1
In the cat man, it is specified :
Concatenate FILE(s) to standard output. With no FILE, or when FILE is -, read standard input.
cat - | encrypt | ...
in this example, cat will read from standard input. That's a popular convention, some other programs use it too, though it is not a standard.
another way to do it is from the /dev/stdin file :
cat /dev/stdin ...
Only top voted, non community-wiki answers of a minimum length are eligible
