chantools: replace deprecated ioutil functions

cmd/chantools/fakechanbackup.go

@@ -4,8 +4,8 @@ import (
 	"bytes"
 	"encoding/hex"
 	"fmt"
-	"io/ioutil"
 	"net"
+	"os"
 	"strconv"
 	"strings"
 	"time"
@@ -132,7 +132,7 @@ func (c *fakeChanBackupCommand) Execute(_ *cobra.Command, _ []string) error {
 	}
 
 	if c.FromChannelGraph != "" {
-		graphBytes, err := ioutil.ReadFile(c.FromChannelGraph)
+		graphBytes, err := os.ReadFile(c.FromChannelGraph)
 		if err != nil {
 			return fmt.Errorf("error reading graph JSON file %s: "+
 				"%v", c.FromChannelGraph, err)

cmd/chantools/forceclose.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"os"
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil/hdkeychain"
@@ -229,5 +229,5 @@ func forceCloseChannels(apiURL string, extendedKey *hdkeychain.ExtendedKey,
 	fileName := fmt.Sprintf("results/forceclose-%s.json",
 		time.Now().Format("2006-01-02-15-04-05"))
 	log.Infof("Writing result to %s", fileName)
-	return ioutil.WriteFile(fileName, summaryBytes, 0644)
+	return os.WriteFile(fileName, summaryBytes, 0644)
 }

cmd/chantools/rescueclosed.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"regexp"
 	"time"
 
@@ -204,7 +204,7 @@ func commitPointsFromDB(chanDb *channeldb.ChannelStateDB) ([]*btcec.PublicKey,
 }
 
 func commitPointsFromLogFile(lndLog string) ([]*btcec.PublicKey, error) {
-	logFileBytes, err := ioutil.ReadFile(lndLog)
+	logFileBytes, err := os.ReadFile(lndLog)
 	if err != nil {
 		return nil, fmt.Errorf("error reading log file %s: %w", lndLog,
 			err)
@@ -313,7 +313,7 @@ outer:
 	fileName := fmt.Sprintf("results/rescueclosed-%s.json",
 		time.Now().Format("2006-01-02-15-04-05"))
 	log.Infof("Writing result to %s", fileName)
-	return ioutil.WriteFile(fileName, summaryBytes, 0644)
+	return os.WriteFile(fileName, summaryBytes, 0644)
 }
 
 func rescueClosedChannel(extendedKey *hdkeychain.ExtendedKey,

cmd/chantools/root.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 	"time"
@@ -298,9 +298,9 @@ func (f *inputFlags) parseInputType() ([]*dataformat.SummaryEntry, error) {
 
 func readInput(input string) ([]byte, error) {
 	if strings.TrimSpace(input) == "-" {
-		return ioutil.ReadAll(os.Stdin)
+		return io.ReadAll(os.Stdin)
 	}
-	return ioutil.ReadFile(input)
+	return os.ReadFile(input)
 }
 
 func setupLogging() {

cmd/chantools/root_test.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"path"
 	"regexp"
@@ -52,8 +51,7 @@ func newHarness(t *testing.T) *harness {
 
 	buf := &bytes.Buffer{}
 	logBackend := btclog.NewBackend(buf)
-	tempDir, err := ioutil.TempDir("", "chantools")
-	require.NoError(t, err)
+	tempDir := t.TempDir()
 
 	h := &harness{
 		t:         t,

cmd/chantools/summary.go

@@ -3,7 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"time"
 
 	"github.com/lightninglabs/chantools/btc"
@@ -88,5 +88,5 @@ func summarizeChannels(apiURL string,
 	fileName := fmt.Sprintf("results/summary-%s.json",
 		time.Now().Format("2006-01-02-15-04-05"))
 	log.Infof("Writing result to %s", fileName)
-	return ioutil.WriteFile(fileName, summaryBytes, 0644)
+	return os.WriteFile(fileName, summaryBytes, 0644)
 }

cmd/chantools/zombierecovery_preparekeys.go

@@ -5,7 +5,6 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"time"
 
@@ -75,7 +74,7 @@ func (c *zombieRecoveryPrepareKeysCommand) Execute(_ *cobra.Command,
 		return fmt.Errorf("invalid payout address, must be P2WPKH")
 	}
 
-	matchFileBytes, err := ioutil.ReadFile(c.MatchFile)
+	matchFileBytes, err := os.ReadFile(c.MatchFile)
 	if err != nil {
 		return fmt.Errorf("error reading match file %s: %w",
 			c.MatchFile, err)