Created
October 23, 2016 03:35
-
-
Save nimezhu/5d25e8c2adc91564c293703f8ba5aa60 to your computer and use it in GitHub Desktop.
Reading data from stdin or a file in Go
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| /* | |
| If no filename given as argument, read from stdin. Allows use as piped tool. | |
| mashbridge@hex iotest$ go build iotest.go | |
| mashbridge@hex iotest$ ./iotest x.txt | |
| file data: foo bar | |
| mashbridge@hex iotest$ ./iotest < x.txt | |
| stdin data: foo bar | |
| mashbridge@hex iotest$ echo "bingo" | ./iotest | |
| stdin data: bingo | |
| */ | |
| package main | |
| import ( | |
| "flag" | |
| "fmt" | |
| "io/ioutil" | |
| "os" | |
| ) | |
| func check(e error) { | |
| if e != nil { | |
| panic(e) | |
| } | |
| } | |
| func main() { | |
| flag.Parse() | |
| var data []byte | |
| var err error | |
| switch flag.NArg() { | |
| case 0: | |
| data, err = ioutil.ReadAll(os.Stdin) | |
| check(err) | |
| fmt.Printf("stdin data: %v\n", string(data)) | |
| break | |
| case 1: | |
| data, err = ioutil.ReadFile(flag.Arg(0)) | |
| check(err) | |
| fmt.Printf("file data: %v\n", string(data)) | |
| break | |
| default: | |
| fmt.Printf("input must be from stdin or file\n") | |
| os.Exit(1) | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment