Working with dashed filename in Linux requires some attention.
Dash (-) character at the end of the commands is a popular convention to refer stdin or stdout. Dash is not a special character for filesystem or kernel.
But, if you accidently create a file which begins with a dash (-) character, you’ll be realize that you can’t simply delete this file with regular
rm -f -testfile
rm: invalid option -- t
Because of the first character is a dash, shell thinks we want to provide an option to rm command itself. To solve this problem you have to use double dash character
-- after our command’s options are finished:
rm -f -- -testfile
-- character seen, shell thinks that optional arguments for command itself finished and doesn’t make option parsing anymore.
Another solution for this problem, using
./ convention to refer filenames. For example you can repeat above example:
rm -f ./-testfile
This solution also works because command line option parsing ends when a
./ pattern received.
For the stdin and stdout effect, we can use /dev/stdin and /dev/stdout files. They are just symlinks to /proc/self/fd/0 and /proc/self/fd/1 so you can use like this:
echo test /dev/stdout
cat < /dev/stdin