new file mode 100644
--- /dev/null
+++ b/src/core/ngx_log.c
@@ -0,0 +1,116 @@
+
+/*
+   TODO: log pid and tid
+*/
+
+/*
+   "[time as ctime()] [alert] 412:3 (32)Broken pipe: anything"
+
+   "[time as ctime()] [alert] (32)Broken pipe: anything"
+   "[time as ctime()] [alert] anything"
+*/
+
+#include <ngx_config.h>
+#include <ngx_errno.h>
+#include <ngx_time.h>
+#include <ngx_string.h>
+#include <ngx_log.h>
+
+
+static const char *err_levels[] = {
+    "emerg", "alert", "crit", "error", "warn", "notice", "info", "debug"
+};
+
+#if (HAVE_VARIADIC_MACROS)
+void ngx_log_error_core(int level, ngx_log_t *log, ngx_err_t err,
+                        const char *fmt, ...)
+#else
+void ngx_log_error_core(int level, ngx_log_t *log, ngx_err_t err,
+                        const char *fmt, va_list args)
+#endif
+{
+    char       errstr[MAX_ERROR_STR];
+    ngx_tm_t   tm;
+    size_t     len;
+#if (HAVE_VARIADIC_MACROS)
+    va_list    args;
+#endif
+
+    ngx_localtime(&tm);
+    len = ngx_snprintf(errstr, sizeof(errstr), "%02d:%02d:%02d",
+                       tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec);
+
+    if (err) {
+        if ((unsigned) err < 0x80000000)
+            len += ngx_snprintf(errstr + len, sizeof(errstr) - len - 1,
+                            " [%s] (%d)",
+                            err_levels[level], err);
+            len += ngx_snprintf(errstr + len, sizeof(errstr) - len - 1,
+                            " [%s] (%X)",
+                            err_levels[level], err);
+
+        len += ngx_strerror_r(err, errstr + len, sizeof(errstr) - len - 1);
+        if (len < sizeof(errstr) - 2) {
+            errstr[len++] = ':';
+            errstr[len++] = ' ';
+        } else {
+            len = sizeof(errstr) - 2;
+        }
+
+    } else {
+        len += ngx_snprintf(errstr + len, sizeof(errstr) - len - 1,
+                            " [%s] ", err_levels[level]);
+    }
+
+#if (HAVE_VARIADIC_MACROS)
+    va_start(args, fmt);
+    len += ngx_vsnprintf(errstr + len, sizeof(errstr) - len - 1, fmt, args);
+    va_end(args);
+#else
+    len += ngx_vsnprintf(errstr + len, sizeof(errstr) - len - 1, fmt, args);
+#endif
+
+    if (len > sizeof(errstr) - 2)
+        len = sizeof(errstr) - 2;
+    errstr[len] = '\n';
+    errstr[len + 1] = '\0';
+
+    fputs(errstr, stderr);
+
+    if (level == NGX_LOG_EMERG)
+        exit(1);
+}
+
+#if !(HAVE_VARIADIC_MACROS)
+
+void ngx_log_error(int level, ngx_log_t *log, ngx_err_t err,
+                   const char *fmt, ...)
+{
+    va_list    args;
+
+    if (log->log_level >= level) {
+        va_start(args, fmt);
+        ngx_log_error_core(level, log, err, fmt, args);
+        va_end(args);
+    }
+}
+
+void ngx_log_debug_core(ngx_log_t *log, const char *fmt, ...)
+{
+    va_list    args;
+
+    va_start(args, fmt);
+    ngx_log_error_core(NGX_LOG_DEBUG, log, 0, fmt, args);
+    va_end(args);
+}
+
+void ngx_assert_core(ngx_log_t *log, const char *fmt, ...)
+{
+    va_list    args;
+
+    va_start(args, fmt);
+    ngx_log_error_core(NGX_LOG_ALERT, log, 0, fmt, args);
+    va_end(args);
+}
+
+#endif