Contents
  1. 1. time
  2. 2. hyperfine
  3. 3. SHELL
  4. 4. code snippet

记录执行c代码和c程序的时间,benchmark执行时间。

time

命令行命令: time

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time yourscript.sh

hyperfine

安装:

有各种平台的安装,这里在Ubuntu上的安装:

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wget https://github.com/sharkdp/hyperfine/releases/download/v1.6.0/hyperfine_1.6.0_amd64.deb
sudo dpkg -i hyperfine_1.6.0_amd64.deb

命令执行

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hyperfine 'sleep 0.3'

这里默认执行benchmark10次,可以通过 -m/–min-runs 选项。

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hyperfine --min-runs 5 'sleep 0.2' 'sleep 3.2'

输出结果可以看到平均的执行时间。

SHELL

code snippet如下

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avg_time() {
#
# usage: avg_time n command ...
#
n=$1; shift
(($# > 0)) || return # bail if no command given
for ((i = 0; i < n; i++)); do
{ time -p "$@" &>/dev/null; } 2>&1 # ignore the output of the command
# but collect time's output in stdout
done | awk '
/real/ { real = real + $2; nr++ }
/user/ { user = user + $2; nu++ }
/sys/ { sys = sys + $2; ns++}
END {
if (nr>0) printf("real %f\n", real/nr);
if (nu>0) printf("user %f\n", user/nu);
if (ns>0) printf("sys %f\n", sys/ns)
}'
}

avg_time 5 sleep 1

运行此demo得到的结果如下:

real 1.000000
user 0.000000
sys 0.000000

code snippet

执行代码的秒数:

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#include <time.h>

clock_t begin = clock();

/* here, do your time-consuming job */

clock_t end = clock();
double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;

执行代码的毫秒数:

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#include <sys/time.h>

struct timeval tv1, tv2;
gettimeofday(&tv1, NULL);
/* stuff to do! */
gettimeofday(&tv2, NULL);

printf ("Total time = %f seconds\n",
(double) (tv2.tv_usec - tv1.tv_usec) / 1000000 +
(double) (tv2.tv_sec - tv1.tv_sec));
Contents
  1. 1. time
  2. 2. hyperfine
  3. 3. SHELL
  4. 4. code snippet