Also replace 'more' from PAGER with 'less'

But first do some quite significant refactorings to keep the code clean
and easy to understand.
This commit is contained in:
Martin Nordholts 2020-12-30 13:25:23 +01:00
parent 22bdc7c20f
commit bfa5342331
3 changed files with 150 additions and 93 deletions

View File

@ -11,7 +11,7 @@
- Make ./tests/syntax-tests/regression_test.sh work on recent versions of macOS, see #1443 (@Enselic)
- VimL syntax highlighting fix, see #1450 (@esensar)
- Print an 'Invalid syntax theme settings' error message if a custom theme is broken, see #614 (@Enselic)
- If `PAGER=most` (but not `BAT_PAGER` or `--pager`), silently use `less` instead since `most` does not support colors, see #1063 (@Enselic)
- If `PAGER` (but not `BAT_PAGER` or `--pager`) is `more` or `most`, silently use `less` instead to ensure support for colors, see #1063 (@Enselic)
## Other

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@ -48,43 +48,33 @@ impl OutputType {
wrapping_mode: WrappingMode,
pager_from_config: Option<&str>,
) -> Result<Self> {
use std::ffi::OsString;
use std::path::PathBuf;
use crate::pager::{self, PagerKind, PagerSource};
use std::process::{Command, Stdio};
use crate::pager::*;
let Pager { pager, source } = get_pager(pager_from_config);
let pager_opt =
pager::get_pager(pager_from_config).chain_err(|| "Could not parse pager command.")?;
let pagerflags =
shell_words::split(&pager).chain_err(|| "Could not parse pager command.")?;
let pager = match pager_opt {
Some(pager) => pager,
None => return Ok(OutputType::stdout()),
};
match pagerflags.split_first() {
Some((pager_name, pager_args)) => {
let mut pager_path = PathBuf::from(pager_name);
let mut args = pager_args;
let empty_args = vec![];
if pager_path.file_stem() == Some(&OsString::from("bat")) {
if pager.kind == PagerKind::Bat {
return Err(ErrorKind::InvalidPagerValueBat.into());
}
if pager_path.file_stem() == Some(&OsString::from("most")) && source == PagerSource::PagerEnvVar {
pager_path = PathBuf::from("less");
args = &empty_args;
}
let mut p = Command::new(pager.bin);
let args = pager.args;
let is_less = pager_path.file_stem() == Some(&OsString::from("less"));
let mut process = if is_less {
if pager.kind == PagerKind::Less {
// 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.
let replace_arguments_to_less = source == PagerSource::PagerEnvVar;
let replace_arguments_to_less = pager.source == PagerSource::PagerEnvVar;
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 {
@ -106,9 +96,7 @@ impl OutputType {
None => {
p.arg("--no-init");
}
Some(version)
if (version < 530 || (cfg!(windows) && version < 558)) =>
{
Some(version) if (version < 530 || (cfg!(windows) && version < 558)) => {
p.arg("--no-init");
}
_ => {}
@ -117,22 +105,15 @@ impl OutputType {
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())
Ok(p.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())

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@ -1,3 +1,6 @@
use shell_words::ParseError;
use std::env;
/// If we use a pager, this enum tells us from where we were told to use it.
#[derive(Debug, PartialEq)]
pub enum PagerSource {
@ -14,31 +17,104 @@ pub enum PagerSource {
Default,
}
/// We know about some pagers, for example 'less'. This is a list of all pagers we know about
#[derive(Debug, PartialEq)]
pub enum PagerKind {
/// The pager is ourselves
Bat,
/// less
Less,
/// more
More,
/// most
Most,
/// A pager we don't know about
Unknown,
}
impl PagerKind {
fn from_bin(bin: &str) -> PagerKind {
use std::ffi::OsStr;
use std::path::Path;
let stem = Path::new(bin)
.file_stem()
.unwrap_or_else(|| OsStr::new("unknown"));
if stem == OsStr::new("bat") {
PagerKind::Bat
} else if stem == OsStr::new("less") {
PagerKind::Less
} else if stem == OsStr::new("more") {
PagerKind::More
} else if stem == OsStr::new("most") {
PagerKind::Most
} else {
PagerKind::Unknown
}
}
}
/// A pager such as 'less', and from where we got it.
#[derive(Debug)]
pub struct Pager {
pub pager: String,
// The pager binary
pub bin: String,
// The pager binary arguments (that we might tweak)
pub args: Vec<String>,
// What pager this is
pub kind: PagerKind,
// From where this pager comes
pub source: PagerSource,
}
impl Pager {
fn new(pager: &str, source: PagerSource) -> Pager {
fn new(bin: &str, args: &[String], kind: PagerKind, source: PagerSource) -> Pager {
Pager {
pager: String::from(pager),
bin: String::from(bin),
args: args.to_vec(),
kind,
source,
}
}
}
/// Returns what pager to use, after looking at both config and environment variables.
pub fn get_pager(pager_from_config: Option<&str>) -> Pager {
match (
pager_from_config,
std::env::var("BAT_PAGER"),
std::env::var("PAGER"),
) {
(Some(config), _, _) => Pager::new(config, PagerSource::Config),
(_, Ok(bat_pager), _) => Pager::new(&bat_pager, PagerSource::BatPagerEnvVar),
(_, _, Ok(pager)) => Pager::new(&pager, PagerSource::PagerEnvVar),
_ => Pager::new("less", PagerSource::Default),
pub fn get_pager(config_pager: Option<&str>) -> Result<Option<Pager>, ParseError> {
let bat_pager = env::var("BAT_PAGER");
let pager = env::var("PAGER");
let (cmd, source) = match (config_pager, &bat_pager, &pager) {
(Some(config_pager), _, _) => (config_pager, PagerSource::Config),
(_, Ok(bat_pager), _) => (bat_pager.as_str(), PagerSource::BatPagerEnvVar),
(_, _, Ok(pager)) => (pager.as_str(), PagerSource::PagerEnvVar),
_ => ("less", PagerSource::Default),
};
let parts = shell_words::split(cmd)?;
match parts.split_first() {
Some((bin, args)) => {
let kind = PagerKind::from_bin(bin);
// 'more' and 'most' does not supports colors; automatically use 'less' instead
// if the problematic pager came from the generic PAGER env var
let no_color_support = kind == PagerKind::More || kind == PagerKind::Most;
let use_less_instead = no_color_support && source == PagerSource::PagerEnvVar;
Ok(Some(if use_less_instead {
let no_args = vec![];
Pager::new("less", &no_args, PagerKind::Less, PagerSource::PagerEnvVar)
} else {
Pager::new(bin, args, kind, source)
}))
}
None => Ok(None),
}
}