Simplify IO

Author: stilvoid

cmd/identify/identify.go

@@ -2,18 +2,18 @@ package identify
 
 import (
 	"fmt"
-	"os"
 
 	"github.com/spf13/cobra"
 	"github.com/stilvoid/please"
+	"github.com/stilvoid/please/internal"
 )
 
 var Cmd = &cobra.Command{
-	Use:   "identify [filename]",
-	Short: "Identify the format of some structured data",
-	Args:  cobra.ExactArgs(1),
+	Use:   "identify (FILENAME)",
+	Short: "Identify the format of some structured data from FILENAME or stdin if omitted",
+	Args:  cobra.RangeArgs(0, 1),
 	Run: func(cmd *cobra.Command, args []string) {
-		data, err := os.ReadFile(args[0])
+		data, err := internal.ReadFileOrStdin(args...)
 		cobra.CheckErr(err)
 
 		format, _, err := Identify(data)

cmd/parse/parse.go

@@ -1,14 +1,13 @@
 package parse
 
 import (
-	"errors"
 	"fmt"
-	"os"
 
 	"github.com/jmespath/go-jmespath"
 	"github.com/spf13/cobra"
 	"github.com/stilvoid/please"
 	"github.com/stilvoid/please/cmd/identify"
+	"github.com/stilvoid/please/internal"
 )
 
 var inFormat string
@@ -24,8 +23,8 @@ func init() {
 }
 
 var Cmd = &cobra.Command{
-	Use:   "parse [filename]",
-	Short: "Parse and convert structured data",
+	Use:   "parse (FILENAME)",
+	Short: "Parse and convert structured data from FILENAME or stdin if omitted",
 	Args:  cobra.RangeArgs(0, 1),
 	Run: func(cmd *cobra.Command, args []string) {
 		if listMode {
@@ -39,12 +38,10 @@ var Cmd = &cobra.Command{
 				fmt.Printf("  %s\n", name)
 			}
 			return
-		} else if len(args) != 1 {
-			cobra.CheckErr(errors.New("You must supply a filename"))
 		}
 
-		// Read from stdin
-		input, err := os.ReadFile(args[0])
+		// Read from stdin?
+		input, err := internal.ReadFileOrStdin(args...)
 		cobra.CheckErr(err)
 
 		// Try parsing

cmd/respond/respond.go

@@ -9,9 +9,7 @@ import (
 	"net"
 	"net/http"
 	"net/textproto"
-	"os"
 
-	"github.com/andrew-d/go-termutil"
 	"github.com/spf13/cobra"
 	"github.com/stilvoid/please/internal"
 )
@@ -30,7 +28,7 @@ func init() {
 	Cmd.Flags().BoolVarP(&includeHeaders, "output-headers", "o", false, "Output request headers")
 	Cmd.Flags().BoolVarP(&includeMethod, "output-method", "m", false, "Output request method")
 	Cmd.Flags().BoolVarP(&includeUrl, "output-url", "u", false, "Output request URL")
-	Cmd.Flags().StringVarP(&bodyFn, "body", "b", "", "Filename to read the response body from. Use - for stdin.")
+	Cmd.Flags().StringVarP(&bodyFn, "body", "b", "", "Filename to read the response body from. Use - or omit for stdin")
 	Cmd.Flags().StringVarP(&address, "address", "a", "", "Address to listen on")
 	Cmd.Flags().IntVarP(&port, "port", "p", 8000, "Port to listen on")
 	Cmd.Flags().IntVarP(&status, "status", "s", 200, "Status code to respond with")
@@ -57,18 +55,12 @@ var Cmd = &cobra.Command{
 		listener, err := net.Listen("tcp", address)
 		cobra.CheckErr(err)
 
-		if bodyFn != "" {
-			if bodyFn == "" {
-				if termutil.Isatty(os.Stdin.Fd()) {
-					cobra.CheckErr(errors.New("Unable to read from stdin"))
-				} else {
-					handler.data = os.Stdin
-				}
-			} else {
-				var err error
-				handler.data, err = os.Open(bodyFn)
-				cobra.CheckErr(err)
-			}
+		if bodyFn == "" {
+			handler.data, err = internal.StdinOrNothing()
+			cobra.CheckErr(err)
+		} else {
+			handler.data, err = internal.FileOrStdin(bodyFn)
+			cobra.CheckErr(err)
 		}
 
 		server := &http.Server{Addr: address, Handler: handler}
@@ -96,7 +88,7 @@ type responder struct {
 	includeMethod   bool
 	includeUrl      bool
 	headersIncluded bool
-	data            io.ReadSeeker
+	data            io.Reader
 }
 
 func (h responder) ServeHTTP(w http.ResponseWriter, req *http.Request) {

internal/io.go

@@ -0,0 +1,38 @@
+package internal
+
+import (
+	"errors"
+	"io"
+	"os"
+
+	"github.com/andrew-d/go-termutil"
+)
+
+func StdinOrNothing() (io.Reader, error) {
+	if termutil.Isatty(os.Stdin.Fd()) {
+		return nil, nil
+	}
+
+	return os.Stdin, nil
+}
+
+func FileOrStdin(args ...string) (io.Reader, error) {
+	if len(args) == 0 || args[0] == "-" {
+		if termutil.Isatty(os.Stdin.Fd()) {
+			return nil, errors.New("Unable to read from stdin")
+		}
+
+		return os.Stdin, nil
+	}
+
+	return os.Open(args[0])
+}
+
+func ReadFileOrStdin(args ...string) ([]byte, error) {
+	reader, err := FileOrStdin(args...)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	return io.ReadAll(reader)
+}