*/
#define ISSPACE(x) (isspace((int) ((unsigned char)x)))
-#define ISBLANK(x) (isblank((int) ((unsigned char)x)))
#define ISDIGIT(x) (isdigit((int) ((unsigned char)x)))
#define ISALNUM(x) (isalnum((int) ((unsigned char)x)))
#define ISXDIGIT(x) (isxdigit((int) ((unsigned char)x)))
#define ISUPPER(x) (isupper((int) ((unsigned char)x)))
#define ISLOWER(x) (islower((int) ((unsigned char)x)))
+#ifdef HAVE_ISBLANK
+#define ISBLANK(x) (isblank((int) ((unsigned char)x)))
+#else
+#define ISBLANK(x) (int)((((unsigned char)x) == ' ') || \
+ (((unsigned char)x) == '\t'))
+#endif
+
/*
* Typedef to 'int' if sig_atomic_t is not an available 'typedefed' type.