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|
use std::io::{self, Write};
#[cfg(feature = "paging")]
use std::process::Child;
use crate::error::*;
#[cfg(feature = "paging")]
use crate::less::retrieve_less_version;
#[cfg(feature = "paging")]
use crate::paging::PagingMode;
#[cfg(feature = "paging")]
use crate::wrapping::WrappingMode;
#[cfg(feature = "paging")]
#[derive(Debug, PartialEq)]
enum SingleScreenAction {
Quit,
Nothing,
}
#[derive(Debug)]
pub enum OutputType {
#[cfg(feature = "paging")]
Pager(Child),
Stdout(io::Stdout),
}
impl OutputType {
#[cfg(feature = "paging")]
pub fn from_mode(
paging_mode: PagingMode,
wrapping_mode: WrappingMode,
pager: Option<&str>,
) -> Result<Self> {
use self::PagingMode::*;
Ok(match paging_mode {
Always => OutputType::try_pager(SingleScreenAction::Nothing, wrapping_mode, pager)?,
QuitIfOneScreen => {
OutputType::try_pager(SingleScreenAction::Quit, wrapping_mode, pager)?
}
_ => OutputType::stdout(),
})
}
/// Try to launch the pager. Fall back to stdout in case of errors.
#[cfg(feature = "paging")]
fn try_pager(
single_screen_action: SingleScreenAction,
wrapping_mode: WrappingMode,
pager_from_config: Option<&str>,
) -> Result<Self> {
use std::env;
use std::ffi::OsString;
use std::path::PathBuf;
use std::process::{Command, Stdio};
let mut replace_arguments_to_less = false;
let pager_from_env = match (env::var("BAT_PAGER"), env::var("PAGER")) {
(Ok(bat_pager), _) => Some(bat_pager),
(_, Ok(pager)) => {
// less needs to be called with the '-R' option in order to properly interpret the
// ANSI color sequences printed by bat. If someone has set PAGER="less -F", we
// therefore need to overwrite the arguments and add '-R'.
//
// We only do this for PAGER (as it is not specific to 'bat'), not for BAT_PAGER
// or bats '--pager' command line option.
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, args)) => {
let pager_path = PathBuf::from(pager_name);
if pager_path.file_stem() == Some(&OsString::from("bat")) {
return Err(ErrorKind::InvalidPagerValueBat.into());
}
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.arg("--RAW-CONTROL-CHARS");
if single_screen_action == SingleScreenAction::Quit {
p.arg("--quit-if-one-screen");
}
if wrapping_mode == WrappingMode::NoWrapping {
p.arg("--chop-long-lines");
}
// 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");
}
_ => {}
}
} else {
p.args(args);
}
p.env("LESSCHARSET", "UTF-8");
p
} else {
let mut p = Command::new(&pager_path);
p.args(args);
p
};
Ok(process
.stdin(Stdio::piped())
.spawn()
.map(OutputType::Pager)
.unwrap_or_else(|_| OutputType::stdout()))
}
None => Ok(OutputType::stdout()),
}
}
pub(crate) fn stdout() -> Self {
OutputType::Stdout(io::stdout())
}
#[cfg(feature = "paging")]
pub(crate) fn is_pager(&self) -> bool {
if let OutputType::Pager(_) = self {
true
} else {
false
}
}
#[cfg(not(feature = "paging"))]
pub(crate) fn is_pager(&self) -> bool {
false
}
pub fn handle(&mut self) -> Result<&mut dyn Write> {
Ok(match *self {
#[cfg(feature = "paging")]
OutputType::Pager(ref mut command) => command
.stdin
.as_mut()
.chain_err(|| "Could not open stdin for pager")?,
OutputType::Stdout(ref mut handle) => handle,
})
}
}
#[cfg(feature = "paging")]
impl Drop for OutputType {
fn drop(&mut self) {
if let OutputType::Pager(ref mut command) = *self {
let _ = command.wait();
}
}
}
|
