[PATCH] builtin: Fix seconds part of times(1)

[PATCH] builtin: Fix seconds part of times(1)

[Herbert Xu]

On Mon, Jun 10, 2019 at 02:07:11PM +0000, Michael Greenberg wrote:
>
> If folks are opposed to including math.h for some reason, I'm sure the
> computation could be done another way.

Thanks for the patch.  Yes I would like to avoid the libm dependency.
How about something like this:

---8<---
The seconds part of the times(1) built-in is wrong as it does not
exclude the minutes part of the result.  This patch fixes it.

This problem was first noted by Michael Greenberg who also sent
a similar patch.

Reported-by: Michael Greenberg <michael.greenberg@pomona.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/src/bltin/times.c b/src/bltin/times.c
index 8eabc1f..1166a68 100644
--- a/src/bltin/times.c
+++ b/src/bltin/times.c
@@ -15,16 +15,28 @@
 int timescmd() {
 	struct tms buf;
 	long int clk_tck = sysconf(_SC_CLK_TCK);
+	int mutime, mstime, mcutime, mcstime;
+	double utime, stime, cutime, cstime;
 
 	times(&buf);
-	printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n",
-	       (int) (buf.tms_utime / clk_tck / 60),
-	       ((double) buf.tms_utime) / clk_tck,
-	       (int) (buf.tms_stime / clk_tck / 60),
-	       ((double) buf.tms_stime) / clk_tck,
-	       (int) (buf.tms_cutime / clk_tck / 60),
-	       ((double) buf.tms_cutime) / clk_tck,
-	       (int) (buf.tms_cstime / clk_tck / 60),
-	       ((double) buf.tms_cstime) / clk_tck);
+
+	utime = (double)buf.tms_utime / clk_tck;
+	mutime = utime / 60;
+	utime -= mutime * 60.0;
+
+	stime = (double)buf.tms_stime / clk_tck;
+	mstime = stime / 60;
+	stime -= mstime * 60.0;
+
+	cutime = (double)buf.tms_cutime / clk_tck;
+	mcutime = cutime / 60;
+	cutime -= mcutime * 60.0;
+
+	cstime = (double)buf.tms_cstime / clk_tck;
+	mcstime = cstime / 60;
+	cstime -= mcstime * 60.0;
+
+	printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n", mutime, utime, mstime, stime,
+	       mcutime, cutime, mcstime, cstime);
 	return 0;
 }
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] builtin: Fix seconds part of times(1)

[Michael Greenberg]

Looks great! Thanks for getting to this. :)

Cheers,
Michael

On Mon, Jan 20 2020, Herbert Xu wrote:

> On Mon, Jun 10, 2019 at 02:07:11PM +0000, Michael Greenberg wrote:
>>
>> If folks are opposed to including math.h for some reason, I'm sure the
>> computation could be done another way.
>
> Thanks for the patch.  Yes I would like to avoid the libm dependency.
> How about something like this:
>
> ---8<---
> The seconds part of the times(1) built-in is wrong as it does not
> exclude the minutes part of the result.  This patch fixes it.
>
> This problem was first noted by Michael Greenberg who also sent
> a similar patch.
>
> Reported-by: Michael Greenberg <michael.greenberg@pomona.edu>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>
> diff --git a/src/bltin/times.c b/src/bltin/times.c
> index 8eabc1f..1166a68 100644
> --- a/src/bltin/times.c
> +++ b/src/bltin/times.c
> @@ -15,16 +15,28 @@
>  int timescmd() {
>         struct tms buf;
>         long int clk_tck = sysconf(_SC_CLK_TCK);
> +       int mutime, mstime, mcutime, mcstime;
> +       double utime, stime, cutime, cstime;
>
>         times(&buf);
> -       printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n",
> -              (int) (buf.tms_utime / clk_tck / 60),
> -              ((double) buf.tms_utime) / clk_tck,
> -              (int) (buf.tms_stime / clk_tck / 60),
> -              ((double) buf.tms_stime) / clk_tck,
> -              (int) (buf.tms_cutime / clk_tck / 60),
> -              ((double) buf.tms_cutime) / clk_tck,
> -              (int) (buf.tms_cstime / clk_tck / 60),
> -              ((double) buf.tms_cstime) / clk_tck);
> +
> +       utime = (double)buf.tms_utime / clk_tck;
> +       mutime = utime / 60;
> +       utime -= mutime * 60.0;
> +
> +       stime = (double)buf.tms_stime / clk_tck;
> +       mstime = stime / 60;
> +       stime -= mstime * 60.0;
> +
> +       cutime = (double)buf.tms_cutime / clk_tck;
> +       mcutime = cutime / 60;
> +       cutime -= mcutime * 60.0;
> +
> +       cstime = (double)buf.tms_cstime / clk_tck;
> +       mcstime = cstime / 60;
> +       cstime -= mcstime * 60.0;
> +
> +       printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n", mutime, utime, mstime, stime,
> +              mcutime, cutime, mcstime, cstime);
>         return 0;
>  }
> --
> Email: Herbert Xu <herbert@gondor.apana.org.au>
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