UNIX for Dummies Questions & Answers

starttime=`date "+%s"`
Command1
endtime=`date "+%s"`
interval=`expr $endtime - $starttime`

if [ $interval -ge 3600 ]; then
  exit
fi

# subsequent commands

#!/bin/bash

/usr/bin/expect <<EOD

spawn Command1
set timeout 3600
expect {
         eof { exit 0 } 
	 timeout { exit 1 }
       }
EOD

status="$?"

if [ "$status" -eq 1 ]; then
    exit
else
   #continue
fi

$ cat timeout
#!/bin/ksh

##
##  timeout example
##

BACKGROUND_TIME=30  # Seconds the background process will run to simulate
                    #  a long-running process.
WAIT_TIME=20        # Seconds the main program will wait for the background process.
                    #  For an hour, use 3600.

##
##  Function to start the background process.
##
f_background_command() {
  print "  START - background_command, sleeping $BACKGROUND_TIME seconds..."
  ##  Simulate a long-running process.
  sleep $BACKGROUND_TIME
  print "  END - background_command"
}

##
##  Main
##
print "START"

## Start the background process...
f_background_command &

## And capture its PID.
background_PID=$!

print "background process PID is $background_PID"

## wait for the background command.
print "Waiting for $WAIT_TIME seconds"
sleep $WAIT_TIME

print "TIMEOUT reached"

##  If background command is still running, kill it.
if [[ -d "/proc/$background_PID" ]]; then
  kill -9 $background_PID 2>/dev/null  ## kill -9 could be dangerous!
  print "kill signal sent to PID $background_PID"
else
  print "Background process has already finished."
fi

print "END"

exit 0
$

$ cat timeout

#!/bin/ksh

##
##  timeout example
##

integer BACKGROUND_TIME=10  # Seconds the background process will run to simulate
                            #  a long-running process.
integer WAIT_TIME=30        # Max seconds the main program will wait for the background process.
                            #  For an hour, use 3600.
integer CHECK_TIME=2        # Seconds between checking to see if the process finished.
integer elapsed_time=0          # Total time we have waited.

##
##  Function to start the background process.
##
f_background_command() {
  print "  START - background_command, sleeping $BACKGROUND_TIME seconds..."
  sleep $BACKGROUND_TIME
  print "  \nEND - background_command"
}

##
##  Main
##
print "START"

## Start the background process...
f_background_command &

## And capture its PID.
background_PID=$!

print "background process PID is $background_PID"

print "Waiting for $WAIT_TIME seconds or until the process completes..."

## Wait until the background process finishes, or the timeout
##  has been reached.
while :
do
  sleep $CHECK_TIME

  if [[ ! -d "/proc/$background_PID" ]]; then
    print "Background process completed before WAIT_TIME reached."
    break
  fi
  if (( $elapsed_time > $WAIT_TIME )); then
    print "\nTimeout reached."
    kill $background_PID 2>/dev/null  ## kill -9 could be dangerous!
    print "kill signal sent to PID $background_PID"
    break
  fi

  (( elapsed_time = $elapsed_time + $CHECK_TIME ))

  printf "\rElapsed seconds: %d " $elapsed_time
done

print "\nEND"

exit 0

$  timeout
START
background process PID is 8048
Waiting for 30 seconds or until the process completes...
  START - background_command, sleeping 10 seconds...
Elapsed seconds: 8
   END - background_command
Background process completed before WAIT_TIME reached.

END
$

$ timeout
START
background process PID is 8186
Waiting for 10 seconds or until the process completes...
  START - background_command, sleeping 30 seconds...
Elapsed seconds: 12
Timeout reached.
kill signal sent to PID 8186

END
$