1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
// Copyright © 2013-14 Steve Francia <spf@spf13.com>.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package helpers
import (
"bytes"
"crypto/sha1"
"fmt"
"github.com/spf13/hugo/hugofs"
jww "github.com/spf13/jwalterweatherman"
"github.com/spf13/viper"
"io"
"io/ioutil"
"os/exec"
"path/filepath"
"sort"
"strings"
)
const pygmentsBin = "pygmentize"
// HasPygments checks to see if Pygments is installed and available
// on the system.
func HasPygments() bool {
if _, err := exec.LookPath(pygmentsBin); err != nil {
return false
}
return true
}
// Highlight takes some code and returns highlighted code.
func Highlight(code, lang, optsStr string) string {
if !HasPygments() {
jww.WARN.Println("Highlighting requires Pygments to be installed and in the path")
return code
}
options, err := parsePygmentsOpts(optsStr)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
// Try to read from cache first
hash := sha1.New()
io.WriteString(hash, code)
io.WriteString(hash, lang)
io.WriteString(hash, options)
fs := hugofs.OsFs
cacheDir := viper.GetString("CacheDir")
var cachefile string
if cacheDir != "" {
cachefile = filepath.Join(cacheDir, fmt.Sprintf("pygments-%x", hash.Sum(nil)))
exists, err := Exists(cachefile, fs)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
if exists {
f, err := fs.Open(cachefile)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
s, err := ioutil.ReadAll(f)
if err != nil {
jww.ERROR.Print(err.Error())
return code
}
return string(s)
}
}
// No cache file, render and cache it
var out bytes.Buffer
var stderr bytes.Buffer
var langOpt string
if lang == "" {
langOpt = "-g" // Try guessing the language
} else {
langOpt = "-l" + lang
}
cmd := exec.Command(pygmentsBin, langOpt, "-fhtml", "-O", options)
cmd.Stdin = strings.NewReader(code)
cmd.Stdout = &out
cmd.Stderr = &stderr
if err := cmd.Run(); err != nil {
jww.ERROR.Print(stderr.String())
return code
}
str := out.String()
// inject code tag into Pygments output
if lang != "" && strings.Contains(str, "<pre>") {
codeTag := fmt.Sprintf(`<pre><code class="language-%s" data-lang="%s">`, lang, lang)
str = strings.Replace(str, "<pre>", codeTag, 1)
str = strings.Replace(str, "</pre>", "</code></pre>", 1)
}
if cachefile != "" {
// Write cache file
if err := WriteToDisk(cachefile, strings.NewReader(str), fs); err != nil {
jww.ERROR.Print(stderr.String())
}
}
return str
}
var pygmentsKeywords = make(map[string]bool)
func init() {
pygmentsKeywords["style"] = true
pygmentsKeywords["encoding"] = true
pygmentsKeywords["noclasses"] = true
pygmentsKeywords["hl_lines"] = true
pygmentsKeywords["linenos"] = true
pygmentsKeywords["classprefix"] = true
pygmentsKeywords["startinline"] = true
}
func parseOptions(options map[string]string, in string) error {
in = strings.Trim(in, " ")
if in != "" {
for _, v := range strings.Split(in, ",") {
keyVal := strings.Split(v, "=")
key := strings.ToLower(strings.Trim(keyVal[0], " "))
if len(keyVal) != 2 || !pygmentsKeywords[key] {
return fmt.Errorf("invalid Pygments option: %s", key)
}
options[key] = keyVal[1]
}
}
return nil
}
func createOptionsString(options map[string]string) string {
var keys []string
for k := range options {
keys = append(keys, k)
}
sort.Strings(keys)
var optionsStr string
for i, k := range keys {
optionsStr += fmt.Sprintf("%s=%s", k, options[k])
if i < len(options)-1 {
optionsStr += ","
}
}
return optionsStr
}
func parseDefaultPygmentsOpts() (map[string]string, error) {
options := make(map[string]string)
err := parseOptions(options, viper.GetString("PygmentsOptions"))
if err != nil {
return nil, err
}
if viper.IsSet("PygmentsStyle") {
options["style"] = viper.GetString("PygmentsStyle")
}
if viper.IsSet("PygmentsUseClasses") {
if viper.GetBool("PygmentsUseClasses") {
options["noclasses"] = "false"
} else {
options["noclasses"] = "true"
}
}
if _, ok := options["encoding"]; !ok {
options["encoding"] = "utf8"
}
return options, nil
}
func parsePygmentsOpts(in string) (string, error) {
options, err := parseDefaultPygmentsOpts()
if err != nil {
return "", err
}
err = parseOptions(options, in)
if err != nil {
return "", err
}
return createOptionsString(options), nil
}
|