└── tmp
file.go源码如下:
package main import ( "os" "log" ) func main(){ if(len(os.Args) < 3){ log.Fatal("Usage <command> <fileName> [data]"); } log.Printf("args:%s\n", os.Args); command := os.Args[1]; fileName := os.Args[2]; //打开文件 file, err := os.Open(fileName); if err != nil { log.Println(err) file, err = os.Create(fileName); if(err != nil){ log.Fatal(err) } } //查看文件属性 fileInfo, _ := file.Stat() log.Printf("name:%s, size:%d\n", fileInfo.Name(), fileInfo.Size()); switch command { case "read": buf := make([]byte, fileInfo.Size()) readSize, _ := file.Read(buf) log.Printf("readSize:%d\n", readSize) log.Print("bytes:%s\n", string(buf)); case "write": if len(os.Args) != 4 { MsgExit("Usage: <command> <file> <data>") } data := os.Args[3]; writeSize, err := file.WriteString(data); if err == nil{ log.Printf("wirte sucess!%d\n", writeSize) } } } func MsgExit( v ...interface{}){ //fatal 函数输出日志后,会调用系统的os.Exit(1) 推出程序. log.Fatal(v) }
编译和运行
go build -o bin/file src/file.go
gaojie@Joy:/media/gaojie/Linux/Go/workspace/file$ ./bin/file write tmp gaojie 2013/10/05 15:20:53 args:[./bin/file write tmp gaojie] 2013/10/05 15:20:53 name:tmp, size:3
gaojie@Joy:/media/gaojie/Linux/Go/workspace/file$ ./bin/file read tmp 2013/10/05 15:20:56 args:[./bin/file read tmp] 2013/10/05 15:20:56 name:tmp, size:3 2013/10/05 15:20:56 readSize:3 2013/10/05 15:20:56 bytes:%s xxx