This is an example of using a unix pipe to compress an Oracle export on-the-fly. This is useful when disk space is tight and when there are multiple CPUs.
When the export is running, do a top/prstat and watch how exp and compress both get CPU.
This is from a unix shell. Shell environment and PATHs are configured.
$ mknod mypipe p
$ /usr/bin/compress < mypipe > fullexp.SID.`date +%m%d`.dmp.Z &
$ $ORACLE_HOME/bin/exp userid=/ full=y file=mypipe log=fullexp.SID.`date +%m%d`.log direct=y consistent=n
$ rm mypipe