_sql := "select tid, bid, cover, title,limit_content,create_time,see,comment from blog where draft = '0' and title like CONCAT('%',?,'%') order by id desc limit ?,? "
// to do
rows, err := stmt.Query(title, (page-1)*FRONT_SIZE, FRONT_SIZE)
limit A, B: A是起始位置，等于(pageNum-1)*SIZE, B为SIZE（相当于步长）
实现前端分页API需要返回2个数据:
package main
import (
"github.com/scott-x/email"
"github.com/scott-x/randomCode"
)
func main() {
subject := "Slimx News"
body := `【温馨提示】：有人正在尝试访问你的博客， 验证码为: `
code, _ := randomCode.Random(6)
body += code
//send email
email.SendEmail(subject, body)
}
有这样的需求，我们把excel的数据存库了，可以直接调用，但是不排除中间修改数据的情况，如果excel被修改数据就不是最新的，所以，在拿到数据之前需要做时间上的对比
package main
import (
"log"
"os"
"time"
)
func main() {
log.Println(GetFileModTime("/Users/apple/desktop/a.txt"))
}
//获取文件修改时间 返回unix时间戳
func GetFileModTime(path string) int64 {
f, err := os.Open(path)
if err != nil {
log.Println("open file error")
return time.Now().Unix()
}
defer f.Close()
fi, err := f.Stat()
if err != nil {
log.Println("stat fileinfo error")
return time.Now().Unix()
}
return fi.ModTime().Unix()
}
获取程序的pid很有用
拿到pid之后，你就可以使用操作系统自带的命令来查看更多关于这个pid的信息, eg
ps -p pid -v
package main
import (
"fmt"
"os"
"os/exec"
"strconv"
)
func main() {
pid := os.Getpid()
fmt.Printf("Process PID: %d \n", pid)
prc := exec.Command("ps", "-p", strconv.Itoa(pid), "-v")
out, err := prc.Output()
if err != nil {
panic(err)
}
fmt.Println(string(out))
}
信号：操作系统和程序之间初级交流方式
它来自古老的c语言，可以通过man signal查看详情
信号列表：
常用的信号有：
SIGINT 和 SIGTERM 都是用来终端程序的SIGUP: 程序后台挂起Golang也可以处理信号， 示例如下：
package main
import (
"fmt"
"os"
"os/signal"
"syscall"
)
func main() {
// Create the channel where the received
// signal would be sent. The Notify
// will not block when the signal
// is sent and the channel is not ready.
// So it is better to
// create buffered channel.
sChan := make(chan os.Signal, 1)
// Notify will catch the
// given signals and send
// the os.Signal value
// through the sChan
signal.Notify(sChan,
syscall.SIGHUP,
syscall.SIGINT,
syscall.SIGTERM,
syscall.SIGQUIT,
syscall.SIGKILL)
// Create channel to wait till the
// signal is handled.
exitChan := make(chan int)
go func() {
signal := <-sChan
switch signal {
case syscall.SIGHUP:
fmt.Println("The calling terminal has been closed")
exitChan <- 0
case syscall.SIGINT:
fmt.Println("The process has been interrupted by CTRL+C")
exitChan <- 1
case syscall.SIGTERM:
fmt.Println("kill SIGTERM was executed for process")
exitChan <- 1
case syscall.SIGKILL:
fmt.Println("SIGKILL handler")
exitChan <- 1
case syscall.SIGQUIT:
fmt.Println("kill SIGQUIT was executed for process")
exitChan <- 1
}
}()
code := <-exitChan //here blocked
os.Exit(code)
}
运行代码，可以看到程序是被block住的:
通过按CTRL + C 发送SIGINT信号给程序, 程序退出
