is input from a pipe?

Not a question, but a quick note about a problem that sometimes pops up in
forums, that is how to detect on Linux if standard input (or any I/O
stream) is via pipe. My suggestion is to check if the stream is a FIFO, if
True it is a pipe, otherwise not a pipe

The solution that sometimes is proposed, that is

if not sys.stdin.isatty()

simply checks if the input is not from a terminal, but it may be from a
file, not only from a pipe.


import os
import sys
import stat
def check_if_stream_is_pipe(ifile):
    return stat.S_ISFIFO(os.fstat(ifile.fileno()).st_mode)

print(check_if_stream_is_pipe(sys.stdin))