dialoguer/
edit.rs

1use std::{
2    env,
3    ffi::{OsStr, OsString},
4    fs,
5    io::{Read, Write},
6    process,
7};
8
9use crate::Result;
10
11/// Launches the default editor to edit a string.
12///
13/// ## Example
14///
15/// ```rust,no_run
16/// use dialoguer::Editor;
17///
18/// if let Some(rv) = Editor::new().edit("Enter a commit message").unwrap() {
19///     println!("Your message:");
20///     println!("{}", rv);
21/// } else {
22///     println!("Abort!");
23/// }
24/// ```
25pub struct Editor {
26    editor: OsString,
27    extension: String,
28    require_save: bool,
29    trim_newlines: bool,
30}
31
32fn get_default_editor() -> OsString {
33    if let Some(prog) = env::var_os("VISUAL") {
34        return prog;
35    }
36    if let Some(prog) = env::var_os("EDITOR") {
37        return prog;
38    }
39    if cfg!(windows) {
40        "notepad.exe".into()
41    } else {
42        "vi".into()
43    }
44}
45
46impl Default for Editor {
47    fn default() -> Self {
48        Self::new()
49    }
50}
51
52impl Editor {
53    /// Creates a new editor.
54    pub fn new() -> Self {
55        Self {
56            editor: get_default_editor(),
57            extension: ".txt".into(),
58            require_save: true,
59            trim_newlines: true,
60        }
61    }
62
63    /// Sets a specific editor executable.
64    pub fn executable<S: AsRef<OsStr>>(&mut self, val: S) -> &mut Self {
65        self.editor = val.as_ref().into();
66        self
67    }
68
69    /// Sets a specific extension
70    pub fn extension(&mut self, val: &str) -> &mut Self {
71        self.extension = val.into();
72        self
73    }
74
75    /// Enables or disables the save requirement.
76    pub fn require_save(&mut self, val: bool) -> &mut Self {
77        self.require_save = val;
78        self
79    }
80
81    /// Enables or disables trailing newline stripping.
82    ///
83    /// This is on by default.
84    pub fn trim_newlines(&mut self, val: bool) -> &mut Self {
85        self.trim_newlines = val;
86        self
87    }
88
89    /// Launches the editor to edit a string.
90    ///
91    /// Returns `None` if the file was not saved or otherwise the
92    /// entered text.
93    pub fn edit(&self, s: &str) -> Result<Option<String>> {
94        let mut f = tempfile::Builder::new()
95            .prefix("edit-")
96            .suffix(&self.extension)
97            .rand_bytes(12)
98            .tempfile()?;
99        f.write_all(s.as_bytes())?;
100        f.flush()?;
101        let ts = fs::metadata(f.path())?.modified()?;
102
103        let s: String = self.editor.clone().into_string().unwrap();
104        let (cmd, args) = match shell_words::split(&s) {
105            Ok(mut parts) => {
106                let cmd = parts.remove(0);
107                (cmd, parts)
108            }
109            Err(_) => (s, vec![]),
110        };
111
112        let rv = process::Command::new(cmd)
113            .args(args)
114            .arg(f.path())
115            .spawn()?
116            .wait()?;
117
118        if rv.success() && self.require_save && ts >= fs::metadata(f.path())?.modified()? {
119            return Ok(None);
120        }
121
122        let mut new_f = fs::File::open(f.path())?;
123        let mut rv = String::new();
124        new_f.read_to_string(&mut rv)?;
125
126        if self.trim_newlines {
127            let len = rv.trim_end_matches(&['\n', '\r'][..]).len();
128            rv.truncate(len);
129        }
130
131        Ok(Some(rv))
132    }
133}
dialoguer/edit.rs

dialoguer/
edit.rs
