subtracting variables in ksh

cesarNZ · #1 (**permalink**) 10-09-2008

hi all,
how do i subract variables in shell ?? am trying to space out the headers and the output generated by the shell so they all line up :

currently the output is like this :

servers : users

server1 : 10
latestServer : 50

so i thought i would keep a constant e.g 40 and subtract the length of the server name from it.

count=${#myserver}; <-- this is the length of the server name
spaces=((40 - $count )); <-- this doesnt really work

thanks in advance.

vidyadhar85 · #2 (**permalink**) 10-09-2008

you were almost there

Code:

spaces=$((40-$count))

a2156z · #3 (**permalink**) 10-09-2008

((spaces=40-count))

cfajohnson · #4 (**permalink**) 10-10-2008

Quote:

Originally Posted by a2156z

((spaces=40-count))

That is non-standard. For example:

Code:

$ count=3
$ ((spaces=40-count))
$ printf ":%s:\n" "$spaces"
::
$ spaces=$((40 - $count))
$ printf ":%s:\n" "$spaces"
:37:

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