What does "-" mean in this linux command?
cat, linux
Solution
it is common to write `stdin` as dash (`-`).
even `man cat` mentions that:
With no FILE, or when FILE is -, read standard input.
and the manpage even has an example illustrating the use of dash and ordinary filenames (which is quite close to your original question, but includes the answer):
cat f - g
Output f's contents, then standard input, then g's contents.
Problem
I am learning the cat command of linux, and I found this command : ``` $ echo 'Text through stdin' | cat - file.txt ``` What does "-" mean here? If I don't type it , then 'Text through stdin' will not be shown.