Files
cid/cid-fmt/main.go
2018-08-09 02:37:09 -04:00

129 lines
2.6 KiB
Go

package main
import (
"fmt"
"os"
"strings"
c "github.com/ipfs/go-cid"
mb "github.com/multiformats/go-multibase"
)
func usage() {
fmt.Fprintf(os.Stderr, "usage: %s [-b multibase-code] [-v cid-version] <fmt-str> <cid> ...\n\n", os.Args[0])
fmt.Fprintf(os.Stderr, "<fmt-str> is either 'prefix' or a printf style format string:\n%s", c.FormatRef)
os.Exit(2)
}
func main() {
if len(os.Args) < 2 {
usage()
}
newBase := mb.Encoding(-1)
var verConv func(cid *c.Cid) (*c.Cid, error)
args := os.Args[1:]
outer:
for {
switch args[0] {
case "-b":
if len(args) < 2 {
usage()
}
encoder, err := mb.EncoderByName(args[1])
if err != nil {
fmt.Fprintf(os.Stderr, "Error: %s\n", err.Error())
os.Exit(2)
}
newBase = encoder.Encoding()
args = args[2:]
case "-v":
if len(args) < 2 {
usage()
}
switch args[1] {
case "0":
verConv = toCidV0
case "1":
verConv = toCidV1
default:
fmt.Fprintf(os.Stderr, "Error: Invalid cid version: %s\n", args[1])
os.Exit(2)
}
args = args[2:]
default:
break outer
}
}
if len(args) < 2 {
usage()
}
fmtStr := args[0]
switch fmtStr {
case "prefix":
fmtStr = "%P"
default:
if strings.IndexByte(fmtStr, '%') == -1 {
fmt.Fprintf(os.Stderr, "Error: Invalid format string: %s\n", fmtStr)
os.Exit(2)
}
}
for _, cidStr := range args[1:] {
cid, err := c.Decode(cidStr)
if err != nil {
fmt.Fprintf(os.Stdout, "!INVALID_CID!\n")
errorMsg("%s: %v", cidStr, err)
// Don't abort on a bad cid
continue
}
base := newBase
if newBase == -1 {
base, _ = c.ExtractEncoding(cidStr)
}
if verConv != nil {
cid, err = verConv(cid)
if err != nil {
fmt.Fprintf(os.Stdout, "!ERROR!\n")
errorMsg("%s: %v", cidStr, err)
// Don't abort on a bad conversion
continue
}
}
str, err := c.Format(fmtStr, base, cid)
switch err.(type) {
case c.FormatStringError:
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
os.Exit(2)
default:
fmt.Fprintf(os.Stdout, "!ERROR!\n")
errorMsg("%s: %v", cidStr, err)
// Don't abort on cid specific errors
continue
case nil:
// no error
}
fmt.Fprintf(os.Stdout, "%s\n", str)
}
os.Exit(exitCode)
}
var exitCode = 0
func errorMsg(fmtStr string, a ...interface{}) {
fmt.Fprintf(os.Stderr, "Error: ")
fmt.Fprintf(os.Stderr, fmtStr, a...)
fmt.Fprintf(os.Stderr, "\n")
exitCode = 1
}
func toCidV0(cid *c.Cid) (*c.Cid, error) {
if cid.Type() != c.DagProtobuf {
return nil, fmt.Errorf("can't convert non-protobuf nodes to cidv0")
}
return c.NewCidV0(cid.Hash()), nil
}
func toCidV1(cid *c.Cid) (*c.Cid, error) {
return c.NewCidV1(cid.Type(), cid.Hash()), nil
}