Get terminal width for grid view (resolve #1)

1 files changed, 57 insertions, 0 deletions

diff --git a/src/term.rs b/src/term.rs
new file mode 100644
index 0000000..9e88adf
--- /dev/null
+++ b/src/term.rs
@@ -0,0 +1,57 @@
+
+mod c {
+    #![allow(non_camel_case_types)]
+    extern crate libc;
+    pub use self::libc::{
+        c_int,
+        c_ushort,
+        c_ulong,
+        STDOUT_FILENO,
+    };
+    use std::mem::zeroed;
+
+    // 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.
+
+    pub struct winsize {
+        pub ws_row: c_ushort,
+        pub ws_col: c_ushort,
+    }
+
+    // Unfortunately the actual command is not standardised...
+
+    #[cfg(target_os = "linux")]
+    #[cfg(target_os = "android")]
+    static TIOCGWINSZ: c_ulong = 0x5413;
+
+    #[cfg(target_os = "freebsd")]
+    #[cfg(target_os = "macos")]
+    static TIOCGWINSZ: c_ulong = 0x40087468;
+
+    extern {
+        pub fn ioctl(fd: c_int, request: c_ulong, ...) -> c_int;
+    }
+
+    pub fn dimensions() -> winsize {
+        unsafe {
+            let mut window: winsize = zeroed();
+            ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut window as *mut winsize);
+            window
+        }
+    }
+}
+
+pub fn dimensions() -> Option<(uint, uint)> {
+    let w = c::dimensions();
+
+    // If either of the dimensions is 0 then the command failed,
+    // usually because output isn't to a terminal (instead to a file
+    // or pipe or something)
+    if w.ws_col == 0 || w.ws_row == 0 {
+        None
+    }
+    else {
+        Some((w.ws_col as uint, w.ws_row as uint))
+    }
+}