TIMESTAMP(1)                                         TIMESTAMP(1)

          timestamp - log event times

          timestamp [ tag ]

          Timestamp reads lines from its standard input and writes
          them to its standard output, prefixing each line with the
          time that it was written, in decimal milliseconds since
          timestamp was started. If tag is given, it is written along
          with the time stamp on each line, to enable tagging if sev-
          eral writers are each writing to the same log file.

          The first line written gives the time that timestamp was
          started, in milliseconds since the epoch.  Note that logging
          events can cause timings to change, and that the timestamps
          are only as accurate as the times reported by /dev/time.


          % {echo hello; sleep 1; echo goodbye} | timestamp eg
          0000000000 eg start 1080156139468
          0000000007 eg hello
          0000000988 eg goodbye