dex/schema/jsonfmt.go

54 lines
1.1 KiB
Go

// +build ignore
package main
import (
"bytes"
"encoding/json"
"io/ioutil"
"log"
"os"
)
func init() {
log.SetPrefix("fmtjson: ")
log.SetFlags(0)
}
func main() {
if len(os.Args) < 1 {
log.Fatal(`usage: go run jsonfmt.go [files...]
This is a small utility that standardizes the formatting of JSON files.
`)
}
for _, path := range os.Args[1:] {
data, err := ioutil.ReadFile(path)
if err != nil {
log.Fatalf("reading file %s: %v", path, err)
}
buff := new(bytes.Buffer)
if err := json.Indent(buff, data, "", " "); err != nil {
if err, ok := err.(*json.SyntaxError); ok {
// Calculate line number and column of error.
data := data[:err.Offset]
lineNum := 1 + bytes.Count(data, []byte{'\n'})
lastIndex := bytes.LastIndex(data, []byte{'\n'})
colNum := err.Offset
if lastIndex > -1 {
colNum = int64(len(data) - lastIndex)
}
log.Fatalf("file %s: invalid json at line %d, column %d: %v", path, lineNum, colNum, err)
}
log.Fatalf("file %s: invalid json: %v", path, err)
}
if err := ioutil.WriteFile(path, buff.Bytes(), 0644); err != nil {
log.Fatalf("write file %s: %v", path, err)
}
}
}