refactor demon and selector into a single go binary

README.md

@@ -10,8 +10,8 @@ A basic clipboard manager for Wayland.
 
 ## Usage
 
-The demon that collects history is written in Go. Install it in your path, then run it in your Sway session by adding `exec clipman` at the beginning of your config.
+Install the binary in your path, then run it in your Sway session by adding `exec clipman -d` at the beginning of your config.
 
-You can configure how many history items to preserve (default: 15) by editing directly the source.
+You can configure how many unique history items to preserve (default: 15) by editing directly the source.
 
-To query the history and select items, run the provided python script (`clipman.py`). You can assign it to a keybinding.
+To query the history and select items, run the binary as `clipman -s`. You can assign it to a keybinding: `bindsym $mod+h exec clipman -s`.

clipman.py

@@ -1,45 +0,0 @@
-#!/usr/bin/python
-import json
-import os
-import subprocess
-import sys
-
-MAX = 15
-
-
-def selector(input_, max_):
-    """Send list to dmenu for selection. Display max items."""
-    cmd = [
-        "dmenu",
-        "-b",
-        "-fn",
-        "-misc-dejavu sans mono-medium-r-normal--17-120-100-100-m-0-iso8859-16",
-        "-l",
-        str(max_),
-    ]
-    chosen = (
-        subprocess.run(
-            cmd, input="\n".join(input_).encode("utf-8"), capture_output=True
-        )
-        .stdout.decode()
-        .strip()
-    )
-    return chosen
-
-
-def main():
-    try:
-        with open(os.path.expanduser("~/.local/share/clipman.json")) as f:
-            history = json.load(f)
-    except FileNotFoundError:
-        sys.exit("No history available")
-
-    history = [repr(x) for x in reversed(history)]  # don't expand newlines
-
-    selected = selector(history, MAX)
-
-    subprocess.run(["wl-copy", selected])
-
-
-if __name__ == "__main__":
-    main()

demon.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os/exec"
+	"time"
+)
+
+const sleep = 1 * time.Second
+
+func write(history []string, histfile string) error {
+	histlog, err := json.Marshal(history)
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(histfile, histlog, 0644)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func filter(history []string, text string) []string {
+	var (
+		found bool
+		idx   int
+	)
+
+	for i, el := range history {
+		if el == text {
+			found = true
+			idx = i
+			break
+		}
+	}
+
+	if found {
+		// we know that idx can't be the last element, because
+		// we never get to call this function if that's the case
+		history = append(history[:idx], history[idx+1:]...)
+	}
+
+	return history
+}
+
+func listen(history []string, histfile string) error {
+
+	for {
+
+		t, err := exec.Command("wl-paste", []string{"-n", "-t", "text"}...).Output()
+		text := string(t)
+		if err != nil || text == "" {
+			// there's nothing to select, so we sleep.
+			time.Sleep(sleep)
+			continue
+		}
+
+		l := len(history)
+
+		if l > 0 {
+
+			// wl-paste will always give back the last copied text
+			// (as long as the place we copied from is still running)
+			if history[l-1] == text {
+				time.Sleep(sleep)
+				continue
+			}
+
+			if l == max {
+				// we know that at any given time len(history) cannot be bigger than max,
+				// so it's enough to drop the first element
+				history = history[1:]
+			}
+
+			// remove duplicates
+			// consider doing this in the frontend, for sparing resources
+			history = filter(history, text)
+
+		}
+
+		history = append(history, text)
+
+		// dump history to file so that other apps can query it
+		err = write(history, histfile)
+		if err != nil {
+			return err
+		}
+
+		time.Sleep(sleep)
+	}
+
+}

go.mod

@@ -1,3 +1,9 @@
 module clipman
 
 go 1.12
+
+require (
+	github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc // indirect
+	github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf // indirect
+	gopkg.in/alecthomas/kingpin.v2 v2.2.6
+)

go.sum

@@ -0,0 +1,6 @@
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=

main.go

@@ -5,101 +5,51 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"os/exec"
 	"path"
-	"time"
+
+	"gopkg.in/alecthomas/kingpin.v2"
 )
 
 const max = 15
-const sleep = 1 * time.Second
 
-func write(history []string, histf string) error {
-	histlog, err := json.Marshal(history)
-	if err != nil {
-		return err
-	}
-	err = ioutil.WriteFile(histf, histlog, 0644)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func filter(history []string, text string) []string {
 var (
-		found bool
+	app        = kingpin.New("clipman", "A clipboard manager for Wayland")
-		idx   int
+	asDemon    = app.Flag("demon", "Run as a demon to record clipboard events").Short('d').Default("false").Bool()
+	asSelector = app.Flag("select", "Select an item from clipboard history").Short('s').Default("false").Bool()
 )
 
-	for i, el := range history {
+var (
-		if el == text {
+	histfile string
-			found = true
+	history  []string
-			idx = i
+)
-			break
-		}
-	}
-
-	if found {
-		// we know that idx can't be the last element, because
-		// we never get to call this function if that's the case
-		history = append(history[:idx], history[idx+1:]...)
-	}
-
-	return history
-}
 
 func main() {
+	app.HelpFlag.Short('h')
+	kingpin.MustParse(app.Parse(os.Args[1:]))
+	if (*asDemon && *asSelector) || (!*asDemon && !*asSelector) {
+		log.Fatal("Missing or incompatible options. See -h/--help for info")
+	}
+
 	h, err := os.UserHomeDir()
 	if err != nil {
 		log.Fatal(err)
 	}
-	histf := path.Join(h, ".local/share/clipman.json")
+	histfile = path.Join(h, ".local/share/clipman.json")
 
-	var history []string
+	b, err := ioutil.ReadFile(histfile)
-	b, err := ioutil.ReadFile(histf)
 	if err == nil {
 		if err := json.Unmarshal(b, &history); err != nil {
 			log.Fatal(err)
 		}
 	}
 
-	for {
+	if *asDemon {
-		t, err := exec.Command("wl-paste", []string{"-n", "-t", "text"}...).Output()
+		if err := listen(history, histfile); err != nil {
-		text := string(t)
+			log.Fatal(err)
-		if err != nil || text == "" {
+		}
-			// there's nothing to select, so we sleep.
+	} else if *asSelector {
-			time.Sleep(sleep)
+		if err := selector(history); err != nil {
-			continue
-		}
-
-		l := len(history)
-
-		if l > 0 {
-			// wl-paste will always give back the last copied text
-			// (as long as the place we copied from is still running)
-			if history[l-1] == text {
-				time.Sleep(sleep)
-				continue
-			}
-
-			if l == max {
-				// we know that at any given time len(history) cannot be bigger than max,
-				// so it's enough to drop the first element
-				history = history[1:]
-			}
-
-			// remove duplicates
-			history = filter(history, text)
-		}
-
-		history = append(history, text)
-
-		// dump history to file so that other apps can query it
-		err = write(history, histf)
-		if err != nil {
 			log.Fatal(err)
 		}
-
-		time.Sleep(sleep)
 	}
 }

selector.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+func selector(history []string) error {
+
+	// reverse the history
+	for i, j := 0, len(history)-1; i < j; i, j = i+1, j-1 {
+		history[i], history[j] = history[j], history[i]
+	}
+
+	selected, err := dmenu(history, max)
+	if err != nil {
+		// dmenu exits with error when no selection done
+		return nil
+	}
+
+	if err := exec.Command("wl-copy", selected).Run(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func dmenu(list []string, max int) (string, error) {
+	args := []string{"dmenu", "-b",
+		"-fn",
+		"-misc-dejavu sans mono-medium-r-normal--17-120-100-100-m-0-iso8859-16",
+		"-l",
+		strconv.Itoa(max)}
+
+	// dmenu will break if items contain newlines, so we must pass them as literals.
+	// however, when it sends them back, we need a way to restore them to non literals
+	guide := make(map[string]int)
+	reprList := []string{}
+	for i, l := range list {
+		repr := fmt.Sprintf("%#v", l)
+		guide[repr] = i
+		reprList = append(reprList, repr)
+	}
+
+	input := strings.NewReader(strings.Join(reprList, "\n"))
+
+	cmd := exec.Cmd{Path: "/usr/bin/dmenu", Args: args, Stdin: input}
+	selected, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+
+	unescaped := list[guide[string(selected)]]
+
+	return unescaped, nil
+}