+/* truncpy copies at most size - 1 chars from non-NULL src to non-NULL,
+ * non-overlapping, dst, and ensures dst is NUL terminated. If size is
+ * zero then it aborts as dst cannot be NUL terminated.
+ *
+ * It's to be used when truncation is intended and correct, e.g.
+ * reporting a possibly very long external string back to the user. One
+ * of its advantages over strncpy(3) is it doesn't pad in the common
+ * case of no truncation. */
+void trunccpy(char *dst, const char *src, size_t size)
+{
+ if (!size) {
+ inform("trunccpy: zero-length destination: \"%.20s\"",
+ src ? src : "null");
+ abort();
+ }
+
+ if (strnlen(src, size) < size) {
+ strcpy(dst, src);
+ } else {
+ memcpy(dst, src, size - 1);
+ dst[size - 1] = '\0';
+ }
+}
+
+
+/* has_prefix returns true if non-NULL s starts with non-NULL prefix. */
+bool has_prefix(const char *s, const char *prefix)
+{
+ while (*s && *s == *prefix) {
+ s++;
+ prefix++;
+ }
+
+ return *prefix == '\0';
+}
+
+
+/* has_suffix returns true if non-NULL s ends with non-NULL suffix. */
+bool has_suffix(const char *s, const char *suffix)
+{
+ size_t ls, lsuf;
+
+ ls = strlen(s);
+ lsuf = strlen(suffix);
+
+ return lsuf <= ls && !strcmp(s + ls - lsuf, suffix);
+}
+
+
+/* has_suffix_c returns true if non-NULL string s ends with a c before the
+ * terminating NUL. */
+bool has_suffix_c(const char *s, int c)
+{
+ return *s && s[strlen(s) - 1] == c;
+}
+
+
+/* trim_suffix_c 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 trim_suffix_c(char *s, int c)
+{
+ if (!*s)
+ return;
+
+ s += strlen(s) - 1;
+ if (*s == c)
+ *s = '\0';
+}
+
+
+/* to_lower runs all of s through tolower(3). */
+void to_lower(char *s)
+{
+ unsigned char *b;
+
+ for (b = (unsigned char *)s; (*b = tolower(*b)); b++)
+ ;
+}
+
+
+/* to_upper runs all of s through toupper(3). */
+void to_upper(char *s)
+{
+ unsigned char *b;
+
+ for (b = (unsigned char *)s; (*b = toupper(*b)); b++)
+ ;
+}
+
+