Merge pull request #720 from civetweb/pr-get-info

Fix mg_get_{system|context|connection}_info()

src/civetweb.c

@@ -18920,44 +18920,51 @@ mg_check_feature(unsigned feature)
 }
 
 
-/* strcat with additional NULL check to avoid clang scan-build warning. */
-#define strcat0(a, b)                                                          \
-	{                                                                          \
-		if ((a != NULL) && (b != NULL)) {                                      \
-			strcat(a, b);                                                      \
-		}                                                                      \
+static size_t
+mg_str_append(char **dst, char *end, const char *src)
+{
+	size_t len = strlen(src);
+	if (*dst != end) {
+		/* Append src if enough space, or close dst. */
+		if ((size_t)(end - *dst) > len) {
+			strcpy(*dst, src);
+			*dst += len;
+		} else {
+			*dst = end;
+		}
 	}
+	return len;
+}
 
 
 /* Get system information. It can be printed or stored by the caller.
  * Return the size of available information. */
-static int
-mg_get_system_info_impl(char *buffer, int buflen)
+int
+mg_get_system_info(char *buffer, int buflen)
 {
-	char block[256];
-	int system_info_length = 0;
+	char *end, *append_eoobj = NULL, block[256];
+	size_t system_info_length = 0;
 
 #if defined(_WIN32)
-	const char *eol = "\r\n";
+	static const char eol[] = "\r\n", eoobj[] = "\r\n}\r\n";
 #else
-	const char *eol = "\n";
+	static const char eol[] = "\n", eoobj[] = "\n}\n";
 #endif
 
-	const char *eoobj = "}";
-	int reserved_len = (int)strlen(eoobj) + (int)strlen(eol);
-
 	if ((buffer == NULL) || (buflen < 1)) {
 		buflen = 0;
 	} else {
 		*buffer = 0;
 	}
-
-	mg_snprintf(NULL, NULL, block, sizeof(block), "{%s", eol);
-	system_info_length += (int)strlen(block);
-	if (system_info_length < buflen) {
-		strcat0(buffer, block);
+	end = buffer + buflen;
+	if (buflen > (int)(sizeof(eoobj) - 1)) {
+		/* has enough space to append eoobj */
+		append_eoobj = buffer;
+		end -= sizeof(eoobj) - 1;
 	}
 
+	system_info_length += mg_str_append(&buffer, end, "{");
+
 	/* Server version */
 	{
 		const char *version = mg_version();
@@ -18965,13 +18972,10 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"version\" : \"%s\",%s",
-		            version,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            "%s\"version\" : \"%s\"",
+		            eol,
+		            version);
+		system_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* System info */
@@ -19001,28 +19005,22 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"os\" : \"Windows %u.%u\",%s",
+		            ",%s\"os\" : \"Windows %u.%u\"",
+		            eol,
 		            (unsigned)dwMajorVersion,
-		            (unsigned)dwMinorVersion,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)dwMinorVersion);
+		system_info_length += mg_str_append(&buffer, end, block);
 
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"cpu\" : \"type %u, cores %u, mask %x\",%s",
+		            ",%s\"cpu\" : \"type %u, cores %u, mask %x\"",
+		            eol,
 		            (unsigned)si.wProcessorArchitecture,
 		            (unsigned)si.dwNumberOfProcessors,
-		            (unsigned)si.dwActiveProcessorMask,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)si.dwActiveProcessorMask);
+		system_info_length += mg_str_append(&buffer, end, block);
 #else
 		struct utsname name;
 		memset(&name, 0, sizeof(name));
@@ -19032,16 +19030,13 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"os\" : \"%s %s (%s) - %s\",%s",
+		            ",%s\"os\" : \"%s %s (%s) - %s\"",
+		            eol,
 		            name.sysname,
 		            name.version,
 		            name.release,
-		            name.machine,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            name.machine);
+		system_info_length += mg_str_append(&buffer, end, block);
 #endif
 	}
 
@@ -19051,8 +19046,9 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"features\" : %lu,%s"
-		            "\"feature_list\" : \"Server:%s%s%s%s%s%s%s%s%s\",%s",
+		            ",%s\"features\" : %lu"
+		            ",%s\"feature_list\" : \"Server:%s%s%s%s%s%s%s%s%s\"",
+		            eol,
 		            (unsigned long)mg_check_feature(0xFFFFFFFFu),
 		            eol,
 		            mg_check_feature(MG_FEATURES_FILES) ? " Files" : "",
@@ -19064,41 +19060,31 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            mg_check_feature(MG_FEATURES_LUA) ? " Lua" : "",
 		            mg_check_feature(MG_FEATURES_SSJS) ? " JavaScript" : "",
 		            mg_check_feature(MG_FEATURES_CACHE) ? " Cache" : "",
-		            mg_check_feature(MG_FEATURES_STATS) ? " Stats" : "",
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            mg_check_feature(MG_FEATURES_STATS) ? " Stats" : "");
+		system_info_length += mg_str_append(&buffer, end, block);
 
 #if defined(USE_LUA)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"lua_version\" : \"%u (%s)\",%s",
+		            ",%s\"lua_version\" : \"%u (%s)\"",
+		            eol,
 		            (unsigned)LUA_VERSION_NUM,
-		            LUA_RELEASE,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            LUA_RELEASE);
+		system_info_length += mg_str_append(&buffer, end, block);
 #endif
 #if defined(USE_DUKTAPE)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"javascript\" : \"Duktape %u.%u.%u\",%s",
+		            ",%s\"javascript\" : \"Duktape %u.%u.%u\"",
+		            eol,
 		            (unsigned)DUK_VERSION / 10000,
 		            ((unsigned)DUK_VERSION / 100) % 100,
-		            (unsigned)DUK_VERSION % 100,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)DUK_VERSION % 100);
+		system_info_length += mg_str_append(&buffer, end, block);
 #endif
 	}
 
@@ -19115,9 +19101,9 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"build\" : \"%s\",%s",
-		            __DATE__,
-		            eol);
+		            ",%s\"build\" : \"%s\"",
+		            eol,
+		            __DATE__);
 
 #if defined(GCC_DIAGNOSTIC)
 #if GCC_VERSION >= 40900
@@ -19125,10 +19111,7 @@ mg_get_system_info_impl(char *buffer, int buflen)
 #endif
 #endif
 
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		system_info_length += mg_str_append(&buffer, end, block);
 	}
 
 
@@ -19140,128 +19123,98 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"MSC: %u (%u)\",%s",
+		            ",%s\"compiler\" : \"MSC: %u (%u)\"",
+		            eol,
 		            (unsigned)_MSC_VER,
-		            (unsigned)_MSC_FULL_VER,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)_MSC_FULL_VER);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__MINGW64__)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"MinGW64: %u.%u\",%s",
+		            ",%s\"compiler\" : \"MinGW64: %u.%u\"",
+		            eol,
 		            (unsigned)__MINGW64_VERSION_MAJOR,
-		            (unsigned)__MINGW64_VERSION_MINOR,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)__MINGW64_VERSION_MINOR);
+		system_info_length += mg_str_append(&buffer, end, block);
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"MinGW32: %u.%u\",%s",
+		            ",%s\"compiler\" : \"MinGW32: %u.%u\"",
+		            eol,
 		            (unsigned)__MINGW32_MAJOR_VERSION,
-		            (unsigned)__MINGW32_MINOR_VERSION,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)__MINGW32_MINOR_VERSION);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__MINGW32__)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"MinGW32: %u.%u\",%s",
+		            ",%s\"compiler\" : \"MinGW32: %u.%u\"",
+		            eol,
 		            (unsigned)__MINGW32_MAJOR_VERSION,
-		            (unsigned)__MINGW32_MINOR_VERSION,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)__MINGW32_MINOR_VERSION);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__clang__)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"clang: %u.%u.%u (%s)\",%s",
+		            ",%s\"compiler\" : \"clang: %u.%u.%u (%s)\"",
+		            eol,
 		            __clang_major__,
 		            __clang_minor__,
 		            __clang_patchlevel__,
-		            __clang_version__,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            __clang_version__);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__GNUC__)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"gcc: %u.%u.%u\",%s",
+		            ",%s\"compiler\" : \"gcc: %u.%u.%u\"",
+		            eol,
 		            (unsigned)__GNUC__,
 		            (unsigned)__GNUC_MINOR__,
-		            (unsigned)__GNUC_PATCHLEVEL__,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)__GNUC_PATCHLEVEL__);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__INTEL_COMPILER)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"Intel C/C++: %u\",%s",
-		            (unsigned)__INTEL_COMPILER,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            ",%s\"compiler\" : \"Intel C/C++: %u\"",
+		            eol,
+		            (unsigned)__INTEL_COMPILER);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__BORLANDC__)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"Borland C: 0x%x\",%s",
-		            (unsigned)__BORLANDC__,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            ",%s\"compiler\" : \"Borland C: 0x%x\"",
+		            eol,
+		            (unsigned)__BORLANDC__);
+		system_info_length += mg_str_append(&buffer, end, block);
 #elif defined(__SUNPRO_C)
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"Solaris: 0x%x\",%s",
-		            (unsigned)__SUNPRO_C,
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            ",%s\"compiler\" : \"Solaris: 0x%x\"",
+		            eol,
+		            (unsigned)__SUNPRO_C);
+		system_info_length += mg_str_append(&buffer, end, block);
 #else
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"compiler\" : \"other\",%s",
+		            ",%s\"compiler\" : \"other\"",
 		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		system_info_length += mg_str_append(&buffer, end, block);
 #endif
 	}
 
@@ -19272,9 +19225,10 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"data_model\" : \"int:%u/%u/%u/%u, float:%u/%u/%u, "
+		            ",%s\"data_model\" : \"int:%u/%u/%u/%u, float:%u/%u/%u, "
 		            "char:%u/%u, "
-		            "ptr:%u, size:%u, time:%u\"%s",
+		            "ptr:%u, size:%u, time:%u\"",
+		            eol,
 		            (unsigned)sizeof(short),
 		            (unsigned)sizeof(int),
 		            (unsigned)sizeof(long),
@@ -19286,84 +19240,70 @@ mg_get_system_info_impl(char *buffer, int buflen)
 		            (unsigned)sizeof(wchar_t),
 		            (unsigned)sizeof(void *),
 		            (unsigned)sizeof(size_t),
-		            (unsigned)sizeof(time_t),
-		            eol);
-		system_info_length += (int)strlen(block);
-		if (system_info_length < buflen) {
-			strcat0(buffer, block);
-		}
+		            (unsigned)sizeof(time_t));
+		system_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Terminate string */
-	if ((buflen > 0) && buffer && buffer[0]) {
-		if (system_info_length < buflen) {
-			strcat0(buffer, eoobj);
-			strcat0(buffer, eol);
-		}
+	if (append_eoobj) {
+		strcat(append_eoobj, eoobj);
 	}
-	system_info_length += reserved_len;
+	system_info_length += sizeof(eoobj) - 1;
 
-	return system_info_length;
+	return (int)system_info_length;
 }
 
 
-#if defined(USE_SERVER_STATS)
 /* Get context information. It can be printed or stored by the caller.
  * Return the size of available information. */
-static int
-mg_get_context_info_impl(const struct mg_context *ctx, char *buffer, int buflen)
-
+int
+mg_get_context_info(const struct mg_context *ctx, char *buffer, int buflen)
 {
-	char block[256];
-	int context_info_length = 0;
+#if defined(USE_SERVER_STATS)
+	char *end, *append_eoobj = NULL, block[256];
+	size_t context_info_length = 0;
 
 #if defined(_WIN32)
-	const char *eol = "\r\n";
+	static const char eol[] = "\r\n", eoobj[] = "\r\n}\r\n";
 #else
-	const char *eol = "\n";
+	static const char eol[] = "\n", eoobj[] = "\n}\n";
 #endif
 	struct mg_memory_stat *ms = get_memory_stat((struct mg_context *)ctx);
 
-	const char *eoobj = "}";
-	int reserved_len = (int)strlen(eoobj) + (int)strlen(eol);
-
 	if ((buffer == NULL) || (buflen < 1)) {
 		buflen = 0;
 	} else {
 		*buffer = 0;
 	}
-
-	mg_snprintf(NULL, NULL, block, sizeof(block), "{%s", eol);
-	context_info_length += (int)strlen(block);
-	if (context_info_length < buflen) {
-		strcat0(buffer, block);
+	end = buffer + buflen;
+	if (buflen > (int)(sizeof(eoobj) - 1)) {
+		/* has enough space to append eoobj */
+		append_eoobj = buffer;
+		end -= sizeof(eoobj) - 1;
 	}
 
+	context_info_length += mg_str_append(&buffer, end, "{");
+
 	if (ms) { /* <-- should be always true */
 		/* Memory information */
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"memory\" : {%s"
+		            "%s\"memory\" : {%s"
 		            "\"blocks\" : %i,%s"
 		            "\"used\" : %" INT64_FMT ",%s"
 		            "\"maxUsed\" : %" INT64_FMT "%s"
-		            "}%s%s",
+		            "}",
+		            eol,
 		            eol,
 		            ms->blockCount,
 		            eol,
 		            ms->totalMemUsed,
 		            eol,
 		            ms->maxMemUsed,
-		            eol,
-		            (ctx ? "," : ""),
 		            eol);
-
-		context_info_length += (int)strlen(block);
-		if (context_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		context_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	if (ctx) {
@@ -19379,63 +19319,51 @@ mg_get_context_info_impl(const struct mg_context *ctx, char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"connections\" : {%s"
+		            ",%s\"connections\" : {%s"
 		            "\"active\" : %i,%s"
 		            "\"maxActive\" : %i,%s"
 		            "\"total\" : %" INT64_FMT "%s"
-		            "},%s",
+		            "}",
+		            eol,
 		            eol,
 		            ctx->active_connections,
 		            eol,
 		            ctx->max_connections,
 		            eol,
 		            ctx->total_connections,
-		            eol,
 		            eol);
-
-		context_info_length += (int)strlen(block);
-		if (context_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		context_info_length += mg_str_append(&buffer, end, block);
 
 		/* Requests information */
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"requests\" : {%s"
+		            ",%s\"requests\" : {%s"
 		            "\"total\" : %" INT64_FMT "%s"
-		            "},%s",
+		            "}",
 		            eol,
-		            ctx->total_requests,
 		            eol,
+		            ctx->total_requests,
 		            eol);
-
-		context_info_length += (int)strlen(block);
-		if (context_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		context_info_length += mg_str_append(&buffer, end, block);
 
 		/* Data information */
 		mg_snprintf(NULL,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"data\" : {%s"
-		            "\"read\" : %" INT64_FMT "%s,"
+		            ",%s\"data\" : {%s"
+		            "\"read\" : %" INT64_FMT ",%s"
 		            "\"written\" : %" INT64_FMT "%s"
-		            "},%s",
+		            "}",
+		            eol,
 		            eol,
 		            ctx->total_data_read,
 		            eol,
 		            ctx->total_data_written,
-		            eol,
 		            eol);
-
-		context_info_length += (int)strlen(block);
-		if (context_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		context_info_length += mg_str_append(&buffer, end, block);
 
 		/* Execution time information */
 		gmt_time_string(start_time_str,
@@ -19447,70 +19375,72 @@ mg_get_context_info_impl(const struct mg_context *ctx, char *buffer, int buflen)
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"time\" : {%s"
+		            ",%s\"time\" : {%s"
 		            "\"uptime\" : %.0f,%s"
 		            "\"start\" : \"%s\",%s"
 		            "\"now\" : \"%s\"%s"
-		            "}%s",
+		            "}",
+		            eol,
 		            eol,
 		            difftime(now, start_time),
 		            eol,
 		            start_time_str,
 		            eol,
 		            now_str,
-		            eol,
 		            eol);
-
-		context_info_length += (int)strlen(block);
-		if (context_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		context_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Terminate string */
-	if ((buflen > 0) && buffer && buffer[0]) {
-		if (context_info_length < buflen) {
-			strcat0(buffer, eoobj);
-			strcat0(buffer, eol);
-		}
+	if (append_eoobj) {
+		strcat(append_eoobj, eoobj);
 	}
-	context_info_length += reserved_len;
+	context_info_length += sizeof(eoobj) - 1;
 
-	return context_info_length;
-}
+	return (int)context_info_length;
+#else
+	(void)ctx;
+	if ((buffer != NULL) && (buflen > 0)) {
+		*buffer = 0;
+	}
+	return 0;
 #endif
+}
 
 
 #if defined(MG_EXPERIMENTAL_INTERFACES)
 /* Get connection information. It can be printed or stored by the caller.
  * Return the size of available information. */
-static int
-mg_get_connection_info_impl(const struct mg_context *ctx,
-                            int idx,
-                            char *buffer,
-                            int buflen)
+int
+mg_get_connection_info(const struct mg_context *ctx,
+                       int idx,
+                       char *buffer,
+                       int buflen)
 {
 	const struct mg_connection *conn;
 	const struct mg_request_info *ri;
-	char block[256];
-	int connection_info_length = 0;
+	char *end, *append_eoobj = NULL, block[256];
+	size_t connection_info_length = 0;
 	int state = 0;
 	const char *state_str = "unknown";
 
 #if defined(_WIN32)
-	const char *eol = "\r\n";
+	static const char eol[] = "\r\n", eoobj[] = "\r\n}\r\n";
 #else
-	const char *eol = "\n";
+	static const char eol[] = "\n", eoobj[] = "\n}\n";
 #endif
 
-	const char *eoobj = "}";
-	int reserved_len = (int)strlen(eoobj) + (int)strlen(eol);
-
 	if ((buffer == NULL) || (buflen < 1)) {
 		buflen = 0;
 	} else {
 		*buffer = 0;
 	}
+	end = buffer + buflen;
+	if (buflen > (int)(sizeof(eoobj) - 1)) {
+		/* has enough space to append eoobj */
+		append_eoobj = buffer;
+		end -= sizeof(eoobj) - 1;
+	}
 
 	if ((ctx == NULL) || (idx < 0)) {
 		/* Parameter error */
@@ -19527,11 +19457,7 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 	conn = (ctx->worker_connections) + idx;
 
 	/* Initialize output string */
-	mg_snprintf(NULL, NULL, block, sizeof(block), "{%s", eol);
-	connection_info_length += (int)strlen(block);
-	if (connection_info_length < buflen) {
-		strcat0(buffer, block);
-	}
+	connection_info_length += mg_str_append(&buffer, end, "{");
 
 	/* Init variables */
 	ri = &(conn->request_info);
@@ -19580,14 +19506,15 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"connection\" : {%s"
+		            "%s\"connection\" : {%s"
 		            "\"remote\" : {%s"
 		            "\"protocol\" : \"%s\",%s"
 		            "\"addr\" : \"%s\",%s"
 		            "\"port\" : %u%s"
 		            "},%s"
 		            "\"handled_requests\" : %u%s"
-		            "},%s",
+		            "}",
+		            eol,
 		            eol,
 		            eol,
 		            get_proto_name(conn),
@@ -19598,13 +19525,8 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            eol,
 		            eol,
 		            conn->handled_requests,
-		            eol,
 		            eol);
-
-		connection_info_length += (int)strlen(block);
-		if (connection_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		connection_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Request info */
@@ -19613,11 +19535,13 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"request_info\" : {%s"
+		            "%s%s\"request_info\" : {%s"
 		            "\"method\" : \"%s\",%s"
 		            "\"uri\" : \"%s\",%s"
 		            "\"query\" : %s%s%s%s"
-		            "},%s",
+		            "}",
+		            (connection_info_length > 1 ? "," : ""),
+		            eol,
 		            eol,
 		            ri->request_method,
 		            eol,
@@ -19626,13 +19550,8 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            ri->query_string ? "\"" : "",
 		            ri->query_string ? ri->query_string : "null",
 		            ri->query_string ? "\"" : "",
-		            eol,
 		            eol);
-
-		connection_info_length += (int)strlen(block);
-		if (connection_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		connection_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Execution time information */
@@ -19651,24 +19570,21 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"time\" : {%s"
+		            "%s%s\"time\" : {%s"
 		            "\"uptime\" : %.0f,%s"
 		            "\"start\" : \"%s\",%s"
 		            "\"now\" : \"%s\"%s"
-		            "},%s",
+		            "}",
+		            (connection_info_length > 1 ? "," : ""),
+		            eol,
 		            eol,
 		            difftime(now, start_time),
 		            eol,
 		            start_time_str,
 		            eol,
 		            now_str,
-		            eol,
 		            eol);
-
-		connection_info_length += (int)strlen(block);
-		if (connection_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		connection_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Remote user name */
@@ -19677,18 +19593,15 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"user\" : {%s"
+		            "%s%s\"user\" : {%s"
 		            "\"name\" : \"%s\",%s"
-		            "},%s",
+		            "}",
+		            (connection_info_length > 1 ? "," : ""),
 		            eol,
-		            ri->remote_user,
 		            eol,
+		            ri->remote_user,
 		            eol);
-
-		connection_info_length += (int)strlen(block);
-		if (connection_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		connection_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* Data block */
@@ -19697,21 +19610,18 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 		            NULL,
 		            block,
 		            sizeof(block),
-		            "\"data\" : {%s"
+		            "%s%s\"data\" : {%s"
 		            "\"read\" : %" INT64_FMT ",%s"
 		            "\"written\" : %" INT64_FMT "%s"
-		            "},%s",
+		            "}",
+		            (connection_info_length > 1 ? "," : ""),
+		            eol,
 		            eol,
 		            conn->consumed_content,
 		            eol,
 		            conn->num_bytes_sent,
-		            eol,
 		            eol);
-
-		connection_info_length += (int)strlen(block);
-		if (connection_info_length + reserved_len < buflen) {
-			strcat0(buffer, block);
-		}
+		connection_info_length += mg_str_append(&buffer, end, block);
 	}
 
 	/* State */
@@ -19719,81 +19629,19 @@ mg_get_connection_info_impl(const struct mg_context *ctx,
 	            NULL,
 	            block,
 	            sizeof(block),
-	            "\"state\" : \"%s\"%s",
-	            state_str,
-	            eol);
-
-	connection_info_length += (int)strlen(block);
-	if (connection_info_length + reserved_len < buflen) {
-		strcat0(buffer, block);
-	}
+	            "%s%s\"state\" : \"%s\"",
+	            (connection_info_length > 1 ? "," : ""),
+	            eol,
+	            state_str);
+	connection_info_length += mg_str_append(&buffer, end, block);
 
 	/* Terminate string */
-	if ((buflen > 0) && buffer && buffer[0]) {
-		if (connection_info_length < buflen) {
-			strcat0(buffer, eoobj);
-			strcat0(buffer, eol);
-		}
+	if (append_eoobj) {
+		strcat(append_eoobj, eoobj);
 	}
-	connection_info_length += reserved_len;
-
-	return connection_info_length;
-}
-#endif
-
+	connection_info_length += sizeof(eoobj) - 1;
 
-/* Get system information. It can be printed or stored by the caller.
- * Return the size of available information. */
-int
-mg_get_system_info(char *buffer, int buflen)
-{
-	if ((buffer == NULL) || (buflen < 1)) {
-		return mg_get_system_info_impl(NULL, 0);
-	} else {
-		/* Reset buffer, so we can always use strcat. */
-		buffer[0] = 0;
-		return mg_get_system_info_impl(buffer, buflen);
-	}
-}
-
-
-/* Get context information. It can be printed or stored by the caller.
- * Return the size of available information. */
-int
-mg_get_context_info(const struct mg_context *ctx, char *buffer, int buflen)
-{
-#if defined(USE_SERVER_STATS)
-	if ((buffer == NULL) || (buflen < 1)) {
-		return mg_get_context_info_impl(ctx, NULL, 0);
-	} else {
-		/* Reset buffer, so we can always use strcat. */
-		buffer[0] = 0;
-		return mg_get_context_info_impl(ctx, buffer, buflen);
-	}
-#else
-	(void)ctx;
-	if ((buffer != NULL) && (buflen > 0)) {
-		buffer[0] = 0;
-	}
-	return 0;
-#endif
-}
-
-
-#if defined(MG_EXPERIMENTAL_INTERFACES)
-int
-mg_get_connection_info(const struct mg_context *ctx,
-                       int idx,
-                       char *buffer,
-                       int buflen)
-{
-	if ((buffer == NULL) || (buflen < 1)) {
-		return mg_get_connection_info_impl(ctx, idx, NULL, 0);
-	} else {
-		/* Reset buffer, so we can always use strcat. */
-		buffer[0] = 0;
-		return mg_get_connection_info_impl(ctx, idx, buffer, buflen);
-	}
+	return (int)connection_info_length;
 }
 #endif