Make sure we check the ioctl term size result

This commit is contained in:
Ben S 2015-09-04 11:30:46 +01:00
parent d1e682b0c1
commit 65967355a8
3 changed files with 43 additions and 27 deletions

View File

@ -4,6 +4,7 @@
#![warn(trivial_casts, trivial_numeric_casts)]
#![warn(unused_extern_crates, unused_qualifications)]
#![warn(unused_results)]
extern crate ansi_term;
extern crate datetime;

View File

@ -28,6 +28,7 @@ pub struct Options {
impl Options {
/// Call getopts on the given slice of command-line strings.
#[allow(unused_results)]
pub fn getopts(args: &[String]) -> Result<(Options, Vec<String>), Misfire> {
let mut opts = getopts::Options::new();
opts.optflag("1", "oneline", "display one entry per line");

View File

@ -1,39 +1,53 @@
mod c {
use std::mem::zeroed;
use libc::{c_int, c_ushort, c_ulong, STDOUT_FILENO};
//! System calls for getting the terminal size.
//!
//! Getting the terminal size is performed using an ioctl command that takes
//! the file handle to the terminal -- which in this case, is stdout -- and
//! populates a structure containing the values.
//!
//! The size is needed when the user wants the output formatted into columns:
//! the default grid view, or the hybrid grid-details view.
// Getting the terminal size is done using an ioctl command that
// takes the file handle to the terminal (which in our case is
// stdout), and populates a structure with the values.
use std::mem::zeroed;
use libc::{c_int, c_ushort, c_ulong, STDOUT_FILENO};
pub struct Winsize {
pub ws_row: c_ushort,
pub ws_col: c_ushort,
/// The number of rows and columns of a terminal.
struct Winsize {
ws_row: c_ushort,
ws_col: c_ushort,
}
// Unfortunately the actual command is not standardised...
#[cfg(any(target_os = "linux", target_os = "android"))]
static TIOCGWINSZ: c_ulong = 0x5413;
#[cfg(any(target_os = "macos", target_os = "ios", target_os = "dragonfly"))]
static TIOCGWINSZ: c_ulong = 0x40087468;
extern {
pub fn ioctl(fd: c_int, request: c_ulong, ...) -> c_int;
}
/// Runs the ioctl command. Returns (0, 0) if output is not to a terminal, or
/// there is an error. (0, 0) is an invalid size to have anyway, which is why
/// it can be used as a nil value.
unsafe fn get_dimensions() -> Winsize {
let mut window: Winsize = zeroed();
let result = ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut window);
if result == -1 {
zeroed()
}
// Unfortunately the actual command is not standardised...
#[cfg(any(target_os = "linux", target_os = "android"))]
static TIOCGWINSZ: c_ulong = 0x5413;
#[cfg(any(target_os = "macos", target_os = "ios", target_os = "dragonfly"))]
static TIOCGWINSZ: c_ulong = 0x40087468;
extern {
pub fn ioctl(fd: c_int, request: c_ulong, ...) -> c_int;
}
pub unsafe fn dimensions() -> Winsize {
let mut window: Winsize = zeroed();
ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut window);
else {
window
}
}
/// Query the current processes's output, returning its width and height as a
/// number of characters. Returns None if the output isn't to a terminal.
/// number of characters. Returns `None` if the output isn't to a terminal.
pub fn dimensions() -> Option<(usize, usize)> {
let w = unsafe { c::dimensions() };
let w = unsafe { get_dimensions() };
if w.ws_col == 0 || w.ws_row == 0 {
None