How to add loop counter to foreach in csh

Question

In CSH foreach loop or for loop, how can I add a loop iterator or counter which increases from 10 to 1000 with steps of 20?

Something like foreach i (1..20..5) or for (i=1;i<20;i++).

Expect

Answer 1

If you have the seq command, you can use:

foreach i (`seq 1 5 20`)
  ... body ...
end

If you don't have seq, here is a version based on @csj's answer:

@ i = 1
while ($i <= 20)
  ... body ...
  @ i += 5
end

Creation

Or, for BSD and OS X: jot - 1 20 5 – Anglican

Answer 2

Any documentation I've found online seems to indictate no for loop is available. However, the while loop can be used. I don't actually know csh, so the following is approximate based on what I read:

set i = 10
while ($i <= 1000)
    # commands...
    set i = $i + 20
end

Cyclostyle

Actually, it'd be @ i = 1 and @ i = $i + 1 – Anglican

@Dennis Thanks for the syntax correction. As for the values, the question requests a counter that goes from 10 to 1000 in steps of 20. Thus, an initial value of 10, and + 20 each time through the loop. – Cyclostyle

The csh for loop is called with foreach. In fact, if you type "csh for" in the google search box, it shows foreach as the first option. – Pavid

Answer 3

Or you can use expr. the following worked for me (in tcsh but csh should be the same):

% set n=0
% foreach x (`ls $A*`)
foreach? set n=`expr $n + 1`
foreach? echo $n
foreach? end

output is 1 2 3 4 etc

Momentum