+
+/*
+ * Convert a string to a long that may not be <0.
+ * If the string is invalid, or is less than 0, return -1.
+ */
+int
+mandoc_strntou(const char *p, size_t sz, int base)
+{
+ char buf[32];
+ char *ep;
+ long v;
+
+ if (sz > 31)
+ return(-1);
+
+ memcpy(buf, p, sz);
+ buf[(int)sz] = '\0';
+
+ errno = 0;
+ v = strtol(buf, &ep, base);
+
+ if (buf[0] == '\0' || *ep != '\0')
+ return(-1);
+
+ if ((errno == ERANGE &&
+ (v == LONG_MAX || v == LONG_MIN)) ||
+ (v > INT_MAX || v < 0))
+ return(-1);
+
+ return((int)v);
+}
+