How to increment a bash variable (resulting from a command) inside a for loop

Question

I know that there are a lot of solutions on how to increment a variable inside a loop, but I'd like to know how to increment a variable which is a already a result from a command. Suppose I have files: test1 test2 test3 test4. My command is the following:

for i in {1..4}; do x$i=$(wc -l < test$i); done

I get:

x1=10: command not found

x2=9: command not found

x3=9: command not found

x4=9: command not found

which command could not be found? wc -l?

I guess the problem is related with the position of $symbol

The command not found is the one before the colon. So, x1=10, for example. This doesn't solve your problem, so this is just a comment for your future reference in command line or script debugging. — mrjink
– mrjink, Commented Sep 23, 2014 at 9:49

Mark Setchell · Accepted Answer · 2014-09-23 09:48:51Z

1

You can use declare built-in for this:

for i in {1..4}; do declare x$i=$(wc -l < test$i); done

edited Sep 23, 2014 at 9:48

Mark Setchell

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answered Sep 23, 2014 at 9:46

anubhava

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