+/* HasPrefix returns true if non-NULL s starts with non-NULL prefix. */
+bool HasPrefix(const char *s, const char *prefix)
+{
+ while (*s && *s == *prefix) {
+ s++;
+ prefix++;
+ }
+
+ return *prefix == '\0';
+}
+
+
+/* HasSuffix returns true if non-NULL s ends with non-NULL suffix. */
+bool HasSuffix(const char *s, const char *suffix)
+{
+ size_t ls, lsuf;
+
+ ls = strlen(s);
+ lsuf = strlen(suffix);
+
+ return lsuf <= ls && !strcmp(s + ls - lsuf, suffix);
+}
+
+
+/* HasSuffixC returns true if non-NULL string s ends with a c before the
+ * terminating NUL. */
+bool HasSuffixC(const char *s, int c)
+{
+ return *s && s[strlen(s) - 1] == c;
+}
+
+
+/* TrimSuffixC deletes c from the end of non-NULL string s if it's
+ * present, shortening s by 1. Only one instance of c is removed. */
+void TrimSuffixC(char *s, int c)
+{
+ if (!*s)
+ return;
+
+ s += strlen(s) - 1;
+ if (*s == c)
+ *s = '\0';
+}
+
+
+/* ToLower runs all of s through tolower(3). */
+void ToLower(char *s)
+{
+ unsigned char *b;
+
+ for (b = (unsigned char *)s; (*b = tolower(*b)); b++)
+ ;
+}
+
+
+/* ToUpper runs all of s through toupper(3). */
+void ToUpper(char *s)
+{
+ unsigned char *b;
+
+ for (b = (unsigned char *)s; (*b = toupper(*b)); b++)
+ ;
+}
+
+