Remove use of deprecated ioutil functions from examples

examples/directories/directories.go

@@ -5,7 +5,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 )
@@ -32,7 +31,7 @@ func main() {
 	// Helper function to create a new empty file.
 	createEmptyFile := func(name string) {
 		d := []byte("")
-		check(ioutil.WriteFile(name, d, 0644))
+		check(os.WriteFile(name, d, 0644))
 	}
 
 	createEmptyFile("subdir/file1")
@@ -48,8 +47,8 @@ func main() {
 	createEmptyFile("subdir/parent/child/file4")
 
 	// `ReadDir` lists directory contents, returning a
-	// slice of `os.FileInfo` objects.
-	c, err := ioutil.ReadDir("subdir/parent")
+	// slice of `os.DirEntry` objects.
+	c, err := os.ReadDir("subdir/parent")
 	check(err)
 
 	fmt.Println("Listing subdir/parent")
@@ -64,7 +63,7 @@ func main() {
 
 	// Now we'll see the contents of `subdir/parent/child`
 	// when listing the *current* directory.
-	c, err = ioutil.ReadDir(".")
+	c, err = os.ReadDir(".")
 	check(err)
 
 	fmt.Println("Listing subdir/parent/child")

examples/reading-files/reading-files.go

@@ -8,7 +8,6 @@ import (
 	"bufio"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -24,7 +23,7 @@ func main() {
 
 	// Perhaps the most basic file reading task is
 	// slurping a file's entire contents into memory.
-	dat, err := ioutil.ReadFile("/tmp/dat")
+	dat, err := os.ReadFile("/tmp/dat")
 	check(err)
 	fmt.Print(string(dat))
 

examples/spawning-processes/spawning-processes.go

@@ -9,7 +9,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os/exec"
 )
 
@@ -46,7 +46,7 @@ func main() {
 	grepCmd.Start()
 	grepIn.Write([]byte("hello grep\ngoodbye grep"))
 	grepIn.Close()
-	grepBytes, _ := ioutil.ReadAll(grepOut)
+	grepBytes, _ := io.ReadAll(grepOut)
 	grepCmd.Wait()
 
 	// We omitted error checks in the above example, but

examples/temporary-files-and-directories/temporary-files-and-directories.go

@@ -8,7 +8,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 )
@@ -22,17 +21,17 @@ func check(e error) {
 func main() {
 
 	// The easiest way to create a temporary file is by
-	// calling `ioutil.TempFile`. It creates a file *and*
+	// calling `os.CreateTemp`. It creates a file *and*
 	// opens it for reading and writing. We provide `""`
-	// as the first argument, so `ioutil.TempFile` will
+	// as the first argument, so `os.CreateTemp` will
 	// create the file in the default location for our OS.
-	f, err := ioutil.TempFile("", "sample")
+	f, err := os.CreateTemp("", "sample")
 	check(err)
 
 	// Display the name of the temporary file. On
 	// Unix-based OSes the directory will likely be `/tmp`.
 	// The file name starts with the prefix given as the
-	// second argument to `ioutil.TempFile` and the rest
+	// second argument to `os.CreateTemp` and the rest
 	// is chosen automatically to ensure that concurrent
 	// calls will always create different file names.
 	fmt.Println("Temp file name:", f.Name())
@@ -49,10 +48,10 @@ func main() {
 
 	// If we intend to write many temporary files, we may
 	// prefer to create a temporary *directory*.
-	// `ioutil.TempDir`'s arguments are the same as
-	// `TempFile`'s, but it returns a directory *name*
+	// `os.MkdirTemp`'s arguments are the same as
+	// `CreateTemp`'s, but it returns a directory *name*
 	// rather than an open file.
-	dname, err := ioutil.TempDir("", "sampledir")
+	dname, err := os.MkdirTemp("", "sampledir")
 	check(err)
 	fmt.Println("Temp dir name:", dname)
 
@@ -61,6 +60,6 @@ func main() {
 	// Now we can synthesize temporary file names by
 	// prefixing them with our temporary directory.
 	fname := filepath.Join(dname, "file1")
-	err = ioutil.WriteFile(fname, []byte{1, 2}, 0666)
+	err = os.WriteFile(fname, []byte{1, 2}, 0666)
 	check(err)
 }

examples/writing-files/writing-files.go

@@ -6,7 +6,6 @@ package main
 import (
 	"bufio"
 	"fmt"
-	"io/ioutil"
 	"os"
 )
 
@@ -21,7 +20,7 @@ func main() {
 	// To start, here's how to dump a string (or just
 	// bytes) into a file.
 	d1 := []byte("hello\ngo\n")
-	err := ioutil.WriteFile("/tmp/dat1", d1, 0644)
+	err := os.WriteFile("/tmp/dat1", d1, 0644)
 	check(err)
 
 	// For more granular writes, open a file for writing.