A pipeline consists of one or more commands separated by a pipe symbol (|). The shell connects standard output (and optionally standard error) of the command preceding the pipe symbol to standard input of the command following the pipe symbol. A pipeline has the same effect as redirecting standard output of one command to a file and then using that file as standard input to another command. A pipeline does away with separate commands and the intermediate file. The syntax of a pipeline is
command_a [arguments] | command_b [arguments]
The preceding command line uses a pipeline to effect the same result as the following three commands:
command_a [arguments] > tempcommand_b [arguments] < temprm temp
In the preceding sequence of commands, ...