Re: portable implementation of load-average

[Stefan Monnier]

>        (let ((uptime (shell-command-to-string "/usr/bin/uptime")))

You probably want to use `call-process' here instead, so as to avoid running
`sh' (running `uptime' is already making your `load-average' much slower
than the C version, so I think it's important to try and limit the inflicted
pain).

Maybe caching, so as to only run `uptime' at most once every minute or so,
would be in order.

BTW, is /usr/bin/uptime setgid 0 on those systems, or does it use some other
method to get the info (a method that Emacs could maybe use)?

>          (if (string-match "load average: \\([0-9.]+\\), \\([0-9.]+\\), 
> \\([0-9.]+\\)" uptime)
>                  (if wantfloat
>                          (list
>                               (string-to-number (match-string 1 uptime))
>                               (string-to-number (match-string 2 uptime))
>                               (string-to-number (match-string 3 uptime))
>                               )
>                        (list
>                         (truncate (* 100 (string-to-number (match-string 1 
> uptime))))
>                         (truncate (* 100 (string-to-number (match-string 2 
> uptime))))
>                         (truncate (* 100 (string-to-number (match-string 3 
> uptime))))
>                         )
>                        )
>                (if wantfloat
>                        (list 0.0 0.0 0.0)
>                  (list 0 0 0)
>                  )
>                )

How 'bout:

  (mapcar (if wantfloat 'identity (lambda (x) (truncate (* 100 x))))
          (if (string-match "load average: \\([0-9.]+\\), \\([0-9.]+\\), 
\\([0-9.]+\\)" uptime)
              (mapcar (lambda (n) (string-to-number (match-string n uptime)))
                      '(1 2 3))
            '(0.0 0.0 0.0)))


-- Stefan