I see this symbol all the time and my book has yet to clarify what it means. None of the man pages or web searches clarify this either. At first I believed it to be a I/O symbol, but that never works when I try to play with it.
For example, in the
patch Man and Info documents, it say
You can also specify where to read the patch from with the '-i PATCHFILE' or '--input=PATCHFILE' option. If you do not specify PATCHFILE, or if PATCHFILE is
'-', 'path' reads the patch (that is, the 'diff' output) from the standard input.
When ever I see the '-' symbol, it is almost followed (at some point) by some mention of standard input.
What am I missing here? Does this symbol reference standard input? What does '-' mean in the context of Bash?