Merge branch 'commands' of github.com:mntn-xyz/amfora into commands

CHANGELOG.md

@@ -4,6 +4,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Added
+- Syntax highlighting for preformatted text blocks with alt text (#252, #263, [wiki page](https://github.com/makeworld-the-better-one/amfora/wiki/Source-Code-Highlighting))
+
+### Changed
+- Center text automatically, removing `left_margin` from the config (#233)
+- `max_width` defaults to 80 columns instead of 100 (#233)
+
+### Fixed
+- Modal can't be closed when opening non-gemini text URLs from the commandline (#283, #284)
+- External programs started by Amfora remain as zombie processes (#219)
+- Prevent link lines (and other types) from being wider than the `max_width` setting (#280)
+
+
 ## [1.9.2] - 2021-12-10
 ### Fixed
 - Preformatted text color showing even when `color = false` (bug since v1.8.0 at least) (#278)

README.md

@@ -142,7 +142,8 @@ Features in *italics* are in the master branch, but not in the latest release.
   - So is subscribing to a page, to know when it changes
 - [x] Open non-text files in another application
   - [x] Ability to stream content instead of downloading it first
-- [x] Run custom commands using the current or selected URL as an argument
+- [x] *Highlighting of preformatted code blocks that list a language in the alt text*
+- [x] *Run custom commands using the current or selected URL as an argument*
 - [ ] Stream support
 - [ ] Table of contents for pages
 - [ ] Search in pages with <kbd>Ctrl-F</kbd>
@@ -163,6 +164,7 @@ Amfora ❤️ open source!
 - [progressbar](https://github.com/schollz/progressbar)
 - [go-humanize](https://github.com/dustin/go-humanize)
 - [gofeed](https://github.com/mmcdole/gofeed)
+- [chroma](https://github.com/alecthomas/chroma) for source code syntax highlighting
 - [clipboard](https://github.com/atotto/clipboard)
 - [termenv](https://github.com/muesli/termenv)
 

THANKS.md

@@ -25,3 +25,4 @@ Thank you to the following contributors, who have helped make Amfora great. FOSS
 * Michael McDonagh (@m-mcdonagh)
 * mooff (@awfulcooking)
 * Josias (@justjosias)
+* mntn (@mntn-xyz)

config/config.go

@@ -196,10 +196,11 @@ func Init() error {
 	viper.SetDefault("a-general.search", "gemini://geminispace.info/search")
 	viper.SetDefault("a-general.color", true)
 	viper.SetDefault("a-general.ansi", true)
+	viper.SetDefault("a-general.highlight_code", true)
+	viper.SetDefault("a-general.highlight_style", "monokai")
 	viper.SetDefault("a-general.bullets", true)
 	viper.SetDefault("a-general.show_link", false)
-	viper.SetDefault("a-general.left_margin", 0.15)
-	viper.SetDefault("a-general.max_width", 100)
+	viper.SetDefault("a-general.max_width", 80)
 	viper.SetDefault("a-general.downloads", "")
 	viper.SetDefault("a-general.temp_downloads", "")
 	viper.SetDefault("a-general.page_max_size", 2097152)

config/default.go

@@ -58,17 +58,20 @@ color = true
 # Whether ANSI color codes from the page content should be rendered
 ansi = true
 
+# Whether or not to support source code highlighting in preformatted blocks based on alt text
+highlight_code = true
+
+# Which highlighting style to use (see https://xyproto.github.io/splash/docs/)
+highlight_style = "monokai"
+
 # Whether to replace list asterisks with unicode bullets
 bullets = true
 
 # Whether to show link after link text
 show_link = false
 
-# A number from 0 to 1, indicating what percentage of the terminal width the left margin should take up.
-left_margin = 0.15
-
 # The max number of columns to wrap a page's text to. Preformatted blocks are not wrapped.
-max_width = 100
+max_width = 80
 
 # 'downloads' is the path to a downloads folder.
 # An empty value means the code will find the default downloads folder for your system.

default-config.toml

@@ -55,17 +55,20 @@ color = true
 # Whether ANSI color codes from the page content should be rendered
 ansi = true
 
+# Whether or not to support source code highlighting in preformatted blocks based on alt text
+highlight_code = true
+
+# Which highlighting style to use (see https://xyproto.github.io/splash/docs/)
+highlight_style = "monokai"
+
 # Whether to replace list asterisks with unicode bullets
 bullets = true
 
 # Whether to show link after link text
 show_link = false
 
-# A number from 0 to 1, indicating what percentage of the terminal width the left margin should take up.
-left_margin = 0.15
-
 # The max number of columns to wrap a page's text to. Preformatted blocks are not wrapped.
-max_width = 100
+max_width = 80
 
 # 'downloads' is the path to a downloads folder.
 # An empty value means the code will find the default downloads folder for your system.

display/display.go

@@ -15,6 +15,7 @@ import (
 	"github.com/makeworld-the-better-one/amfora/renderer"
 	"github.com/makeworld-the-better-one/amfora/structs"
 	"github.com/makeworld-the-better-one/go-gemini"
+	"github.com/muesli/termenv"
 	"github.com/spf13/viper"
 )
 
@@ -60,6 +61,18 @@ var App = cview.NewApplication()
 func Init(version, commit, builtBy string) {
 	aboutInit(version, commit, builtBy)
 
+	// Detect terminal colors for syntax highlighting
+	switch termenv.ColorProfile() {
+	case termenv.TrueColor:
+		renderer.TermColor = "terminal16m"
+	case termenv.ANSI256:
+		renderer.TermColor = "terminal256"
+	case termenv.ANSI:
+		renderer.TermColor = "terminal16"
+	case termenv.Ascii:
+		renderer.TermColor = ""
+	}
+
 	App.EnableMouse(false)
 	App.SetRoot(layout, true)
 	App.SetAfterResizeFunc(func(width int, height int) {
@@ -228,7 +241,7 @@ func Init(version, commit, builtBy string) {
 			}
 			if i <= len(tabs[tab].page.Links) && i > 0 {
 				// It's a valid link number
-				followLink(tabs[tab], tabs[tab].page.URL, tabs[tab].page.Links[i-1])
+				go followLink(tabs[tab], tabs[tab].page.URL, tabs[tab].page.Links[i-1])
 				return
 			}
 			// Invalid link number, don't do anything

display/download.go

@@ -191,6 +191,8 @@ func open(u string, resp *gemini.Response) {
 			Error("File Opening Error", "Error executing custom command: "+err.Error())
 			return
 		}
+		//nolint:errcheck
+		go proc.Wait() // Prevent zombies, see #219
 		Info("Opened with " + cmd[0])
 		return
 	}
@@ -214,11 +216,14 @@ func open(u string, resp *gemini.Response) {
 		Info("Opened in default system viewer")
 	} else {
 		cmd := mediaHandler.Cmd
-		err := exec.Command(cmd[0], append(cmd[1:], path)...).Start()
+		proc := exec.Command(cmd[0], append(cmd[1:], path)...)
+		err := proc.Start()
 		if err != nil {
 			Error("File Opening Error", "Error executing custom command: "+err.Error())
 			return
 		}
+		//nolint:errcheck
+		go proc.Wait() // Prevent zombies, see #219
 		Info("Opened with " + cmd[0])
 	}
 	App.Draw()

display/handlers.go

@@ -48,16 +48,19 @@ func handleHTTP(u string, showInfo bool) bool {
 	}
 
 	// Custom command
-	var err error
+	var proc *exec.Cmd
 	if len(config.HTTPCommand) > 1 {
-		err = exec.Command(config.HTTPCommand[0], append(config.HTTPCommand[1:], u)...).Start()
+		proc = exec.Command(config.HTTPCommand[0], append(config.HTTPCommand[1:], u)...)
 	} else {
-		err = exec.Command(config.HTTPCommand[0], u).Start()
+		proc = exec.Command(config.HTTPCommand[0], u)
 	}
+	err := proc.Start()
 	if err != nil {
 		Error("HTTP Error", "Error executing custom browser command: "+err.Error())
 		return false
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	Info("Opened with: " + config.HTTPCommand[0])
 
 	App.Draw()
@@ -104,15 +107,18 @@ func handleOther(u string) {
 
 	// Custom application command
 
-	var err error
+	var proc *exec.Cmd
 	if len(handler) > 1 {
-		err = exec.Command(handler[0], append(handler[1:], u)...).Start()
+		proc = exec.Command(handler[0], append(handler[1:], u)...)
 	} else {
-		err = exec.Command(handler[0], u).Start()
+		proc = exec.Command(handler[0], u)
 	}
+	err := proc.Start()
 	if err != nil {
 		Error("URL Error", "Error executing custom command: "+err.Error())
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	Info("Opened with: " + handler[0])
 	App.Draw()
 }
@@ -352,7 +358,7 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 			// Disable read timeout and go back to start
 			res.SetReadTimeout(0) //nolint: errcheck
 			res.Body.(*rr.RestartReader).Restart()
-			go dlChoice("That page is too large. What would you like to do?", u, res)
+			dlChoice("That page is too large. What would you like to do?", u, res)
 			return ret("", false)
 		}
 		if errors.Is(err, renderer.ErrTimedOut) {
@@ -360,7 +366,7 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 			// Disable read timeout and go back to start
 			res.SetReadTimeout(0) //nolint: errcheck
 			res.Body.(*rr.RestartReader).Restart()
-			go dlChoice("Loading that page timed out. What would you like to do?", u, res)
+			dlChoice("Loading that page timed out. What would you like to do?", u, res)
 			return ret("", false)
 		}
 		if err != nil {
@@ -493,7 +499,7 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 				// Disable read timeout and go back to start
 				res.SetReadTimeout(0) //nolint: errcheck
 				res.Body.(*rr.RestartReader).Restart()
-				go dlChoice("That file could not be displayed. What would you like to do?", u, res)
+				dlChoice("That file could not be displayed. What would you like to do?", u, res)
 			}
 		}()
 		return ret("", false)
@@ -503,6 +509,6 @@ func handleURL(t *tab, u string, numRedirects int) (string, bool) {
 	// Disable read timeout and go back to start
 	res.SetReadTimeout(0) //nolint: errcheck
 	res.Body.(*rr.RestartReader).Restart()
-	go dlChoice("That file could not be displayed. What would you like to do?", u, res)
+	dlChoice("That file could not be displayed. What would you like to do?", u, res)
 	return ret("", false)
 }

display/modals.go

@@ -16,24 +16,21 @@ import (
 // The bookmark modal is in bookmarks.go
 
 var infoModal = cview.NewModal()
-
 var errorModal = cview.NewModal()
-var errorModalDone = make(chan struct{})
-
 var inputModal = cview.NewModal()
-var inputCh = make(chan string)
-var inputModalText string // The current text of the input field in the modal
-
 var yesNoModal = cview.NewModal()
 
-// Channel to receive yesNo answer on
+var inputCh = make(chan string)
 var yesNoCh = make(chan bool)
 
+var inputModalText string // The current text of the input field in the modal
+
+// Internal channel used to know when a modal has been dismissed
+var modalDone = make(chan struct{})
+
 func modalInit() {
 	infoModal.AddButtons([]string{"Ok"})
-
 	errorModal.AddButtons([]string{"Ok"})
-
 	yesNoModal.AddButtons([]string{"Yes", "No"})
 
 	panels.AddPanel(PanelInfoModal, infoModal, false, false)
@@ -145,6 +142,7 @@ func modalInit() {
 		panels.HidePanel(PanelInfoModal)
 		App.SetFocus(tabs[curTab].view)
 		App.Draw()
+		modalDone <- struct{}{}
 	})
 
 	errorModal.SetBorder(true)
@@ -153,7 +151,7 @@ func modalInit() {
 		panels.HidePanel(PanelErrorModal)
 		App.SetFocus(tabs[curTab].view)
 		App.Draw()
-		errorModalDone <- struct{}{}
+		modalDone <- struct{}{}
 	})
 
 	inputModal.SetBorder(true)
@@ -183,7 +181,7 @@ func modalInit() {
 	dlInit()
 }
 
-// Error displays an error on the screen in a modal.
+// Error displays an error on the screen in a modal, and blocks until dismissed by the user.
 func Error(title, text string) {
 	if text == "" {
 		text = "No additional information."
@@ -203,19 +201,21 @@ func Error(title, text string) {
 	App.SetFocus(errorModal)
 	App.Draw()
 
-	<-errorModalDone
+	<-modalDone
 }
 
-// Info displays some info on the screen in a modal.
+// Info displays some info on the screen in a modal, and blocks until dismissed by the user.
 func Info(s string) {
 	infoModal.SetText(s)
 	panels.ShowPanel(PanelInfoModal)
 	panels.SendToFront(PanelInfoModal)
 	App.SetFocus(infoModal)
 	App.Draw()
+
+	<-modalDone
 }
 
-// Input pulls up a modal that asks for input, and returns the user's input.
+// Input pulls up a modal that asks for input, waits for that input, and returns it.
 // It returns an bool indicating if the user chose to send input or not.
 func Input(prompt string, sensitive bool) (string, bool) {
 	// Remove elements and re-add them - to clear input text and keep input in focus
@@ -257,7 +257,7 @@ func Input(prompt string, sensitive bool) (string, bool) {
 	return resp, true
 }
 
-// YesNo displays a modal asking a yes-or-no question.
+// YesNo displays a modal asking a yes-or-no question, waits for an answer, then returns it as a bool.
 func YesNo(prompt string) bool {
 	if viper.GetBool("a-general.color") {
 		m := yesNoModal
@@ -289,7 +289,7 @@ func YesNo(prompt string) bool {
 }
 
 // Tofu displays the TOFU warning modal.
-// It returns a bool indicating whether the user wants to continue.
+// It blocks then returns a bool indicating whether the user wants to continue.
 func Tofu(host string, expiry time.Time) bool {
 	// Reuses yesNoModal, with error color
 

display/private.go

@@ -1,5 +1,8 @@
 package display
 
+// This file contains the functions that aren't part of the public API.
+// The funcs are for network and displaying.
+
 import (
 	"net/url"
 	"strconv"
@@ -9,17 +12,20 @@ import (
 	"github.com/makeworld-the-better-one/amfora/structs"
 )
 
-// This file contains the functions that aren't part of the public API.
-// The funcs are for network and displaying.
-
-// followLink should be used when the user "clicks" a link on a page.
-// Not when a URL is opened on a new tab for the first time.
-// It will handle setting the bottomBar.
+// followLink should be used when the user "clicks" a link on a page,
+// but not when a URL is opened on a new tab for the first time.
+//
+// It will handle updating the bottomBar.
+//
+// It should be called with the `go` keyword to spawn a new goroutine if
+// it would otherwise block the UI loop, such as when called from an input
+// handler.
+//
+// It blocks until navigation is finished, and we've completed any user
+// interaction related to loading the URL (such as info, error modals)
 func followLink(t *tab, prev, next string) {
 	if strings.HasPrefix(next, "about:") {
-		if final, ok := handleAbout(t, next); ok {
-			t.addToHistory(final)
-		}
+		goURL(t, next)
 		return
 	}
 
@@ -29,7 +35,7 @@ func followLink(t *tab, prev, next string) {
 			Error("URL Error", err.Error())
 			return
 		}
-		go goURL(t, nextURL)
+		goURL(t, nextURL)
 		return
 	}
 	// No content on current tab, so the "prev" URL is not valid.
@@ -39,7 +45,7 @@ func followLink(t *tab, prev, next string) {
 		Error("URL Error", "Link URL could not be parsed")
 		return
 	}
-	go goURL(t, next)
+	goURL(t, next)
 }
 
 // reformatPage will take the raw page content and reformat it according to the current terminal dimensions.

display/tab.go

@@ -86,7 +86,7 @@ func makeNewTab() *tab {
 			linkN, _ := strconv.Atoi(currentSelection[0])
 			tabs[tab].page.Selected = tabs[tab].page.Links[linkN]
 			tabs[tab].page.SelectedID = currentSelection[0]
-			followLink(tabs[tab], tabs[tab].page.URL, tabs[tab].page.Links[linkN])
+			go followLink(tabs[tab], tabs[tab].page.URL, tabs[tab].page.Links[linkN])
 			return
 		}
 		if len(currentSelection) == 0 && (key == tcell.KeyEnter || key == tcell.KeyTab) {
@@ -156,12 +156,12 @@ func makeNewTab() *tab {
 			if t.hasContent() {
 				savePath, err := downloadPage(t.page)
 				if err != nil {
-					Error("Download Error", fmt.Sprintf("Error saving page content: %v", err))
+					go Error("Download Error", fmt.Sprintf("Error saving page content: %v", err))
 				} else {
-					Info(fmt.Sprintf("Page content saved to %s. ", savePath))
+					go Info(fmt.Sprintf("Page content saved to %s. ", savePath))
 				}
 			} else {
-				Info("The current page has no content, so it couldn't be downloaded.")
+				go Info("The current page has no content, so it couldn't be downloaded.")
 			}
 			return nil
 		case config.CmdBack:
@@ -178,7 +178,7 @@ func makeNewTab() *tab {
 			currentURL := tabs[curTab].page.URL
 			err := clipboard.WriteAll(currentURL)
 			if err != nil {
-				Error("Copy Error", err.Error())
+				go Error("Copy Error", err.Error())
 				return nil
 			}
 			return nil
@@ -193,14 +193,14 @@ func makeNewTab() *tab {
 			if err != nil {
 				err := clipboard.WriteAll(selectedURL)
 				if err != nil {
-					Error("Copy Error", err.Error())
+					go Error("Copy Error", err.Error())
 					return nil
 				}
 				return nil
 			}
 			err = clipboard.WriteAll(copiedURL.String())
 			if err != nil {
-				Error("Copy Error", err.Error())
+				go Error("Copy Error", err.Error())
 				return nil
 			}
 			return nil
@@ -209,7 +209,7 @@ func makeNewTab() *tab {
 		if cmd >= config.CmdLink1 && cmd <= config.CmdLink0 {
 			if int(cmd) <= len(t.page.Links) {
 				// It's a valid link number
-				followLink(&t, t.page.URL, t.page.Links[cmd-1])
+				go followLink(&t, t.page.URL, t.page.Links[cmd-1])
 				return nil
 			}
 		}

display/thanks.go

@@ -29,4 +29,5 @@ Thank you to the following contributors, who have helped make Amfora great. FOSS
 * Michael McDonagh (@m-mcdonagh)
 * mooff (@awfulcooking)
 * Josias (@justjosias)
+* mntn (@mntn-xyz)
 `)

display/util.go

@@ -63,7 +63,14 @@ func isValidTab(t *tab) bool {
 }
 
 func leftMargin() int {
-	return int(float64(termW) * viper.GetFloat64("a-general.left_margin"))
+	// Return the left margin size that centers the text, assuming it's the max width
+	// https://github.com/makeworld-the-better-one/amfora/issues/233
+
+	lm := (termW - viper.GetInt("a-general.max_width")) / 2
+	if lm < 0 {
+		return 0
+	}
+	return lm
 }
 
 func textWidth() int {
@@ -73,13 +80,11 @@ func textWidth() int {
 		return viper.GetInt("a-general.max_width")
 	}
 
-	rightMargin := leftMargin()
-	if leftMargin() > 10 {
-		// 10 is the max right margin
-		rightMargin = 10
-	}
+	// Subtract left and right margin from total width to get text width
+	// Left and right margin are equal because text is automatically centered, see:
+	// https://github.com/makeworld-the-better-one/amfora/issues/233
 
-	max := termW - leftMargin() - rightMargin
+	max := termW - leftMargin()*2
 	if max < viper.GetInt("a-general.max_width") {
 		return max
 	}

go.mod

@@ -4,6 +4,7 @@ go 1.15
 
 require (
 	code.rocketnine.space/tslocum/cview v1.5.6-0.20210530175404-7e8817f20bdc
+	github.com/alecthomas/chroma v0.9.2
 	github.com/atotto/clipboard v0.1.4
 	github.com/dustin/go-humanize v1.0.0
 	github.com/fsnotify/fsnotify v1.4.9 // indirect

go.sum

@@ -21,6 +21,15 @@ github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/PuerkitoBio/goquery v1.5.1 h1:PSPBGne8NIUWw+/7vFBV+kG2J/5MOjbzc7154OaKCSE=
 github.com/PuerkitoBio/goquery v1.5.1/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc=
+github.com/alecthomas/assert v0.0.0-20170929043011-405dbfeb8e38 h1:smF2tmSOzy2Mm+0dGI2AIUHY+w0BUc+4tn40djz7+6U=
+github.com/alecthomas/assert v0.0.0-20170929043011-405dbfeb8e38/go.mod h1:r7bzyVFMNntcxPZXK3/+KdruV1H5KSlyVY0gc+NgInI=
+github.com/alecthomas/chroma v0.9.2 h1:yU1sE2+TZbLIQPMk30SolL2Hn53SR/Pv750f7qZ/XMs=
+github.com/alecthomas/chroma v0.9.2/go.mod h1:eMuEnpA18XbG/WhOWtCzJHS7WqEtDAI+HxdwoW0nVSk=
+github.com/alecthomas/colour v0.0.0-20160524082231-60882d9e2721 h1:JHZL0hZKJ1VENNfmXvHbgYlbUOvpzYzvy2aZU5gXVeo=
+github.com/alecthomas/colour v0.0.0-20160524082231-60882d9e2721/go.mod h1:QO9JBoKquHd+jz9nshCh40fOfO+JzsoXy8qTHF68zU0=
+github.com/alecthomas/kong v0.2.4/go.mod h1:kQOmtJgV+Lb4aj+I2LEn40cbtawdWJ9Y8QLq+lElKxE=
+github.com/alecthomas/repr v0.0.0-20180818092828-117648cd9897 h1:p9Sln00KOTlrYkxI1zYWl1QLnEqAqEARBEYa8FQnQcY=
+github.com/alecthomas/repr v0.0.0-20180818092828-117648cd9897/go.mod h1:xTS7Pm1pD1mvyM075QCDSRqH6qRLXylzS24ZTpRiSzQ=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/andybalholm/cascadia v1.1.0 h1:BuuO6sSfQNFRu1LppgbD25Hr2vLYW25JvxHs5zzsLTo=
@@ -42,11 +51,15 @@ github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3Ee
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964 h1:y5HC9v93H5EPKqaS1UYVg1uYah5Xf51mBfIoWehClUQ=
+github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964/go.mod h1:Xd9hchkHSWYkEqJwUGisez3G1QY8Ryz0sdWrLPMGjLk=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
+github.com/dlclark/regexp2 v1.4.0 h1:F1rxgk7p4uKjwIQxBs9oAXe5CqrXlCduYEJvrF4u93E=
+github.com/dlclark/regexp2 v1.4.0/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
 github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
@@ -141,7 +154,9 @@ github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czP
 github.com/makeworld-the-better-one/go-gemini v0.12.1 h1:cWHvCHL31Caq3Rm9elCFFoQeyrn92Kv7KummsVxCOFg=
 github.com/makeworld-the-better-one/go-gemini v0.12.1/go.mod h1:F+3x+R1xeYK90jMtBq+U+8Sh64r2dHleDZ/en3YgSmg=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
+github.com/mattn/go-colorable v0.1.6/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-isatty v0.0.13 h1:qdl+GuBjcsKKDco5BsxPJlId98mSWNKqYA+Co0SC1yA=
 github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
@@ -183,6 +198,7 @@ github.com/pelletier/go-toml v1.8.0 h1:Keo9qb7iRJs2voHvunFtuuYFsbWeOBh8/P9v/kVMF
 github.com/pelletier/go-toml v1.8.0/go.mod h1:D6yutnOGMveHEPV7VQOuvI/gXY61bv+9bAOTRnLElKs=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
@@ -207,6 +223,8 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
 github.com/schollz/progressbar/v3 v3.8.0 h1:BKyefEMgFBDbo+JaeqHcm/9QdSj8qG8sUY+6UppGpnw=
 github.com/schollz/progressbar/v3 v3.8.0/go.mod h1:Y9mmL2knZj3LUaBDyBEzFdPrymIr08hnlFMZmfxwbx4=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
+github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
+github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
@@ -314,6 +332,8 @@ golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200413165638-669c56c373c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210223095934-7937bea0104d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210309040221-94ec62e08169/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

renderer/renderer.go

@@ -5,6 +5,7 @@
 package renderer
 
 import (
+	"bytes"
 	"fmt"
 	urlPkg "net/url"
 	"regexp"
@@ -12,13 +13,25 @@ import (
 	"strings"
 
 	"code.rocketnine.space/tslocum/cview"
+	"github.com/alecthomas/chroma/formatters"
+	"github.com/alecthomas/chroma/lexers"
+	"github.com/alecthomas/chroma/styles"
 	"github.com/makeworld-the-better-one/amfora/config"
 	"github.com/spf13/viper"
 )
 
+// Terminal color information, set during display initialization by display/display.go
+var TermColor string
+
 // Regex for identifying ANSI color codes
 var ansiRegex = regexp.MustCompile(`\x1b\[[0-9;]*m`)
 
+// Regex for identifying possible language string, based on RFC 6838 and lexers used by Chroma
+var langRegex = regexp.MustCompile(`^([a-zA-Z0-9]+/)?[a-zA-Z0-9]+([a-zA-Z0-9!_\#\$\&\-\^\.\+]+)*`)
+
+// Regex for removing trailing newline (without disturbing ANSI codes) from code formatted with Chroma
+var trailingNewline = regexp.MustCompile(`(\r?\n)(?:\x1b\[[0-9;]*m)*$`)
+
 // RenderANSI renders plain text pages containing ANSI codes.
 // Practically, it is used for the text/x-ansi.
 func RenderANSI(s string) string {
@@ -45,6 +58,10 @@ func RenderPlainText(s string) string {
 //
 // Set includeFirst to true if the prefix and suffix should be applied to the first wrapped line as well
 func wrapLine(line string, width int, prefix, suffix string, includeFirst bool) []string {
+	if width < 1 {
+		width = 1
+	}
+
 	// Anonymous function to allow recovery from potential WordWrap panic
 	var ret []string
 	func() {
@@ -183,7 +200,7 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 					// Add the link text in blue (in a region), and a gray link number to the left of it
 					// Those are the default colors, anyway
 
-					wrappedLink = wrapLine(linkText, width,
+					wrappedLink = wrapLine(linkText, width-indent,
 						strings.Repeat(" ", indent)+
 							`["`+strconv.Itoa(num-1)+`"][`+config.GetColorString("amfora_link")+`]`,
 						`[-][""]`,
@@ -198,8 +215,8 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 				} else {
 					// No color
 
-					wrappedLink = wrapLine(linkText, width,
-						strings.Repeat(" ", len(strconv.Itoa(num))+4)+ // +4 for spaces and brackets
+					wrappedLink = wrapLine(linkText, width-indent,
+						strings.Repeat(" ", indent)+ // +4 for spaces and brackets
 							`["`+strconv.Itoa(num-1)+`"]`,
 						`[""]`,
 						false, // Don't indent the first line, it's the one with link number
@@ -215,7 +232,7 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 				if viper.GetBool("a-general.color") {
 					// Color
 
-					wrappedLink = wrapLine(linkText, width,
+					wrappedLink = wrapLine(linkText, width-indent,
 						strings.Repeat(" ", indent)+
 							`["`+strconv.Itoa(num-1)+`"]`+linkTag,
 						`[-::-][""]`,
@@ -229,7 +246,7 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 				} else {
 					// No color
 
-					wrappedLink = wrapLine(linkText, width,
+					wrappedLink = wrapLine(linkText, width-indent,
 						strings.Repeat(" ", indent)+
 							`["`+strconv.Itoa(num-1)+`"]`,
 						`[::-][""]`,
@@ -248,7 +265,8 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 		} else if strings.HasPrefix(lines[i], "* ") {
 			if viper.GetBool("a-general.bullets") {
 				// Wrap list item, and indent wrapped lines past the bullet
-				wrappedItem := wrapLine(lines[i][1:], width,
+				wrappedItem := wrapLine(lines[i][1:],
+					width-4, // Subtract the 4 indent spaces
 					fmt.Sprintf("    [%s]", config.GetColorString("list_text")),
 					"[-]", false)
 				// Add bullet
@@ -256,7 +274,8 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 					wrappedItem[0] + "[-]"
 				wrappedLines = append(wrappedLines, wrappedItem...)
 			} else {
-				wrappedItem := wrapLine(lines[i][1:], width,
+				wrappedItem := wrapLine(lines[i][1:],
+					width-4, // Subtract the 4 indent spaces
 					fmt.Sprintf("    [%s]", config.GetColorString("list_text")),
 					"[-]", false)
 				// Add "*"
@@ -277,7 +296,9 @@ func convertRegularGemini(s string, numLinks, width int, proxied bool) (string,
 				lines[i] = strings.TrimPrefix(lines[i], ">")
 				lines[i] = strings.TrimPrefix(lines[i], " ")
 				wrappedLines = append(wrappedLines,
-					wrapLine(lines[i], width, fmt.Sprintf("[%s::i]> ", config.GetColorString("quote_text")),
+					wrapLine(lines[i],
+						width-2, // Subtract 2 for width of prefix string
+						fmt.Sprintf("[%s::i]> ", config.GetColorString("quote_text")),
 						"[-::-]", true)...,
 				)
 			}
@@ -315,11 +336,46 @@ func RenderGemini(s string, width int, proxied bool) (string, []string) {
 	pre := false
 	buf := "" // Block of regular or preformatted lines
 
+	// Language, formatter, and style for syntax highlighting
+	lang := ""
+	formatterName := TermColor
+	styleName := viper.GetString("a-general.highlight_style")
+
 	// processPre is for rendering preformatted blocks
 	processPre := func() {
 
+		syntaxHighlighted := false
+
+		// Perform syntax highlighting if language is set
+		if lang != "" {
+			style := styles.Get(styleName)
+			if style == nil {
+				style = styles.Fallback
+			}
+			formatter := formatters.Get(formatterName)
+			if formatter == nil {
+				formatter = formatters.Fallback
+			}
+			lexer := lexers.Get(lang)
+			if lexer == nil {
+				lexer = lexers.Fallback
+			}
+
+			// Tokenize and format the text after stripping ANSI codes, replacing buffer if there are no errors
+			iterator, err := lexer.Tokenise(nil, ansiRegex.ReplaceAllString(buf, ""))
+			if err == nil {
+				formattedBuffer := new(bytes.Buffer)
+				if formatter.Format(formattedBuffer, style, iterator) == nil {
+					// Strip extra newline added by Chroma and replace buffer
+					buf = string(trailingNewline.ReplaceAll(formattedBuffer.Bytes(), []byte{}))
+				}
+				syntaxHighlighted = true
+			}
+		}
+
 		// Support ANSI color codes in preformatted blocks - see #59
-		if viper.GetBool("a-general.color") && viper.GetBool("a-general.ansi") {
+		// This will also execute if code highlighting was successful for this block
+		if viper.GetBool("a-general.color") && (viper.GetBool("a-general.ansi") || syntaxHighlighted) {
 			buf = cview.TranslateANSI(buf)
 			// The TranslateANSI function will reset the colors when it encounters
 			// an ANSI reset code, injecting a full reset tag: [-:-:-]
@@ -366,9 +422,21 @@ func RenderGemini(s string, width int, proxied bool) (string, []string) {
 				// Don't add the current line with backticks
 				processPre()
 
+				// Clear the language
+				lang = ""
 			} else {
 				// Not preformatted, regular text
 				processRegular()
+
+				if viper.GetBool("a-general.highlight_code") {
+					// Check for alt text indicating a language that Chroma can highlight
+					alt := strings.TrimSpace(strings.TrimPrefix(lines[i], "```"))
+					if matches := langRegex.FindStringSubmatch(alt); matches != nil {
+						if lexers.Get(matches[0]) != nil {
+							lang = matches[0]
+						}
+					}
+				}
 			}
 			buf = "" // Clear buffer for next block
 			pre = !pre

sysopen/open_browser_darwin.go

@@ -7,9 +7,12 @@ import "os/exec"
 
 // Open opens `path` in default system viewer.
 func Open(path string) (string, error) {
-	err := exec.Command("open", path).Start()
+	proc := exec.Command("open", path)
+	err := proc.Start()
 	if err != nil {
 		return "", err
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	return "Opened in default system viewer", nil
 }

sysopen/open_browser_unix.go

@@ -25,9 +25,12 @@ func Open(path string) (string, error) {
 	case xdgOpenNotFoundErr == nil:
 		// Use start rather than run or output in order
 		// to make application run in background.
-		if err := exec.Command(xdgOpenPath, path).Start(); err != nil {
+		proc := exec.Command(xdgOpenPath, path)
+		if err := proc.Start(); err != nil {
 			return "", err
 		}
+		//nolint:errcheck
+		go proc.Wait() // Prevent zombies, see #219
 		return "Opened in default system viewer", nil
 	default:
 		return "", fmt.Errorf("could not determine default system viewer. " +

sysopen/open_browser_windows.go

@@ -8,9 +8,12 @@ import "os/exec"
 
 // Open opens `path` in default system vierwer.
 func Open(path string) (string, error) {
-	err := exec.Command("rundll32", "url.dll,FileProtocolHandler", path).Start()
+	proc := exec.Command("rundll32", "url.dll,FileProtocolHandler", path)
+	err := proc.Start()
 	if err != nil {
 		return "", err
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	return "Opened in default system viewer", nil
 }

webbrowser/open_browser_darwin.go

@@ -7,9 +7,12 @@ import "os/exec"
 
 // Open opens `url` in default system browser.
 func Open(url string) (string, error) {
-	err := exec.Command("open", url).Start()
+	proc := exec.Command("open", url)
+	err := proc.Start()
 	if err != nil {
 		return "", err
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	return "Opened in system default web browser", nil
 }

webbrowser/open_browser_unix.go

@@ -34,14 +34,20 @@ func Open(url string) (string, error) {
 	case xdgOpenNotFoundErr == nil: // Prefer xdg-open over $BROWSER
 		// Use start rather than run or output in order
 		// to make browser running in background.
-		if err := exec.Command(xdgOpenPath, url).Start(); err != nil {
+		proc := exec.Command(xdgOpenPath, url)
+		if err := proc.Start(); err != nil {
 			return "", err
 		}
+		//nolint:errcheck
+		go proc.Wait() // Prevent zombies, see #219
 		return "Opened in system default web browser", nil
 	case envBrowser != "":
-		if err := exec.Command(envBrowser, url).Start(); err != nil {
+		proc := exec.Command(envBrowser, url)
+		if err := proc.Start(); err != nil {
 			return "", err
 		}
+		//nolint:errcheck
+		go proc.Wait() // Prevent zombies, see #219
 		return "Opened in system default web browser", nil
 	default:
 		return "", fmt.Errorf("could not determine system browser")

webbrowser/open_browser_windows.go

@@ -8,9 +8,12 @@ import "os/exec"
 
 // Open opens `url` in default system browser.
 func Open(url string) (string, error) {
-	err := exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
+	proc := exec.Command("rundll32", "url.dll,FileProtocolHandler", url)
+	err := proc.Start()
 	if err != nil {
 		return "", err
 	}
+	//nolint:errcheck
+	go proc.Wait() // Prevent zombies, see #219
 	return "Opened in system default web browser", nil
 }