TLDR client written in Go

Soon to be distributable as a static binary, through the Github Releases
API.

.gitignore

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+/tldr
+*.swp

README.md

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+
+A work-in-progress [Go](http://golang.org/) client for [tldr](https://github.com/rprieto/tldr/).
+
+# Setup
+
+If you have Go installed, grab the latest version:
+
+    go get github.com/pranavraja/tldr
+
+Binary releases for common platforms will be added soon, once I add a few more features.
+
+# Prerequisites
+
+If you installed using `go get`, make sure `$GOPATH/bin` is in your `$PATH`.
+
+# Usage
+
+    tldr <command>
+
+Fetch the docs for `command` and render them to the terminal.
+
+# Hacking
+
+Once you have cloned the repo, build using `go build`, run the tests using `go test`.
+
+# TODO (contributions welcome)
+
+- Improve rendering of command placeholders, like in `sed 's/a/b/' {{filename}}`
+- Caching of commands
+- Add a command-line flag to override the platform (currently only "common" is supported)
+- Improve multi-line command rendering

main.go

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+package main
+
+import (
+	"os"
+)
+
+func main() {
+	if len(os.Args) <= 1 {
+		println("Usage: tldr <command>")
+		os.Exit(1)
+	}
+	cmd := os.Args[1]
+	platform := "common"
+	page, err := GetPageForPlatform(cmd, platform)
+	if err != nil {
+		println(err.Error())
+		os.Exit(1)
+	}
+	println(Render(page))
+}

page.go

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+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+)
+
+var remote string = "http://raw.github.com/rprieto/tldr/master/pages"
+
+// Caller must close the response body after reading.
+func GetPageForPlatform(page, platform string) (io.ReadCloser, error) {
+	resp, err := http.Get(remote + "/" + platform + "/" + page + ".md")
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode == 404 {
+		return nil, fmt.Errorf("Not found.\nTo add this command, send Romain a pull request at:\n  https://github.com/rprieto/tldr")
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("Unexpected status code: %d", resp.StatusCode)
+	}
+	return resp.Body, nil
+}

page_test.go

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+package main
+
+import (
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+type testServer struct {
+	originalRequest *http.Request
+	statusCode      int
+	response        string
+}
+
+func (t *testServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	t.originalRequest = r
+	w.WriteHeader(t.statusCode)
+	io.WriteString(w, t.response)
+}
+
+func (t *testServer) Intercept(test func()) {
+	server := httptest.NewServer(t)
+	defer server.Close()
+	remote = server.URL
+	test()
+}
+
+func TestGetPageForPlatform_404(t *testing.T) {
+	server := testServer{statusCode: 404, response: "NOT FOUND BRO"}
+	var resp io.ReadCloser
+	var err error
+	server.Intercept(func() {
+		resp, err = GetPageForPlatform("tldr", "osx")
+	})
+	if resp != nil {
+		t.Errorf("Expected a nil response but got a non-nil response")
+	}
+	if err == nil {
+		t.Errorf("Expected an error for an invalid status code, but got none")
+	}
+}
+
+func TestGetPageForPlatform(t *testing.T) {
+	server := testServer{statusCode: 200, response: "DO IT BRO"}
+	var resp io.ReadCloser
+	var err error
+	server.Intercept(func() {
+		resp, err = GetPageForPlatform("tldr", "osx")
+	})
+	defer resp.Close()
+	if err != nil {
+		t.Error(err)
+	}
+	if expected := "/osx/tldr.md"; server.originalRequest.URL.Path != expected {
+		t.Errorf("Page requested from wrong url: %s", server.originalRequest.URL.Path)
+	}
+	if body, _ := ioutil.ReadAll(resp); string(body) != "DO IT BRO" {
+		t.Errorf("Read wrong body: %s")
+	}
+}

render.go

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+package main
+
+import (
+	"bufio"
+	"io"
+	"strings"
+)
+
+const (
+	TermEscapePrefix = "\033["
+	TermEscapeSuffix = "m"
+
+	Reset = TermEscapePrefix + "0" + TermEscapeSuffix
+
+	Bold = TermEscapePrefix + "1" + TermEscapeSuffix
+
+	Green = TermEscapePrefix + "32" + TermEscapeSuffix
+	Cyan  = TermEscapePrefix + "36" + TermEscapeSuffix
+	White = TermEscapePrefix + "37" + TermEscapeSuffix
+
+	OnBlue = TermEscapePrefix + "44" + TermEscapeSuffix
+	OnGrey = TermEscapePrefix + "40" + TermEscapeSuffix
+)
+
+// Render pretties up some markdown for terminal display.
+// Only a small subset of markdown is actually supported,
+// as described in https://github.com/rprieto/tldr/blob/master/CONTRIBUTING.md#markdown-format
+func Render(markdown io.Reader) (rendered string) {
+	scanner := bufio.NewScanner(markdown)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "#") {
+			// Heading
+			rendered += OnBlue + Bold + Cyan + strings.TrimLeft(line, "# ") + Reset + "\n"
+		} else if strings.HasPrefix(line, ">") {
+			// Quotation
+			rendered += "  " + White + strings.TrimLeft(line, "> ") + Reset + "\n"
+		} else if strings.HasPrefix(line, "-") {
+			// Inline list
+			rendered += Green + line + Reset + "\n"
+		} else if strings.HasPrefix(line, "`") {
+			// Code
+			rendered += "  " + OnGrey + White + strings.Trim(line, "`") + Reset + "\n"
+		} else {
+			rendered += line + "\n"
+		}
+	}
+	return rendered
+}

render_test.go

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+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRender(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{"simple string", "asd\nsdfghi\njk", "asd\nsdfghi\njk\n"},
+		{"simple utf8 string", "Hello, 世界\n\ni like chips", "Hello, 世界\n\ni like chips\n"},
+		{"headings", "# Hello, 世界\n\ni like chips", "\033[44m\033[1m\033[36mHello, 世界\033[0m\n\ni like chips\n"},
+		{"quotation", "Title\n> Raja", "Title\n  \033[37mRaja\033[0m\n"},
+		{"inline list", "Title\n- Raja\n- Pranav", "Title\n\033[32m- Raja\033[0m\n\033[32m- Pranav\033[0m\n"},
+		{"code", "Title\n`go build`\n`go test`", "Title\n  \033[40m\033[37mgo build\033[0m\n  \033[40m\033[37mgo test\033[0m\n"},
+	}
+	for _, test := range tests {
+		rendered := Render(strings.NewReader(test.input))
+		if rendered != test.expected {
+			t.Errorf("Incorrect render of %s: got '%s', want '%s'", test.name, rendered, test.expected)
+		}
+	}
+}