On Thu, Aug 05, 1999 at 08:49:31AM +0200, Andreas Tille wrote:
> Hello,
>
> every time I read the bash manual to get help I'm missing
> examples for the basic usage of a builtin. For instance
> I managed to write a simple shell script with a loop which
> increased a variable
>
> i = 0;
> while [ $i -lt $MAX ] ; do
> echo $i
> let ...
> done
>
> But I havn't my small loop script handy this time and wanted
> to know the syntax of let using `man bash` or `info bash`.
> I'm I stupid or what is the reason that I can't find out, how
> this expression after let has to be formed?
1) For builtins bash has also help:
$ help let | less
2) Usage of man (my pager is `less')
$ man bash
/\<let\>
n
n
and I see
let arg [arg ...]
Each arg is an arithmetic expression to be evalu
ated (see ARITHMETIC EVALUATION). If the last arg
evaluates to 0, let returns 1; 0 is returned other
wise.
I go to top of manpage and issue new search:
<
/ARITHMETIC EVALUATION
and see detailed description.
3) Usage of info
$ info bash
^s let
^ ^
^---^------------------ here arre spaces
^s
and I see
`let'
let EXPRESSION [EXPRESSION]
The `let' builtin allows arithmetic to be performed on shell
variables. Each EXPRESSION is evaluated according to the rules
given below in *Note Shell Arithmetic::. If the last EXPRESSION
evaluates to 0, `let' returns 1; otherwise 0 is returned.
after that I go to topic "Shell Arithmetic".
Regards
Mirek
