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|
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
)
var KnowCommands = map[string]int{"exit": 0, "echo": 1, "type": 2}
func main() {
stdin := bufio.NewReader(os.Stdin)
for {
fmt.Fprint(os.Stdout, "$ ")
in, err := stdin.ReadString('\n')
if err != nil {
fmt.Println(err.Error())
}
trim := strings.TrimSpace(in)
command := strings.Split(trim, " ")
switch command[0] {
case "exit":
code, err := strconv.Atoi(command[1])
if err != nil {
fmt.Println(err.Error())
}
os.Exit(code)
case "echo":
fmt.Println(strings.Join(command[1:], " "))
case "type":
switch command[1] {
case "exit", "echo", "type":
fmt.Printf("%s is a shell builtin\n", command[1])
default:
env := os.Getenv("PATH")
paths := strings.Split(env, ":")
for _, path := range paths {
exec := path + "/" + command[1]
if _, err := os.Stat(exec); err == nil {
fmt.Printf("%s is %s", command[1], exec)
return
}
}
fmt.Printf("%s not found\n", command[1])
}
default:
fmt.Printf("%s: command not found\n", command[0])
}
}
}
|
