| tee | system | tee |
tee -- tee the standard output to a file
tee file
Tee copies its input to both the standard output and the named file. Its primary use is in pipes where one wants to capture some intermediate output.
1. The results of the set command are captured in the file "temp", and are also passed on to the "match" command. The result is a "temp" file of perhaps 100 lines, with the output to the screen only around 5 lines.
cl> set | tee temp | match tty
Since the processes in an IRAF pipe execute serially rather than concurrently, the teed output will not appear until all tasks to the left have completed.