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comparison cmd/sievemgr/edit.go @ 8:8caacf702c0d

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Add edit subcommand for interactive editing of a script
author Guido Berhoerster <guido+sievemgr@berhoerster.name>
date Fri, 13 Nov 2020 10:49:08 +0100
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children 29769b9e2f09
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7:3abc8be485c0 8:8caacf702c0d
1 // Copyright (C) 2020 Guido Berhoerster <guido+sievemgr@berhoerster.name>
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining
4 // a copy of this software and associated documentation files (the
5 // "Software"), to deal in the Software without restriction, including
6 // without limitation the rights to use, copy, modify, merge, publish,
7 // distribute, sublicense, and/or sell copies of the Software, and to
8 // permit persons to whom the Software is furnished to do so, subject to
9 // the following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included
12 // in all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
17 // IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
18 // CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
19 // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
20 // SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21
22 package main
23
24 import (
25 "fmt"
26 "io"
27 "io/ioutil"
28 "os"
29 "os/exec"
30 "path/filepath"
31 "runtime"
32 "strings"
33
34 "go.guido-berhoerster.org/managesieve"
35 "go.guido-berhoerster.org/sievemgr/cmd/sievemgr/internal/config"
36 "golang.org/x/crypto/ssh/terminal"
37 )
38
39 func init() {
40 cmdEdit.Flag.StringVar(&acctName, "a", "", "Select the account")
41 }
42
43 var cmdEdit = &command{
44 UsageLine: "edit [options] name",
45 Run: runEdit,
46 }
47
48 func promptYesNo(prompt string) (yesNo bool, err error) {
49 var tty *os.File
50 var r io.Reader
51 var w io.Writer
52 if runtime.GOOS == "windows" {
53 r = os.Stdin
54 w = os.Stdout
55 } else {
56 tty, err = os.OpenFile("/dev/tty", os.O_RDWR, 0666)
57 if err != nil {
58 return
59 }
60 r = tty
61 w = tty
62 defer tty.Close()
63 }
64
65 for {
66 io.WriteString(w, prompt)
67
68 var response string
69 _, err = fmt.Fscanln(r, &response)
70 if err != nil {
71 err = fmt.Errorf("failed to read response: %s", err)
72 return
73 }
74
75 switch strings.ToLower(response) {
76 case "y", "yes":
77 yesNo = true
78 return
79 case "n", "no":
80 return
81 }
82 }
83 }
84
85 func getScript(acct *config.Account, scriptName string) (string, error) {
86 c, err := dialPlainAuth(acct)
87 if err != nil {
88 return "", err
89 }
90 defer c.Logout()
91
92 return c.GetScript(scriptName)
93 }
94
95 func readScript(filename string) (string, error) {
96 f, err := os.Open(filename)
97 if err != nil {
98 return "", err
99 }
100 defer f.Close()
101
102 return readLimitedString(f, managesieve.ReadLimit)
103 }
104
105 func putScript(acct *config.Account, scriptName, script string) (string, error) {
106 c, err := dialPlainAuth(acct)
107 if err != nil {
108 return "", err
109 }
110 defer c.Logout()
111
112 return c.PutScript(scriptName, script)
113 }
114
115 func runEdit(cmd *command, args []string) error {
116 if len(args) != 1 {
117 return usageError("invalid number of arguments")
118 }
119
120 scriptName := args[0]
121
122 if !terminal.IsTerminal(int(os.Stdin.Fd())) ||
123 !terminal.IsTerminal(int(os.Stdout.Fd())) {
124 return fmt.Errorf("the edit subcommand can only be used interactively\n")
125 }
126
127 editor := os.Getenv("EDITOR")
128 if editor == "" {
129 return fmt.Errorf("EDITOR environment variable not set")
130 }
131
132 acct, err := getAccount(&conf, acctName)
133 if err != nil {
134 return err
135 }
136
137 if err := lookupHostPort(acct); err != nil {
138 return err
139 }
140
141 if err := readPassword(acct); err != nil {
142 return err
143 }
144
145 c, err := dialPlainAuth(acct)
146 if err != nil {
147 return err
148 }
149 defer c.Logout()
150
151 script, err := getScript(acct, scriptName)
152 if err != nil {
153 return err
154 }
155
156 tmpDir, err := ioutil.TempDir(os.TempDir(), "sievemgr*")
157 if err != nil {
158 return fmt.Errorf("failed to create temporary directory: %s", err)
159 }
160
161 tmpFile := filepath.Join(tmpDir, scriptName)
162 if err = ioutil.WriteFile(tmpFile, []byte(script), 0640); err != nil {
163 return fmt.Errorf("failed to create script file: %s", err)
164 }
165 defer func() {
166 // show filename if an error has occured and the file is
167 // preserved
168 if tmpFile != "" {
169 fmt.Fprintf(os.Stderr,
170 "the script has been preserved as %s\n",
171 tmpFile)
172 }
173 }()
174
175 // modification time is used to detect changes
176 info, err := os.Stat(tmpFile)
177 if err != nil {
178 return fmt.Errorf("failed to stat file: %s", err)
179 }
180 origModTime := info.ModTime()
181
182 for {
183 cmd := exec.Command(editor, tmpFile)
184 cmd.Stdin = os.Stdin
185 cmd.Stdout = os.Stdout
186 cmd.Stderr = os.Stderr
187 if err := cmd.Run(); err != nil {
188 return fmt.Errorf("failed to run editor: %s", err)
189 }
190
191 // quit if the script has not been changed
192 if info, err := os.Stat(tmpFile); err != nil {
193 return fmt.Errorf("failed to stat file: %s", err)
194 } else if info.ModTime() == origModTime {
195 fmt.Fprintln(os.Stderr, "aborting, script was not modified")
196 break
197 }
198
199 script, err = readScript(tmpFile)
200 if err != nil {
201 return fmt.Errorf("failed to read script: %s", err)
202 }
203
204 warnings, err := putScript(acct, scriptName, script)
205 if err != nil {
206 // show error and try again if the script was rejected
207 // by the server
208 fmt.Fprintln(os.Stderr, err)
209 yesNo, err := promptYesNo("edit again [y/n]? ")
210 if err != nil {
211 return err
212 } else if !yesNo {
213 return fmt.Errorf("script not saved")
214 }
215 } else if warnings != "" {
216 fmt.Fprintln(os.Stderr, warnings)
217 break
218 } else {
219 break
220 }
221 }
222
223 os.RemoveAll(tmpDir)
224 tmpFile = ""
225
226 return nil
227 }