Fixed lower/upper case functions to use locale.

https://github.com/mpapierski/ftpproxy/commit/f606f57b47b3f286ea1ba5b50728d6f3cb9a313d
Author: Michał Papierski <michal@papierski.net>
Date:   Sat Aug 23 13:38:44 2014 +0200

Previous version hardcoded some letters from alphabet and added its
own (most probably German special characters). This is better
because locale is used for the conversion.

--- src/lib.c
+++ src/lib.c
@@ -59,122 +59,33 @@ void *reallocate(void *p, size_t size)
 	return (p);
 }
 
-
-
-static unsigned int lower[256], upper[256];
-
-static int _init_upper()
-{
-	unsigned int c;
-	
-	DEBUG( fprintf (stderr, "init upper[]\n"); )
-	for (c = 0; c < 256; c++)
-		upper[c] = c;
-
-	DEBUG( fprintf (stderr, "init uppercase letters\n"); )
-	for (c = 'a'; c < 'z'+1; c++)
-		upper[c] = 'A' + (c - 'a');
-
-	DEBUG( fprintf (stderr, "init umlaute\n"); )
-	upper[c = (unsigned char) 'ä'] = 'Ä';
-	upper[c = (unsigned char) 'ö'] = 'Ö';
-	upper[c = (unsigned char) 'ü'] = 'Ü';
-
-	DEBUG( fprintf (stderr, "init upper[] complete\n"); )
-	return (0);
-}
-
-static int _init_lower()
-{
-	unsigned int c;
-	
-	DEBUG( fprintf (stderr, "init lower[]\n"); )
-	for (c = 0; c < 256; c++)
-		lower[c] = c;
-
-	DEBUG( fprintf (stderr, "init uppercase letters\n"); )
-	for (c = 'A'; c < 'Z'+1; c++)
-		lower[c] = 'a' + (c - 'A');
-
-	DEBUG( fprintf (stderr, "init umlaute\n"); )
-	lower[c = (unsigned char) 'Ä'] = 'ä';
-	lower[c = (unsigned char) 'Ö'] = 'ö';
-	lower[c = (unsigned char) 'Ü'] = 'ü';
-
-	DEBUG( fprintf (stderr, "init upper[] complete\n"); )
-	return (0);
-}
-
-
-unsigned int uppercase(unsigned int c)
-{
-	if (upper['0'] == 0)
-		_init_upper();
-
-	return (upper[c]);
-}
-
-int isuppercase(unsigned int c)
-{
-	if (upper['0'] == 0)
-		_init_upper();
-
-	return (upper[c] == c);
-}
-
-unsigned int lowercase(unsigned int c)
-{
-	if (lower['0'] == 0)
-		_init_lower();
-
-	return (lower[c]);
-}
-
-int islowercase(unsigned int c)
-{
-	if (lower['0'] == 0)
-		_init_lower();
-
-	return (lower[c] == c);
-}
-
 char *strlwr(char *string)
 {
-	unsigned int c;
-	unsigned char *p;
+	int c;
 
-	if (lower['0'] == 0)
-		_init_lower();
-		
-	p = string;
-	while ((c = *p) != 0) {
-		*p++ = lower[c];
+	while ((c = *string) != 0) {
+		*string++ = tolower(c);
 		}
 
 	return (string);
-}	
+}
 
 char *strupr(char *string)
 {
-	unsigned int c;
-	unsigned char *p;
+	int c;
 
-	if (upper['0'] == 0)
-		_init_upper();
-		
-	p = string;
-	while ((c = *p) != 0) {
-		*p++ = upper[c];
+	while ((c = *string) != 0) {
+		*string++ = toupper(c);
 		}
 
 	return (string);
-}	
+}
 
 char *skip_ws(char *string)
 {
-	unsigned int c;
+	int c;
 
-	while ((c = *string) == ' '  ||  c == '\t')
+	while (isspace(c = *string))
 		string++;
 
 	return (string);
@@ -185,6 +95,7 @@ char *noctrl(char *buffer)
 	int	len, i;
 	unsigned char *p;
 
+	// TODO: Use iscntrl here. iscntrl(32) returns 0 so figure out why space is converted to null byte too.
 	if ((p = buffer) == NULL)
 		return (NULL);
 
--- src/lib.h
+++ src/lib.h
@@ -32,10 +32,6 @@ extern int verbose;
 void *allocate(size_t size);
 void *reallocate(void *p, size_t size);
 
-unsigned int uppercase(unsigned int c);
-int isuppercase(unsigned int c);
-unsigned int lowercase(unsigned int c);
-int islowercase(unsigned int c);
 char *strlwr(char *string);
 char *strupr(char *string);
 char *skip_ws(char *string);