Bash: Parse the "Real" output of time of a command, check for output string, add time stamp and send it to an output file

Question

Not a script person. I am trying to build a repetitive test to see how long a command takes to run, marks if it's successful or not, and adds a time stamp, and appends everything to a log file.

Oh, and this is in bash on a mac.

To try to parse out just the "real" I've tried things like:

time ./login.sh | sed -n 's/.*real://p' >> output.txt

or

(time ./login.sh) 1> /dev/null 2> output.txt

The login.sh script runs, where it appends Succeeded or Failed:

application login -u "user" -p '******' "host.domain.com" | grep "Succeeded" &> /dev/null
if [ $? == 0 ]; then
    echo "  Suceeded" >> output.txt
else
    echo "  Failed" >> output.txt
fi

I'm going to put all of that into a For Loop with a sleep command so that it occurs every 5 minutes:

for n in {1..1000};
do
    # Command that Adds the time stamp
    # the command to find the real time above once I get it working
    sleep 5m
done

Desired Output would be akin to:

Sun Jul 29 16:15:06 PDT 2019 real   0m0.815s  Suceeded
Sun Jul 29 16:20:06 PDT 2019 real   0m0.635s  Suceeded
Sun Jul 29 16:25:06 PDT 2019 real   0m1.053s  Suceeded
Sun Jul 29 16:30:06 PDT 2019 real   0m15.653s  Failed

Answer 1

Use /usr/bin/time instead of the shell built-in time. Then capture the stderr into a separate file from the stdout of your application command. Since the elapsed real time is the first word of time's output, that's easy to grab with awk.

grep has a -q switch so no need to redirect to /dev/null.

Finally, sleep accepts an argument in seconds, so I don't think sleep 5m is going to do what you want. The syntax is accepted though, so I let it stand.

for n in {1..1000}
do

    /usr/bin/time application login -u "user" \
             -p '******' "host.domain.com" > login.out 2>time.out

    realtime=$(awk '{print $1}' time.out)

    echo -n "$(date) real $realtime " >> output.txt

    if grep -q "Succeeded" login.out; then
        echo "Succeeded" >> output.txt
    else
        echo "Failed"   >> output.txt
    fi

    sleep 5m

done

Answer 2

Don't grep/awk/sed, just use time's format options, e.g. time -f "%e" command will output just the elapsed real number of seconds the command took, and ONLY that.