iron out bugs

npc/npc.1

@@ -32,6 +32,10 @@ option prints tab characters as "^I" rather than a literal horizontal tab.
 Npc prints a debug message and exits with the appropriate sysexits(3) error
 code in the event of an error, otherwise it exits successfully.
 
+.SH BUGS
+
+Npc operates in single-byte chunks regardless of intended encoding.
+
 .SH STANDARDS
 
 None.

npc/npc.c

@@ -31,12 +31,12 @@ usage:		fprintf(stderr,
 	}
 
 	while((c = getc(stdin)) != EOF){
-		if(c > 127){
+		if((c & 0x80) != 0){
 			fputs("M-", stdout);
-			c -= 128;
+			c ^= 0x80; /* 0b 1000 0000 */
 		}
 		switch(c){
-		case 127:	fputs("^?", stdout);
+		case 0x7f:	fputs("^?", stdout);
 				break;
 		case '\n':	if(showend)
 					putc('$', stdout);