String: added nxt_atoul().

This is similar to atoi(3) in usage, except that:

-  It's safe (doesn't have Undefined Behavior).
-  It receives a nxt_str_t instead of a string.
-  The base is 0, not 10.

Errors are reported with the same error codes as in strtou(3bsd), but
they are reported via errno, instead of passing a pointer to an int.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

2 files changed, 41 insertions, 0 deletions

diff --git a/src/nxt_string.c b/src/nxt_string.c
index ed4ff955..3a3fd5bf 100644
--- a/src/nxt_string.c
+++ b/src/nxt_string.c
@@ -8,8 +8,13 @@
 #include <nxt_main.h>
 
 #include <errno.h>
+#include <stdio.h>
 #include <stdlib.h>
 
+#include <nxt_unit_cdefs.h>
+
+#include "nxt_string.h"
+
 
 static inline unsigned long nxt_strtoul_noneg(const char *nptr,
     char **restrict endptr, int base);
@@ -852,6 +857,39 @@ nxt_base64_decode(u_char *dst, u_char *src, size_t length)
 }
 
 
+unsigned long
+nxt_atoul(const nxt_str_t *s)
+{
+    int            e;
+    char           *endptr;
+    unsigned long  ul;
+    char           buf[BUFSIZ];
+
+    if (s == NULL || s->length >= nxt_nitems(buf)) {
+        errno = ECANCELED;
+        return 0;
+    }
+
+    stpcpy(nxt_cpymem(buf, s->start, s->length), "");
+
+    e = errno;
+    errno = 0;
+    ul = nxt_strtoul_noneg(buf, &endptr, 0);
+
+    if (endptr == buf) {
+        errno = ECANCELED;
+    } else if (errno == ERANGE) {
+        errno = ERANGE;
+    } else if (*endptr == '\0') {
+        errno = ENOTSUP;
+    } else {
+        errno = e;
+    }
+
+    return ul;
+}
+
+
 static inline unsigned long
 nxt_strtoul_noneg(const char *nptr, char **restrict endptr, int base)
 {
diff --git a/src/nxt_string.h b/src/nxt_string.h
index 18ea5490..8afdc1e7 100644
--- a/src/nxt_string.h
+++ b/src/nxt_string.h
@@ -161,6 +161,9 @@ NXT_EXPORT nxt_bool_t nxt_is_complex_uri_encoded(u_char *s, size_t length);
 
 NXT_EXPORT ssize_t nxt_base64_decode(u_char *dst, u_char *src, size_t length);
 
+NXT_EXPORT unsigned long nxt_atoul(const nxt_str_t *s);
+
+
 extern const uint8_t  nxt_hex2int[256];