add libc building to agbcc.

libc/string/strcasecmp.c

@@ -0,0 +1,56 @@
+/*
+FUNCTION
+	<<strcasecmp>>---case insensitive character string compare
+	
+INDEX
+	strcasecmp
+
+ANSI_SYNOPSIS
+	#include <string.h>
+	int strcasecmp(const char *<[a]>, const char *<[b]>);
+
+TRAD_SYNOPSIS
+	#include <string.h>
+	int strcasecmp(<[a]>, <[b]>)
+	char *<[a]>;
+	char *<[b]>;
+
+DESCRIPTION
+	<<strcasecmp>> compares the string at <[a]> to
+	the string at <[b]> in a case-insensitive manner.
+
+RETURNS 
+
+	If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
+	both are converted to upper case), <<strcasecmp>> returns a
+	number greater than zero.  If the two strings match,
+	<<strcasecmp>> returns zero.  If <<*<[a]>>> sorts
+	lexicographically before <<*<[b]>>>, <<strcasecmp>> returns a
+	number less than zero.
+
+PORTABILITY
+<<strcasecmp>> is in the Berkeley Software Distribution.
+
+<<strcasecmp>> requires no supporting OS subroutines. It uses
+tolower() from elsewhere in this library.
+
+QUICKREF
+	strcasecmp 
+*/
+
+#include <string.h>
+#include <ctype.h>
+
+int
+_DEFUN (strcasecmp, (s1, s2),
+	_CONST char *s1 _AND
+	_CONST char *s2)
+{
+  while (*s1 != '\0' && tolower(*s1) == tolower(*s2))
+    {
+      s1++;
+      s2++;
+    }
+
+  return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
+}