allow setting the terminal size

6 files changed, 73 insertions, 11 deletions

diff --git a/Cargo.toml b/Cargo.toml
index a71c256..d1673b2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,5 +5,6 @@ authors = ["Jesse Luehrs <doy@tozt.net>"]
 edition = "2018"
 
 [dependencies]
+libc = "*"
 nix = "0.17"
 thiserror = "1.0"
diff --git a/examples/basic.rs b/examples/basic.rs
index d3d795a..2f71bb4 100644
--- a/examples/basic.rs
+++ b/examples/basic.rs
@@ -4,9 +4,13 @@ use std::os::unix::io::AsRawFd as _;
 use pty_process::Command as _;
 
 fn main() {
-    let mut child = std::process::Command::new("cat")
-        // .args(&["--color=auto"])
-        .spawn_pty()
+    let mut child = std::process::Command::new("perl")
+        .args(&[
+            "-MTerm::ReadKey",
+            "-E",
+            "my @size = GetTerminalSize; say for @size",
+        ])
+        .spawn_pty(Some(pty_process::Size::new(24, 80)))
         .unwrap();
     let mut buf = [0_u8; 4096];
     let pty = child.pty().as_raw_fd();
diff --git a/src/command.rs b/src/command.rs
index d02df2d..926e097 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -4,13 +4,13 @@ use std::os::unix::io::{AsRawFd as _, FromRawFd as _};
 use std::os::unix::process::CommandExt as _;
 
 pub trait Command {
-    fn spawn_pty(&mut self) -> Result<Child>;
+    fn spawn_pty(&mut self, size: Option<crate::pty::Size>) -> Result<Child>;
 }
 
 impl Command for std::process::Command {
-    fn spawn_pty(&mut self) -> Result<Child> {
+    fn spawn_pty(&mut self, size: Option<crate::pty::Size>) -> Result<Child> {
         let pty = crate::pty::Pty::new()?;
-        let pts = pty.pts()?;
+        let pts = pty.pts(size)?;
 
         let pt_fd = pty.pt().as_raw_fd();
         let pts_fd = pts.as_raw_fd();
diff --git a/src/error.rs b/src/error.rs
index b414cf9..97fd8a0 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -6,6 +6,9 @@ pub enum Error {
     #[error("error opening pts at {0}")]
     OpenPts(std::path::PathBuf, #[source] std::io::Error),
 
+    #[error("error setting terminal size")]
+    SetTermSize(#[source] nix::Error),
+
     #[error("error spawning subprocess")]
     Spawn(#[source] std::io::Error),
 }
diff --git a/src/lib.rs b/src/lib.rs
index 2e6d894..bcf5ce9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,4 +3,4 @@ pub use command::Command;
 mod error;
 pub use error::{Error, Result};
 mod pty;
-pub use pty::Pty;
+pub use pty::{Pty, Size};
diff --git a/src/pty.rs b/src/pty.rs
index d76aa6b..a557f56 100644
--- a/src/pty.rs
+++ b/src/pty.rs
@@ -1,6 +1,49 @@
 use crate::error::*;
 
-use std::os::unix::io::{FromRawFd as _, IntoRawFd as _};
+use std::os::unix::io::{AsRawFd as _, FromRawFd as _, IntoRawFd as _};
+
+pub struct Size {
+    row: u16,
+    col: u16,
+    xpixel: u16,
+    ypixel: u16,
+}
+
+impl Size {
+    pub fn new(row: u16, col: u16) -> Self {
+        Self {
+            row,
+            col,
+            xpixel: 0,
+            ypixel: 0,
+        }
+    }
+
+    pub fn new_with_pixel(
+        row: u16,
+        col: u16,
+        xpixel: u16,
+        ypixel: u16,
+    ) -> Self {
+        Self {
+            row,
+            col,
+            xpixel,
+            ypixel,
+        }
+    }
+}
+
+impl From<Size> for nix::pty::Winsize {
+    fn from(size: Size) -> Self {
+        Self {
+            ws_row: size.row,
+            ws_col: size.col,
+            ws_xpixel: size.xpixel,
+            ws_ypixel: size.ypixel,
+        }
+    }
+}
 
 pub struct Pty {
     pt: std::fs::File,
@@ -29,11 +72,22 @@ impl Pty {
         &self.pt
     }
 
-    pub fn pts(&self) -> Result<std::fs::File> {
-        Ok(std::fs::OpenOptions::new()
+    pub fn pts(&self, size: Option<Size>) -> Result<std::fs::File> {
+        let fh = std::fs::OpenOptions::new()
             .read(true)
             .write(true)
             .open(&self.ptsname)
-            .map_err(|e| Error::OpenPts(self.ptsname.clone(), e))?)
+            .map_err(|e| Error::OpenPts(self.ptsname.clone(), e))?;
+        let fd = fh.as_raw_fd();
+        if let Some(size) = size {
+            let size = size.into();
+            unsafe {
+                set_term_size(fd, &size as *const nix::pty::Winsize)
+                    .map_err(Error::SetTermSize)?;
+            }
+        }
+        Ok(fh)
     }
 }
+
+nix::ioctl_write_ptr_bad!(set_term_size, libc::TIOCSWINSZ, nix::pty::Winsize);