I'm currently working on a script in which I want to use an array length as a conditional argument. I can get the length of the array like this:
myarr=$(squeue | grep cjones903 | awk '{print $3}' )
echo ${#myarr}
but this wont work because I need the length to be evaluated iteratively in order to continue when the length drops below a threshold.
I would like to be able to do this:
while [ length is > x] do;
sleep 60;
else:
OK, since we seemed to have whittled it down in the comments to a way to check the number of jobs running by checking the number of lines returned by your squeue call, here is a little script I was tinkering with during the discussion. Take any further ideas you can from it. One thing to further look into is a lock file (or lock dir) to insure only one instance of the script runs at a time (many examples already on StackOverflow). Good luck:
#!/bin/bash
## consider setting lock file so only 1 instance runs
# (many examples on SO)
## simple declarations
declare -i threshold=10 ## your limit, njobs above, sleep
declare -i njobs="$threshold" ## threshold number of jobs limit
declare -i nseconds=60 ## seconds to sleep
while :; do ## outer loop - runs perpetually
njobs=$(squeue | grep cjones903 | wc -l) ## get no. of jobs
while ((njobs > threshold)); do ## test
sleep "$nseconds" ## sleep if above
njobs=$(squeue | grep cjones903 | wc -l) ## get no. of jobs
fi
## code to submit new batch of jobs here
# sleep a couple to let jobs distribute
done
exit 0
${#arrayname[@]}in bash. You can iterate over an array withfor ((i = 0; i < ${#arrayname[@]}; i++)); do ...(where$i=0, 1, 2, ...) or withfor i in "${arrayname[@]}"; do...where ($i=element1, element2, ...) There is no need for a conditional.(squeue | grep cjones903 | awk '{print $3}' )iteratively. After it drops below a certain count, I want to be able to continue my loop.${#myarray[@]} > x. Now as written above,myarris a string variable, not an array, so the length would simply be${#myarr} > x. To makemyarran array, you would needmyarr=( $(squeue | grep cjones903 | awk '{print $3}' ) )${#myarr}it will compute the length at that point. If you give a fuller example showing what you are trying to do, I can most likely show you how or give you a definitive on whether it is possible. Oh, also, your comparison should use the-gtor-lt, etc. numeric comparisons.