Calling a Bash function in a while loop

Question

I made this script which checks to make sure that an offshore script is created. I works ok &emdash; I put in a function to make it a little cleaner. But I don't think that the function works because it keeps on printing out the same time, in seconds.

#!/bin/bash
#set -x
check_offshore ()
{
    local RESULTS
    RESULTS=$(ssh -q -T casper@mybox "ls -ltr  /come/and/play/with/us/danny/DropBox| grep foreverr_and_$today.csv")
    rc=$?
}

today=$(/bin/date +%Y%m%d)
time=$(/bin/date +"%T.%3N")
iterate=0
while [ $iterate -le 5 ]
do
     check_offshore
     if [[ $rc != 0 ]] ; then
        echo "$time foreverr_and_$today.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox"
        fi
     sleep 5
     iterate=$((iterate+1 ))
     done

This is the log that it creates &emdash; the log time never changes. It stays the same, forever and ever and ever until the script stops.

17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox
17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox
17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox
17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox
17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox
17:42:28.380 foreverr_and_20150102.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox

What's up and how do I fix it?

Since you don't set time=$(...) inside the loop, how do you expect it to change? — Jonathan Leffler
– Jonathan Leffler, Commented Jan 2, 2015 at 23:13
If you're using Bash, you might prefer for ((iterate = 0; iterate <= 5; iterate++)) to control the loop. — Jonathan Leffler
– Jonathan Leffler, Commented Jan 2, 2015 at 23:14

Jonathan Leffler · Accepted Answer · 2015-01-02 23:34:53Z

4

Note that the problem has nothing to do with the function as such; the trouble is in the loop and its immediate surroundings.

Since you don't set time=$(...) inside the loop, how do you expect it to change?

Revise the loop so that the time is re-evaluated on each iteration. Since the date can change if you run this script after something like 23:59:30, you might also want to set the date on each iteration. You might also use a Bash-specific loop control mechanism:

for ((iterate = 0; iterate <= 5; iterate++))
do
    today=$(/bin/date +%Y%m%d)
    time=$(/bin/date +"%T.%3N")
    check_offshore
    if [[ $rc != 0 ]] ; then
       echo "$time foreverr_and_$today.csv is not present in casper@mybox:/come/and/play/with/us/danny/DropBox"
    fi
    sleep 5
done

You may prefer to stick with the original date, in which case you can continue to set today once outside the loop. Note that your logging becomes a little dubious if things go from 23:59:56.234 to 00:00:02.197 because things took a while just before midnight. Whether that matters to you or not is a judgement call you'll have to make. I recommend being unambiguous with the date+time in the log file; it is easier to diagnose what happened when several days later.

edited Jan 2, 2015 at 23:34

answered Jan 2, 2015 at 23:24

Jonathan Leffler

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1 Comment

capser Over a year ago

timmy () { time=$(/bin/date +"%Y%m%d-%T.%3N") } added a subroutine with the date and time - thank you

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