Bourne Shell (/bin/sh) counting?

[Jeff Beadles]

jsulliva at cvbnet.UUCP (Jeff Sullivan, x4096 MS 4-2) writes:

>  What is the best way to provide a loop counter in a Bourne
>  shell script? An example script is below, all it needs is
>  the count incrementer.

>      #!/bin/sh
>      count=0

>      for i in 1 2 3 4 5 6 7 8 9
>      do
>	# <increment count here>
>	echo count=$count
>      done

Well, the easiest way is to use expr.  Ie:

	count=0
	for i in 1 2 3 4 5 6 7 8 9 ; do
		count=`expr $count + 1`
		echo "Count is now $count"
	done

Note, that if you use expr, that special shell characters must be escaped.
This is bad and will cause you pain and suffering:
	count=`expr $count * 2`

This is fine and dandy and will make you a happy camper:
	count=`expr $count \* 2`



	-Jeff
-- 
Jeff Beadles				jeff at quark.WV.TEK.COM 
Utek Engineering, Tektronix Inc.	+1 503 685 2568
			"Credo quia absurdum"