语法

golang获取命令行参数及环境变量

package main
import "fmt"
import "os"
import "strconv"


func main() int{
    arg_num := len(os.Args)
    fmt.Printf("the num of input is %d\n",arg_num)

    fmt.Printf("they are :\n")
    for i := 0 ; i < arg_num ;i++{
        fmt.Println(os.Args[i])
    }

    sum := 0
    for i := 1 ; i < arg_num; i++{
        curr,err := strconv.Atoi(os.Args[i]) 
        if(err != nil){
            fmt.Println("error happened ,exit")
            return 1 
        }
        sum += curr
    }

    fmt.Printf("sum of Args is %d\n",sum)
    return 0
}

输出

manu@manu-hacks:~/code/go/self$ ./sum 1 2 4 
the num of input is 4
they are :
./sum
1
2
4
sum of Args is 7
manu@manu-hacks:~/code/go/self$ ./sum 1 2 4 f 5 
the num of input is 6
they are :
./sum
1
2
4
f
5
error happened ,exit

获取系统环境变量

package main
import "fmt"
import "os"

func main(){

    environ := os.Environ()
    for i := range environ {
        fmt.Println(environ[i])
    }
    fmt.Println("------------------------------------------------------------\n")
    logname := os.Getenv("LOGNAME")
    fmt.Printf("logname is %s\n",logname)
}

输出

manu@manu-hacks:~/code/go/self$ go run env.go 
SSH_AGENT_PID=2331
GPG_AGENT_INFO=/tmp/keyring-5CkALe/gpg:0:1
TERM=xterm
SHELL=/bin/bash
。。。

------------------------------------------------------------

logname is manu

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