look(1): eliminate FOLD and DICT macros

[Todd C. Miller]

There's no need to check for isascii() with ANSI ctype macros/functions.
Eliminating the macros makes the code clearer.

 - todd

Index: usr.bin/look/look.c
===================================================================
RCS file: /cvs/src/usr.bin/look/look.c,v
retrieving revision 1.18
diff -u -p -u -r1.18 look.c
--- usr.bin/look/look.c 9 Oct 2015 01:37:08 -0000       1.18
+++ usr.bin/look/look.c 7 Sep 2016 21:44:53 -0000
@@ -57,20 +57,9 @@
 
 #include "pathnames.h"
 
-/*
- * FOLD and DICT convert characters to a normal form for comparison,
- * according to the user specified flags.
- * 
- * DICT expects integers because it uses a non-character value to
- * indicate a character which should not participate in comparisons.
- */
 #define        EQUAL           0
 #define        GREATER         1
 #define        LESS            (-1)
-#define NO_COMPARE     (-2)
-
-#define        FOLD(c) (isascii(c) && isupper(c) ? tolower(c) : (c))
-#define        DICT(c) (isascii(c) && isalnum(c) ? (c) : NO_COMPARE)
 
 int dflag, fflag;
 
@@ -147,10 +136,8 @@ look(char *string, char *front, char *ba
        /* Reformat string to avoid doing it multiple times later. */
        for (readp = writep = string; ch = *readp++;) {
                if (fflag)
-                       ch = FOLD((unsigned char)ch);
-               if (dflag)
-                       ch = DICT((unsigned char)ch);
-               if (ch != NO_COMPARE)
+                       ch = tolower((unsigned char)ch);
+               if (!dflag || isalnum((unsigned char)ch))
                        *(writep++) = ch;
        }
        *writep = '\0';
@@ -294,11 +281,8 @@ compare(char *s1, char *s2, char *back)
        for (; *s1 && s2 < back && *s2 != '\n'; ++s1, ++s2) {
                ch = *s2;
                if (fflag)
-                       ch = FOLD((unsigned char)ch);
-               if (dflag)
-                       ch = DICT((unsigned char)ch);
-
-               if (ch == NO_COMPARE) {
+                       ch = tolower((unsigned char)ch);
+               if (dflag && !isalnum((unsigned char)ch)) {
                        ++s2;           /* Ignore character in comparison. */
                        continue;
                }