Pretty Printing JSON on the Command Line with Go
As with other posts in this series, it's useful to be able to quickly convert a JSON string to a pretty-printed version.
In today's installment, we'll do it using Go.
Adapting the example from gosamples.dev, we can use the json.Indent call to perform the coercion, reading stdin using io.ReadAll, resulting in the following:
package main
import (
"bytes"
"encoding/json"
"fmt"
"io"
"os"
"strings"
)
func PrettyString(str []byte) (string, error) {
var prettyJSON bytes.Buffer
if err := json.Indent(&prettyJSON, str, "", " "); err != nil {
return "", err
}
return prettyJSON.String(), nil
}
func main() {
stdin, err := io.ReadAll(os.Stdin)
if err != nil {
panic(err)
}
res, err := PrettyString(stdin)
if err != nil {
panic(err)
}
fmt.Println(strings.TrimSuffix(res, "\n"))
}
This then allows us to convert:
{"key":[123,456],"key2":"value"}
To a pretty output:
go run main.go < file.json
