shell programming

["Jeremy C. Reed" <reed@wcug.wwu.edu>]

Does anyone know how I can combine a pipe with an "&&"?

I have a script that mails some piped input, but I don't want it to mail
if no has no data.

Is there a command for exiting if no stdin, but if there is just pipe it
through?

Well, here is my script:
#!/bin/sh

LOGFILE=/var/named/logs/logfile
MAILTO=jcr@iwbc.net
SUBJECT="dns problems report"

grep `date +"%d-%b-%Y"` $LOGFILE | \
  egrep 'reject|failed|error' | \
  cut -f 3-100 -d " " | \
  sort | \
  uniq | \
  mail -s "$SUBJECT" $MAILTO


Thanks,

  Jeremy C. Reed
  http://www.reedmedia.net
  http://bsd.reedmedia.net