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
|
// https://github.com/sharkdp/bat a1b9334a44a2c652f52dddaa83dbacba57372468
// src/output.rs
// See src/bat_utils/LICENSE
use std::env;
use std::ffi::OsString;
use std::io::{self, Write};
use std::path::PathBuf;
use std::process::{Child, Command, Stdio};
use super::less::retrieve_less_version;
use crate::config;
use crate::features::navigate;
#[derive(Debug, Clone, Copy, PartialEq)]
#[allow(dead_code)]
pub enum PagingMode {
Always,
QuitIfOneScreen,
Never,
}
use crate::errors::*;
pub enum OutputType {
Pager(Child),
Stdout(io::Stdout),
}
impl OutputType {
pub fn from_mode(
mode: PagingMode,
pager: Option<&str>,
config: &config::Config,
) -> Result<Self> {
use self::PagingMode::*;
Ok(match mode {
Always => OutputType::try_pager(false, pager, config)?,
QuitIfOneScreen => OutputType::try_pager(true, pager, config)?,
_ => OutputType::stdout(),
})
}
/// Try to launch the pager. Fall back to stdout in case of errors.
fn try_pager(
quit_if_one_screen: bool,
pager_from_config: Option<&str>,
config: &config::Config,
) -> Result<Self> {
let mut replace_arguments_to_less = false;
let pager_from_env = match (
env::var("DELTA_PAGER"),
env::var("BAT_PAGER"),
env::var("PAGER"),
) {
(Ok(delta_pager), _, _) => Some(delta_pager),
(_, Ok(bat_pager), _) => Some(bat_pager),
(_, _, Ok(pager)) => {
// less needs to be called with the '-R' option in order to properly interpret ANSI
// color sequences. If someone has set PAGER="less -F", we therefore need to
// overwrite the arguments and add '-R'.
// We only do this for PAGER, since it is used in other contexts.
replace_arguments_to_less = true;
Some(pager)
}
_ => None,
};
let pager_from_config = pager_from_config.map(|p| p.to_string());
if pager_from_config.is_some() {
replace_arguments_to_less = false;
}
let pager = pager_from_config
.or(pager_from_env)
.unwrap_or_else(|| String::from("less"));
let pagerflags =
shell_words::split(&pager).chain_err(|| "Could not parse pager command.")?;
match pagerflags.split_first() {
Some((pager_name, mut args)) => {
let mut pager_path = PathBuf::from(pager_name);
if pager_path.file_stem() == Some(&OsString::from("delta")) {
// This would be a non-terminating recursion.
pager_path = PathBuf::from("less");
args = &[];
}
let is_less = pager_path.file_stem() == Some(&OsString::from("less"));
let mut process = if is_less {
let mut p = Command::new(&pager_path);
if args.is_empty() || replace_arguments_to_less {
p.args(vec!["--RAW-CONTROL-CHARS"]);
// Passing '--no-init' fixes a bug with '--quit-if-one-screen' in older
// versions of 'less'. Unfortunately, it also breaks mouse-wheel support.
//
// See: http://www.greenwoodsoftware.com/less/news.530.html
//
// For newer versions (530 or 558 on Windows), we omit '--no-init' as it
// is not needed anymore.
match retrieve_less_version() {
None => {
p.arg("--no-init");
}
Some(version)
if (version < 530 || (cfg!(windows) && version < 558)) =>
{
p.arg("--no-init");
}
_ => {}
}
if quit_if_one_screen {
p.arg("--quit-if-one-screen");
}
} else {
p.args(args);
}
p.env("LESSCHARSET", "UTF-8");
p
} else {
let mut p = Command::new(&pager_path);
p.args(args);
p
};
if is_less && config.navigate {
if let Ok(hist_file) =
navigate::copy_less_hist_file_and_append_navigate_regexp(config)
{
process.env("LESSHISTFILE", hist_file);
}
}
Ok(process
.env("LESSANSIENDCHARS", "mK")
.stdin(Stdio::piped())
.spawn()
.map(OutputType::Pager)
.unwrap_or_else(|_| OutputType::stdout()))
}
None => Ok(OutputType::stdout()),
}
}
fn stdout() -> Self {
OutputType::Stdout(io::stdout())
}
pub fn handle(&mut self) -> Result<&mut dyn Write> {
Ok(match *self {
OutputType::Pager(ref mut command) => command
.stdin
.as_mut()
.chain_err(|| "Could not open stdin for pager")?,
OutputType::Stdout(ref mut handle) => handle,
})
}
}
impl Drop for OutputType {
fn drop(&mut self) {
if let OutputType::Pager(ref mut command) = *self {
let _ = command.wait();
}
}
}
|
