Change to shlex, added dependency and 'stream' template

cli/filter_data_through_cmd.go

@@ -2,92 +2,28 @@ package cli
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
+	"github.com/google/shlex"
 	"os/exec"
 	"strings"
 )
 
-func filterDataThroughCmd(data []byte, filter string, subject string) ([]byte, error) {
-	parts, err := parseCommandLine(filter)
+func filterDataThroughCmd(data []byte, filter string, subject, stream string) ([]byte, error) {
+	parts, err := shlex.Split(filter)
 	if err != nil {
 		return nil, fmt.Errorf("the filter command line could not be parsed: %w", err)
 	}
 	cmd := parts[0]
 	args := parts[1:]
 	// maybe we want to replace some strings to give the filter something to reason about?
-	for idx, arg := range args {
-		args[idx] = strings.ReplaceAll(arg, "{{subject}}", subject)
+	for idx := range args {
+		arg := &args[idx]
+		*arg = strings.ReplaceAll(*arg, "{{subject}}", subject)
+		*arg = strings.ReplaceAll(*arg, "{{stream}}", stream)
 	}
 	runner := exec.Command(cmd, args...)
 	// pass the message as string to stdin
 	runner.Stdin = bytes.NewReader(data)
 	// maybe we want to do something on error?
 	return runner.CombinedOutput()
 }
-
-func parseCommandLine(command string) ([]string, error) {
-	// copied from https://stackoverflow.com/questions/34118732/parse-a-command-line-string-into-flags-and-arguments-in-golang
-	// could be optimized but I think it is good enough for this use case
-	var args []string
-	state := "start"
-	current := ""
-	quote := "\""
-	escapeNext := true
-	for _, c := range command {
-
-		if state == "quotes" {
-			if string(c) != quote {
-				current += string(c)
-			} else {
-				args = append(args, current)
-				current = ""
-				state = "start"
-			}
-			continue
-		}
-
-		if escapeNext {
-			current += string(c)
-			escapeNext = false
-			continue
-		}
-
-		if c == '\\' {
-			escapeNext = true
-			continue
-		}
-
-		if c == '"' || c == '\'' {
-			state = "quotes"
-			quote = string(c)
-			continue
-		}
-
-		if state == "arg" {
-			if c == ' ' || c == '\t' {
-				args = append(args, current)
-				current = ""
-				state = "start"
-			} else {
-				current += string(c)
-			}
-			continue
-		}
-
-		if c != ' ' && c != '\t' {
-			state = "arg"
-			current += string(c)
-		}
-	}
-
-	if state == "quotes" {
-		return []string{}, errors.New(fmt.Sprintf("Unclosed quote in command line: %s", command))
-	}
-
-	if current != "" {
-		args = append(args, current)
-	}
-
-	return args, nil
-}

cli/stream_command.go

@@ -709,7 +709,7 @@ func (c *streamCmd) viewAction(_ *fisk.ParseContext) error {
 				data := msg.Data
 				var errFilter error
 				if c.vwTranslate != "" {
-					data, errFilter = filterDataThroughCmd(data, c.vwTranslate, msg.Subject)
+					data, errFilter = filterDataThroughCmd(data, c.vwTranslate, msg.Subject, meta.Stream())
 				}
 				if errFilter != nil {
 					fmt.Printf("%s\nError: %s\n\n", data, errFilter.Error())
@@ -2719,7 +2719,7 @@ func (c *streamCmd) getAction(_ *fisk.ParseContext) (err error) {
 	data := item.Data
 	var errFilter error
 	if c.vwTranslate != "" {
-		data, errFilter = filterDataThroughCmd(data, c.vwTranslate, item.Subject)
+		data, errFilter = filterDataThroughCmd(data, c.vwTranslate, item.Subject, c.stream)
 	}
 	if errFilter != nil {
 		fmt.Printf("%s\nError: %s\n\n", data, errFilter.Error())

cli/sub_command.go

@@ -461,7 +461,7 @@ func prettyPrintMsg(msg *nats.Msg, headersOnly bool, filter string) {
 		data := msg.Data
 		if filter != "" {
 			var err error
-			data, err = filterDataThroughCmd(msg.Data, filter, msg.Subject)
+			data, err = filterDataThroughCmd(msg.Data, filter, msg.Subject, "")
 			if err != nil {
 				fmt.Printf("%s\nError: %s\n\n", data, err.Error())
 				return

dependencies.md

@@ -26,6 +26,7 @@ This file lists the dependencies used in this repository.
 | github.com/nats-io/nats.go | Apache License 2.0 |
 | github.com/nats-io/nkeys | Apache License 2.0 |
 | github.com/nats-io/nuid | Apache License 2.0 |
+| github.com/google/shlex | Apache License 2.0 |
 | github.com/tylertreat/hdrhistogram-writer | Apache License 2.0 |
 | github.com/xeipuuv/gojsonpointer | Apache License 2.0 |
 | github.com/xeipuuv/gojsonreference | Apache License 2.0 |

go.mod

@@ -35,6 +35,7 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
 	github.com/gosuri/uilive v0.0.4 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect

go.sum

@@ -41,6 +41,8 @@ github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/gosuri/uilive v0.0.4 h1:hUEBpQDj8D8jXgtCdBu7sWsy5sbW/5GhuO8KBwJ2jyY=
 github.com/gosuri/uilive v0.0.4/go.mod h1:V/epo5LjjlDE5RJUcqx8dbw+zc93y5Ya3yg8tfZ74VI=
 github.com/gosuri/uiprogress v0.0.1 h1:0kpv/XY/qTmFWl/SkaJykZXrBBzwwadmW8fRb7RJSxw=