git.iko.soy/bat
on cec9cc0 help sign in
bat/src/output.rs
113 lines 3.8 kB history raw
1use std::env;
2use std::ffi::OsString;
3use std::io::{self, Write};
4use std::path::PathBuf;
5use std::process::{Child, Command, Stdio};
7use shell_words;
9use app::PagingMode;
10use errors::*;
12pub enum OutputType {
13 Pager(Child),
14 Stdout(io::Stdout),
17impl OutputType {
18 pub fn from_mode(mode: PagingMode, pager: Option<&str>) -> Result<Self> {
19 use self::PagingMode::*;
20 Ok(match mode {
21 Always => OutputType::try_pager(false, pager)?,
22 QuitIfOneScreen => OutputType::try_pager(true, pager)?,
23 _ => OutputType::stdout(),
24 })
25 }
27 /// Try to launch the pager. Fall back to stdout in case of errors.
28 fn try_pager(quit_if_one_screen: bool, pager_from_config: Option<&str>) -> Result<Self> {
29 let mut replace_arguments_to_less = false;
31 let pager_from_env = match (env::var("BAT_PAGER"), env::var("PAGER")) {
32 (Ok(bat_pager), _) => Some(bat_pager),
33 (_, Ok(pager)) => {
34 // less needs to be called with the '-R' option in order to properly interpret the
35 // ANSI color sequences printed by bat. If someone has set PAGER="less -F", we
36 // therefore need to overwrite the arguments and add '-R'.
37 //
38 // We only do this for PAGER (as it is not specific to 'bat'), not for BAT_PAGER
39 // or bats '--pager' command line option.
40 replace_arguments_to_less = true;
41 Some(pager)
42 }
43 _ => None,
44 };
46 let pager = pager_from_config
47 .map(|p| p.to_string())
48 .or(pager_from_env)
49 .unwrap_or(String::from("less"));
51 let pagerflags =
52 shell_words::split(&pager).chain_err(|| "Could not parse pager command.")?;
54 match pagerflags.split_first() {
55 Some((pager_name, args)) => {
56 let mut pager_path = PathBuf::from(pager_name);
58 if pager_path.file_stem() == Some(&OsString::from("bat")) {
59 pager_path = PathBuf::from("less");
60 }
62 let is_less = pager_path.file_stem() == Some(&OsString::from("less"));
64 let mut process = if is_less {
65 let mut p = Command::new(&pager_path);
66 if args.is_empty() || replace_arguments_to_less {
67 p.args(vec!["--RAW-CONTROL-CHARS", "--no-init"]);
68 if quit_if_one_screen {
69 p.arg("--quit-if-one-screen");
70 }
71 } else {
72 p.args(args);
73 }
74 p.env("LESSCHARSET", "UTF-8");
75 p
76 } else {
77 let mut p = Command::new(&pager_path);
78 p.args(args);
79 p
80 };
82 Ok(process
83 .stdin(Stdio::piped())
84 .spawn()
85 .map(OutputType::Pager)
86 .unwrap_or_else(|_| OutputType::stdout()))
87 }
88 None => Ok(OutputType::stdout()),
89 }
90 }
92 fn stdout() -> Self {
93 OutputType::Stdout(io::stdout())
94 }
96 pub fn handle(&mut self) -> Result<&mut Write> {
97 Ok(match *self {
98 OutputType::Pager(ref mut command) => command
99 .stdin
100 .as_mut()
101 .chain_err(|| "Could not open stdin for pager")?,
102 OutputType::Stdout(ref mut handle) => handle,
103 })
104 }
107impl Drop for OutputType {
108 fn drop(&mut self) {
109 if let OutputType::Pager(ref mut command) = *self {
110 let _ = command.wait();
111 }
112 }