function surpress { /bin/rm --force /tmp/surpress.out 2> /dev/null; ${1+"$@"} > /tmp/surpress.out 2>&1 || cat /tmp/surpress.out; /bin/rm /tmp/surpress.out; }

surpress foo -a bar

OUTPUT=`tempfile`
program_we_want_to_capture &2>1 > $OUTPUT
[ $? -ne 0 ]; then
    cat $OUTPUT
    exit 1
fi
rm $OUTPUT

#!/bin/bash

the_command 2>&1 | awk '
BEGIN
{
  # Initialize our error-detection flag.
  ErrorDetected = 0
}
# Following are regex that will simply skip all lines
# which are good and we never want to see
/ Added UserList source/ ||
/ Added User/ ||
/ init domainlist / ||
/ init iplist / ||
/ init urllist / ||
/ loading dbfile / ||
/^$/ {next} # Uninteresting message.  Skip it.

# Following are lines that we good and we always want to see
/ INFO: ready for requests /
{
  print "  " $0 # Expected message we want to see.
  next
}

# any remaining lines are unexpected, and probably error messages.  These will be printed out and highlighted.
{
  print "->" $0 # Unexpected message.  Print it
  ErrorDetected=1
}

END
{
  if (ErrorDetected == 1) {
    print "Unexpected messages ("->") detected in execution."
    exit 2
  }
}
'
exit $?

out=`command args...` || echo $out