freebsd-dev/lib/libncurses/lib_unctrl.c
1994-10-07 08:58:58 +00:00

27 lines
596 B
C

#include <ctype.h>
#include <unctrl.h>
char *
unctrl(register unsigned char uch)
{
static char buffer[3] = "^x";
if (isgraph(uch)) {
/*
* Printable character. Simply return the character as a one-character
* string.
*/
buffer[1] = uch;
return &buffer[1];
}
uch &= ~0x80;
/*
* It is a control character. DEL is handled specially (^?). All others
* use ^x notation, where x is the character code for the control character
* with 0x40 ORed in. (Control-A becomes ^A etc.).
*/ buffer[1] = (uch == 0x7F ? '?' : (uch | 0x40));
return buffer;
}