command: add macro KEY_CTL()

I copied it from tig[1], which is licensed under the GPLv2+, so we
may use the code.

[1] http://jonas.nitro.dk/tig/

diff --git a/src/command.c b/src/command.c
index 0bb45bfbfc5acfcc5a18e7055d6e147c99494d9b..9ce7b0e6f1fb172c755ec41bae82aeb3c1f8845b 100644 (file)
--- a/src/command.c
+++ b/src/command.c
@@ -40,6 +40,8 @@
 #define DK(x)
 #endif
 
+#define KEY_CTL(x) ((x) & 0x1f) /* KEY_CTL(A) == ^A == \1 */
+
 #define BS   KEY_BACKSPACE
 #define DEL  KEY_DC
 #define UP   KEY_UP