$ zsh -c "ps aux | tee >(grep syslog) | awk 'NR == 1'"
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root       954  0.0  0.0  30180   476 ?        Ssl  Sep01   0:02 /sbin/rsyslogd -n -c 5
k         5479  0.0  0.0   4624   784 pts/0    S+   16:32   0:00 grep syslog
$ bash -c "ps aux | tee >(grep syslog) | awk 'NR == 1'"
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
$