will use
- literally as the filename.
With bash redirection,
- is not recognised as a special filename, so bash will use that as the literal filename.
cat sees the string
- as a filename, it treats it as a synonym for stdin. To get around this, you need to alter the string that
cat sees in such a way that it still refers to a file called
-. The usual way of doing this is to prefix the filename with a path -
/home/Tim/-. This technique is also used to get around similar issues where command line options clash with filenames, so a file referred to as
./-e does not appear as the
-e command line option to a program, for example.