Re: [PATCH] maint.mk: print the elapsed time for each syntax-check rule

[Paolo Bonzini]

On 04/13/2010 10:41 AM, Pádraig Brady wrote:
> ts1=$(printf "%.2f\n" $(date +%s.%N) | tr -d .)
sleep 1.5
ts2=$(printf "%.2f\n" $(date +%s.%N) | tr -d .)
echo $(($ts2 - $ts1)) | sed 's/\(..\)$/.\1/'

Or somewhat creatively:

ts1=$(date +%s%N); ts1=${ts1%???????}
sleep 0.5
ts2=$(date +%s%N); ts2=${ts2%???????}
ts=$(($ts2 - $ts1 + 100))
echo $((${ts%??} - 1)).${ts:$((${#ts}-2))}

The last line is only half serious, but the first one is actually 
practical to use.

Paolo