I have the following test script:
#!/bin/sh
testArray=(A,B,C,D,E)
currentValue=''
tempValue=x
for i in "${testArray[@]}"
do
currentValue=$i
echo "Processing " ${currentValue}
if [ ${currentValue}==A ]
then
tempValue="$i 123"
else
tempValue=$i
fi
echo "Current loop " ${tempValue}
echo `date`
done
When i test it, the output that i get is
Processing A,B,C,D,E
Current loop A,B,C,D,E 123
Mon Dec 2 20:33:26 GMT 2013
It looks like the 'for' loop in Bash works somehow differently to what i am used to as i was expecting the following output (ie whatever is in the 'for' loop to be repeated for each of the array elements)
Processing A
Current loop A 123
Mon Dec 2 20:29:44 GMT 2013
Processing B
Current loop B
Mon Dec 2 20:29:45 GMT 2013
Processing C
Current loop C
Mon Dec 2 20:29:46 GMT 2013
Processing D
Current loop D
Mon Dec 2 20:29:47 GMT 2013
Processing E
Current loop E
Mon Dec 2 20:29:48 GMT 2013
Basically what i am trying to achieve is to write a script that iterates through an array list and execute the same command based on different parameters dependent on the value of the current item in the array. I wrote the above script to try and understand how the for loop works but i am not getting the output i was expecting.
This line
testArray=(A,B,C,D,E)
creates an array with a single element, namely the string 'A,B,C,D,E'. Array elements are separated by whitespace, not commas. Use
testArray=(A B C D E)
You'll also need to add whitespace to your if
statement (and technically, you should use =
inside [...]
, not ==
, as well as quote the parameter expansion):
if [ "${currentValue}" = A ]
One more way
Change your loop to:
for i in `echo ${testArray} | tr "," " "`
As Suggested by chepner Change conditional statement to:
if [ "${currentValue}" = A ]
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