varialbe increase 1 in shell script

yhus · 06-10-2006, 05:20 AM

Hello,

Is it possible to make a variable increased by 1 (like a++) in shell (bash) script? If it is, could you please give an example?

Thank you.

Jim

druuna · 06-10-2006, 05:35 AM

Hi,

This should work:

let counter="counter + 1"

Hope this helps.

Andrew Benton · 06-10-2006, 05:36 AM

Code:

((count++))

Or in a script

Code:

count=0
while [[ $((count++)) -lt 40 ]]
do
  if dmesg | grep 'ADSL line is up'
  then
     pppd call ISP
     exit 0
  fi
  sleep 1
done

AnanthaP · 06-10-2006, 06:42 AM

a=0
a=$a + "expr 1"

AFAIK, `expr` is one way to achieve this.

End

dive · 06-10-2006, 11:08 AM

Or yet another way:

counter=$[counter+1]

and probably

counter=$[counter++]