-const char *rrd_strerror(int err) {
- struct rrd_context *ctx = rrd_get_context();
- return strerror_r(err, ctx->lib_errstr, ctx->errlen);
+const char *rrd_strerror(
+ int err)
+{
+ rrd_context_t *ctx = rrd_get_context();
+ char *ret = "unknown error";
+
+ *ctx->lib_errstr = '\0';
+
+ /* Even though POSIX/XSI requires "strerror_r" to return an "int", some
+ * systems (e.g. the GNU libc) return a "char *" _and_ ignore the second
+ * argument ... -tokkee */
+#ifdef STRERROR_R_CHAR_P
+ ret = strerror_r(err, ctx->lib_errstr, sizeof(ctx->lib_errstr));
+ if ((! ret) || (*ret == '\0')) {
+ if (*ctx->lib_errstr != '\0')
+ ret = ctx->lib_errstr;
+ else {
+ /* according to the manpage this should not happen -
+ let's handle it somehow sanely anyway */
+ snprintf(ctx->lib_errstr, sizeof(ctx->lib_errstr),
+ "unknown error %i - strerror_r did not return anything",
+ err);
+ ctx->lib_errstr[sizeof(ctx->lib_errstr) - 1] = '\0';
+ ret = ctx->lib_errstr;
+ }
+ }
+#else /* ! STRERROR_R_CHAR_P */
+ if (strerror_r(err, ctx->lib_errstr, sizeof(ctx->lib_errstr))) {
+ snprintf(ctx->lib_errstr, sizeof(ctx->lib_errstr),
+ "unknown error %i - strerror_r returned with errno = %i",
+ err, errno);
+ ctx->lib_errstr[sizeof(ctx->lib_errstr) - 1] = '\0';
+ }
+ ret = ctx->lib_errstr;
+#endif
+ return ret;