perl -e " print -t STDIN ? qq(STDIN has tty) : qq(NO tty associated);print ' - '; print -p STDIN ? qq(STDIN is a pipe or a named pipe) : qq(NOT a pipe)"

#out
#STDIN has tty - NOT a pipe


hostname | perl -e " print -t STDIN ? qq(STDIN has tty) : qq(NO tty associated);print ' - '; print -p STDIN ? qq(STDIN is a pipe or a named pipe) : qq(NOT a pipe)"

#out
#NO tty associated - STDIN is a pipe or anamed pipe