Question

I have written a large script to run a series of tests. Each test is a function on its own and I call these functions serially to get the job done.

I now want to make provisions to resume script run from the last function where it was aborted (e.g. in case system hangs). The logic I am using now is to write progress status into a file and then check the file content to determine where to start the script and resume from there.

However, I can’t continue using this logic because I want to introduce a menu into the script where I want to be able to choose from:

1) Run all tests from beginning to end
2) Run individual tests (brings up another menu with individual test options)
3) Resume from last abort

I have the written the code for the menu but still haven’t figured out how to fit my existing logic with the case construct used in my menu system. I am unhappy with the current resume from last abort logic I am using presently, which is:

fn1()
{
  #do a bunch of things
  echo 1 > progress.log
  fn2
}

fn2()
{
STATUS=`cat progress.log`
case "$STATUS" in 
1)
  #do a bunch of things
  echo 2 > progress.log
  fn3
;;
*)
 fn3
;;
esac
}

..
..
# and more functions in the same style as fn2
..

# main call

if [ -f progress.log ]
 fn2
else
 fn1
fi

Any ideas for a cleaner way to do this resume logic while integrating it with the ability to run tests individually when required? Thanks.

Answer 1

How about something like this. Drop the logic in fn1..N that link them together, but still write the progress.log file in there, and then do this:

runtest()
{
    # run test X where X is 1..N
    case "$1" in
    1) fn1 ;;
    2) fn2 ;;
    3) fn3 ;;
    *) echo "Invalid test number $1" ;;
    esac
}

runtests()
{
    START="$1"; shift
    [ -z "$START"] && START=1 # default to test 1
    for i in $(seq "$START" 50); do # replace 50 with max test number
        runtest $i
    done
}

# from your menu, run from start:
runtests 1
# from menu, run from progress
runtests $(< progress.log)
# from menu, run test TESTNUM
runtest $TESTNUM
# or by name (this is dangerous if you don't trust the user):
eval "$TESTNAME"

EDIT: with this version, you can just replace fn1, fn2, etc with the test names, so that you still get a runtest N interface that you can use to tie it all together.