add GIO_CMAP wrapper

We should be able to get the currently active palette.

1 files changed, 16 insertions, 0 deletions

diff --git a/src/vtcol.rs b/src/vtcol.rs
index e1b4d6a..361b8fe 100644
--- a/src/vtcol.rs
+++ b/src/vtcol.rs
@@ -21,7 +21,9 @@ const RAW_COLEXPR_SIZE: usize = 6; // e. g. 0xBADF00
 
 type RawPalette<'a> = [&'a str; PALETTE_SIZE];
 
+/* XXX: can we get these into ``libc``? */
 const KDGKBTYPE: libc::c_int = 0x4b33; /* kd.h */
+const GIO_CMAP: libc::c_int = 0x00004B70; /* kd.h */
 const PIO_CMAP: libc::c_int = 0x00004B71; /* kd.h */
 const KB_101: libc::c_char = 0x0002; /* kd.h */
 const O_NOCTTY: libc::c_int = 0o0400; /* fcntl.h */
@@ -609,6 +611,20 @@ fn ioctl_pio_cmap(fd: Fd, pal: &Palette) -> Result<()>
     }
 }
 
+fn ioctl_gio_cmap(fd: Fd) -> Result<Palette>
+{
+    let mut pal = Palette::new();
+
+    if unsafe { ioctl(fd, GIO_CMAP, std::mem::transmute(&mut pal)) } < 0 {
+        Err(anyhow!(
+            "ioctl(GIO_CMAP) failed to get current palette: {}",
+            Error::last_os_error()
+        ))
+    } else {
+        Ok(pal)
+    }
+}
+
 fn main() -> Result<()>
 {
     let job = Job::from_argv()?;