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extern crate libc;
use std::ffi::CString;
use std::ptr;
mod helper;
use helper::{getenv, fork, close, dup2, execvp, pipe, default_pager};
const DEFAULT_PAGER_ENV: &'static str = "PAGER";
#[derive(Debug, Default)]
pub struct Pager {
env: String,
ok: bool,
}
impl Pager {
pub fn new() -> Self {
Pager {
env: String::from(DEFAULT_PAGER_ENV),
ok: true,
}
}
pub fn env(env: &str) -> Self {
Pager {
env: String::from(env),
ok: true,
}
}
pub fn ok(&self) -> bool {
self.ok
}
pub fn setup(&mut self) {
if let Some(pager) = self.get_pager() {
let (pager_stdin, main_stdout) = pipe();
let pid = fork();
match pid {
-1 => {
close(pager_stdin);
close(main_stdout);
self.ok = false
}
0 => {
dup2(main_stdout, libc::STDOUT_FILENO);
close(pager_stdin);
}
_ => {
let argv = vec![pager.as_ptr(), ptr::null()];
dup2(pager_stdin, libc::STDIN_FILENO);
close(main_stdout);
execvp(argv);
}
}
}
}
fn get_pager(&self) -> Option<CString> {
getenv(&self.env).or_else(default_pager)
}
}