time 函数
2、C++ Time
Example:
#include <iostream>
#include <chrono> //C++的`计时`库
#include <ctime>
long fibonacci(unsigned n)
{
if (n < 2) return n;
return fibonacci(n-1) + fibonacci(n-2);
}
int main()
{
std::chrono::time_point<std::chrono::system_clock> start, end;
start = std::chrono::system_clock::now();
std::cout << "f(42) = " << fibonacci(42) << '\n';
end = std::chrono::system_clock::now();
std::chrono::duration<double> elapsed_seconds = end-start;
std::time_t end_time = std::chrono::system_clock::to_time_t(end);
std::cout << "finished computation at " << std::ctime(&end_time)
<< "elapsed time: " << elapsed_seconds.count() << "s\n";
}
3、C语言 time
注意:now=$(date +"%T"),这里是T
,不是I
。
#!/bin/bash
# Purpose: Demo date command and menus
# Author: nixCraft <www.cyberciti.biz> under GPL v2.x+
# ------------------------------------------------------
# Display text at given row and column
show(){
local x=$1
local y=$2
local txt="$3"
# Set cursor position on screen
tput cup $x $y
echo "$txt"
}
while [ : ]
do
clear
# Get the system time
now="$(date +"%r")"
# Show main - menu, server name and time
show 10 10 "MAIN MENU for $HOSTNAME - $now"
show 11 10 "1. System info"
show 12 10 "2. Apache server stats"
show 13 10 "3. MySQL server stats"
show 14 10 "4. Firewall stats"
show 15 10 "5. Exit"
tput cup 16 10; read -t 2 -p "Choice [1-5] ? " usrch
# do something
case $usrch in
1) read -t 2 -p "Showing system info, wait..." fakeinput;;
2) read -t 2 -p "Showing apache info, wait..." fakeinput;;
3) read -t 2 -p "Showing mysqld info, wait..." fakeinput;;
4) read -t 2 -p "Showing firewall info, wait..." fakeinput;;
5) echo "Bye."; exit 0;;
esac
done
REFER: 16.3. Time / Date Commands