diff --git a/include/ucore/read_file.h b/include/ucore/read_file.h
index 9e1ea10..26e4987 100644
--- a/include/ucore/read_file.h
+++ b/include/ucore/read_file.h
@@ -21,6 +21,14 @@ extern "C" {
 char *
 uc_read_file(const char *file_name, size_t *length, size_t max);
 
+/** Read the content of a file descriptor as a stream.
+ * @see uc_read_file
+ * This is similar but reads from a file descriptor,
+ * of any type as long as it supports the read() call.
+ */
+char *
+uc_read_fd(int fd, size_t *length, size_t max);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/ucore/utils.h b/include/ucore/utils.h
index e2b6592..70e5ca9 100644
--- a/include/ucore/utils.h
+++ b/include/ucore/utils.h
@@ -6,9 +6,8 @@
 
 //Gnerate a compiler error if the compile time
 //constant expression fails
-#define UC_STATIC_ASSERT(expr) \
-        enum { assert_static__ = 1/(expr) };
-
+#define UC_STATIC_ASSERT(expr)\
+    typedef int STATIC_ASSERT_FAILED[(expr) ? 1 : -1]
 
 //MAX of a and b
 #define UC_MAX(a,b) \
diff --git a/src/rate_limit.c b/src/rate_limit.c
index 2facdc1..a2ad6ef 100644
--- a/src/rate_limit.c
+++ b/src/rate_limit.c
@@ -32,9 +32,9 @@ static void uc_ratelimit_refill(struct RateLimit *r, long current_ts)
     //Find elapsed time
     diff_period = current_ts - r->last_refill_ts;
 
-    if (diff_period > r->period + 1) {
-        //help prevent overflow when calculating available_tickets below
-        diff_period = r->period + 1;
+    if (diff_period > r->period) {
+        //help prevent overflow when calculating available tickets below
+        diff_period = r->period;
     } else if (diff_period < 0) {
         //time went backwards, skip this round
         diff_period = 0;  
diff --git a/src/read_file.c b/src/read_file.c
index cf6c3f5..2bdb9e5 100644
--- a/src/read_file.c
+++ b/src/read_file.c
@@ -1,17 +1,17 @@
-#include    <stdlib.h>
-#include    <fcntl.h>
-#include    <unistd.h>
-#include    <errno.h>
-#include    <sys/types.h>
-#include    <sys/stat.h>
-#include   "ucore/read_file.h"
+#include <stdlib.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include "ucore/read_file.h"
 
 #define CHUNK_SZ 1024
 
 char *
-uc_read_file(const char *f, size_t *length, size_t max)
+uc_read_fd(int fd, size_t *length, size_t max)
 {
-    int fd;
     char *s = NULL;
     char *p;
     struct stat statb;
@@ -19,25 +19,26 @@ uc_read_file(const char *f, size_t *length, size_t max)
 
     *length = 0;
 
-    if ((fd = open(f, O_RDONLY)) == -1)
-        return NULL;
-
     if (fstat(fd, &statb) == -1) {
         goto out_close;
     }
 
     if ((statb.st_mode & S_IFMT) == S_IFREG) {
-        if ((size_t)statb.st_size > max) {
+        if (statb.st_size > (off_t)max) {
             errno = EMSGSIZE;
             goto out_close;
         }
-        alloc_sz = (size_t) statb.st_size + 1; // + 1 to avoid one realloc
-        s = malloc((size_t) alloc_sz + 1); //+1 for nul terminator
+        if (statb.st_size > SSIZE_MAX) {
+            //otherwise we cannot detect the return value of read()
+            alloc_sz = SSIZE_MAX;
+        } else {
+            alloc_sz = statb.st_size; 
+        }
     } else {
         alloc_sz = CHUNK_SZ;
-        s = malloc(alloc_sz + 1); //+1 for nul terminator
     }
 
+    s = malloc(alloc_sz + 1); //+1 for nul terminator
     if (s == NULL) {
         goto out_close;
     }
@@ -80,3 +81,15 @@ out_close:
     return s;
 }
 
+char *
+uc_read_file(const char *f, size_t *length, size_t max)
+{
+    int fd;
+
+    if ((fd = open(f, O_RDONLY)) == -1) {
+        *length = 0;
+        return NULL;
+    }
+
+    return uc_read_fd(fd, length, max);
+}
diff --git a/test/test_read_file.c b/test/test_read_file.c
index 5bef1f4..dcd8d68 100644
--- a/test/test_read_file.c
+++ b/test/test_read_file.c
@@ -13,6 +13,7 @@ START_TEST (test_read_file_non_existing_file)
     size_t len;
     int saved_errno;
 
+    errno = 0;
     content = uc_read_file("non existing file 123765", &len, 1000000000);
     saved_errno = errno;