This will execute the given cmd while the given boolean returns true. The boolean has the same format as for the IF command, except that it is re-evaluated at each loop interation. The same is true for cmd. It is re-evaluated at each loop interation. Example (in script format):
alias repeat
{
@ rep = 0;
while (rep < [$0])
{
$1-
@ rep = rep + 1
}
assign -rep
}
This can be used as follows:
/repeat 10 /msg bigcheese This repeats 10 times
The repeat alias breaks down into three parts.
@ rep = 0
while (rep < [$0]) {$1-;@ rep = rep + 1}
assign -rep
The first is to initialize rep to 0 and the last part is to remove rep when done. The first is just like assign rep 0 The WHILE portion is described below: The boolean for the while loop is (rep < [$0]). This is what is then used at each loop interation. At the first iteration this will be ( 0<10 ), at the next ( 1<10 ), and so on. The cmd part of this looks like {$1-;@ rep = rep + 1} When the alias is first parsed, the stuff inside {..} is not expanded but is simply executed at each loop interation. It expands to
'msg bigcheese This repeats 10 times.;@ rep = rep + 1'
It sends the MSG to BigCheese and then it increments rep by 1.
(See @ for more information about this assignment)
The command part while is exactly like the syntax in if and foreach.
See Also: if foreach @ expressions