![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
diff --git a/src/utils/error.c b/src/utils/error.c
--- /dev/null
+++ b/src/utils/error.c
@@ -0,0 +1,283 @@
+/*
+ * SysDB - src/utils/error.c
+ * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "core/plugin.h"
+#include "utils/error.h"
+#include "utils/strbuf.h"
+
+#include <pthread.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <stdlib.h>
+
+/*
+ * private data types
+ */
+
+typedef struct {
+ int prio;
+ sdb_strbuf_t *msg;
+ _Bool logged;
+} sdb_error_ctx_t;
+#define SDB_ERROR_INIT { -1, NULL, 1 }
+
+/*
+ * private variables
+ */
+
+static sdb_error_ctx_t default_error_ctx = SDB_ERROR_INIT;
+
+static pthread_key_t error_ctx_key;
+static _Bool error_ctx_key_initialized = 0;
+
+/*
+ * private helper functions
+ */
+
+static void
+sdb_error_ctx_destructor(void *p)
+{
+ sdb_error_ctx_t *ctx = p;
+
+ if (! ctx)
+ return;
+
+ sdb_strbuf_destroy(ctx->msg);
+ free(ctx);
+} /* sdb_error_ctx_destructor */
+
+static void
+sdb_error_ctx_init(void)
+{
+ if (error_ctx_key_initialized)
+ return;
+
+ pthread_key_create(&error_ctx_key, sdb_error_ctx_destructor);
+ error_ctx_key_initialized = 1;
+} /* sdb_error_init */
+
+static sdb_error_ctx_t *
+sdb_error_ctx_create(void)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = malloc(sizeof(*ctx));
+ if (! ctx)
+ return NULL;
+
+ *ctx = default_error_ctx;
+ ctx->msg = sdb_strbuf_create(64);
+ if (! ctx->msg) {
+ free(ctx);
+ return NULL;
+ }
+
+ if (! error_ctx_key_initialized)
+ sdb_error_ctx_init();
+ pthread_setspecific(error_ctx_key, ctx);
+ return ctx;
+} /* sdb_error_ctx_create */
+
+static sdb_error_ctx_t *
+sdb_error_get_ctx(void)
+{
+ sdb_error_ctx_t *ctx;
+
+ if (! error_ctx_key_initialized)
+ sdb_error_ctx_init();
+ ctx = pthread_getspecific(error_ctx_key);
+
+ if (! ctx)
+ ctx = sdb_error_ctx_create();
+ if (! ctx)
+ return NULL;
+ return ctx;
+} /* sdb_error_get_ctx */
+
+static int
+sdb_error_vprintf(const char *fmt, va_list ap)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return -1;
+
+ ctx->logged = 0;
+ return (int)sdb_strbuf_vsprintf(ctx->msg, fmt, ap);
+} /* sdb_error_vprintf */
+
+static int
+sdb_error_vappend(const char *fmt, va_list ap)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return -1;
+
+ ctx->logged = 0;
+ return (int)sdb_strbuf_vappend(ctx->msg, fmt, ap);
+} /* sdb_error_vappend */
+
+static int
+sdb_do_log(int prio)
+{
+ sdb_error_ctx_t *ctx;
+ int ret;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return -1;
+
+ if (prio >= 0)
+ ctx->prio = prio;
+
+ if (ctx->logged)
+ return 0;
+
+ ret = sdb_plugin_log(prio, sdb_strbuf_string(ctx->msg));
+ ctx->logged = 1;
+ return ret;
+} /* sdb_do_log */
+
+/*
+ * public API
+ */
+
+int
+sdb_log(int prio, const char *fmt, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = sdb_error_vprintf(fmt, ap);
+ va_end(ap);
+
+ if (ret > 0)
+ sdb_do_log(prio);
+ return ret;
+} /* sdb_log */
+
+int
+sdb_error_set(const char *fmt, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = sdb_error_vprintf(fmt, ap);
+ va_end(ap);
+
+ return ret;
+} /* sdb_error_set */
+
+int
+sdb_error_append(const char *fmt, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = sdb_error_vappend(fmt, ap);
+ va_end(ap);
+
+ return ret;
+} /* sdb_error_append */
+
+int
+sdb_error_chomp(void)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return -1;
+
+ sdb_strbuf_chomp(ctx->msg);
+ return 0;
+} /* sdb_error_chomp */
+
+int
+sdb_error_log(int prio)
+{
+ return sdb_do_log(prio);
+} /* sdb_error_log */
+
+const char *
+sdb_error_get(void)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return "success";
+ return sdb_strbuf_string(ctx->msg);
+} /* sdb_error_get */
+
+int
+sdb_error_get_prio(void)
+{
+ sdb_error_ctx_t *ctx;
+
+ ctx = sdb_error_get_ctx();
+ if (! ctx)
+ return -1;
+ return ctx->prio;
+} /* sdb_error_get_prio */
+
+char *
+sdb_strerror(int errnum, char *strerrbuf, size_t buflen)
+{
+#if STRERROR_R_CHAR_P
+ {
+ char *tmp = strerror_r(errnum, strerrbuf, buflen);
+ if (*strerrbuf = '\0') {
+ if (tmp && (tmp != strerrbuf) && (*tmp != '\0'))
+ strncpy(strerrbuf, tmp, buflen);
+ else
+ snprintf(strerrbuf, buflen, "unknown error #%i "
+ "(strerror_r(3) did not return an error message)",
+ errnum);
+ }
+ }
+#else
+ if (strerror_r(errnum, strerrbuf, buflen))
+ snprintf(strerrbuf, buflen, "unknown error #%i "
+ "(strerror_r(3) failed)", errnum);
+#endif
+
+ strerrbuf[buflen - 1] = '\0';
+ return strerrbuf;
+} /* sdb_strerror */
+
+/* vim: set tw=78 sw=4 ts=4 noexpandtab : */
+