Re: [PATCH] mktempd: silence dd usage

[Jim Meyering]

Eric Blake wrote:
> When running a testsuite on FreeBSD, I saw a lot of:
>
> 1+ records in
> 0+1 records out
> 10 bytes transferred in 0.000063 secs (158875 bytes/sec)
>
> literring the testsuite, and traced it to the fact that we
> were silencing one, but not the other, dd usage in our fallback.
>
> * build-aux/mktempd (rand_bytes): Silence dd.
>
> Signed-off-by: Eric Blake <address@hidden>
> ---
>  ChangeLog         |    5 +++++
>  build-aux/mktempd |    3 ++-
>  2 files changed, 7 insertions(+), 1 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index fdf8b25..5a616e7 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,1 +1,6 @@
> +2011-12-01  Eric Blake  <address@hidden>
> +
> +     mktempd: silence dd usage
> +     * build-aux/mktempd (rand_bytes): Silence dd.
> +
>  2011-11-30  Simon Josefsson  <address@hidden>
>
>       manywarnings: Don't mention gcc version in docstring.
> diff --git a/build-aux/mktempd b/build-aux/mktempd
> index 7a09a4b..b6360e4 100755
> --- a/build-aux/mktempd
> +++ b/build-aux/mktempd
> @@ -30,35 +30,36 @@
>  #      the desired directory.
>  #  - make only $MAX_TRIES attempts
>
>  ME=`basename "$0"`
>  die() { echo >&2 "$ME: $@"; exit 1; }
>
>  MAX_TRIES=4
>
>  rand_bytes()
>  {
>    n=$1
>
>    chars=abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
>
>    dev_rand=/dev/urandom
>    if test -r "$dev_rand"; then
>      # Note: 256-length($chars) == 194; 3 copies of $chars is 186 + 8 = 194.
> -    dd ibs=$n count=1 if="$dev_rand" | tr -c $chars 
> 01234567$chars$chars$chars
> +    dd ibs=$n count=1 if="$dev_rand" 2>/dev/null \
> +      | tr -c $chars 01234567$chars$chars$chars

Thanks.

For the record, what version of FreeBSD was that?
I see that at least 9.0-BETA3 does have /usr/bin/mktemp.