1 files changed, 121 insertions, 0 deletions
diff --git a/src/common.h b/src/common.h
new file mode 100644
index 0000000..2f8ac86
--- /dev/null
+++ b/src/common.h
@@ -0,0 +1,121 @@
+/**
+ * Copyright © 2015  Mattias Andrée <maandree@member.fsf.org>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+
+
+/**
+ * Go to `fail` if a statement evaluates to non-zero.
+ * 
+ * @param  ...  The statement.
+ */
+#define t(...)  do { if (__VA_ARGS__) goto fail; } while (0)
+
+
+
+/**
+ * Defines the function `void usage(void)`
+ * that prints usage information.
+ * 
+ * @param  synopsis:const char*  The command's synopsis sans command name.
+ *                               `NULL` if there are not arguments.
+ */
+#define USAGE(synopsis)  \
+static void  \
+usage(void)  \
+{  \
+	fprintf(stderr, "usage: %s%s%s\n",  \
+	        strrchr(argv0, '/') ? (strrchr(argv0, '/') + 1) : argv0,  \
+	        (synopsis) ? " " : "", synopsis ? synopsis : "");  \
+	exit(2);  \
+}
+
+
+/**
+ * Declares `argv0` and its value to
+ * a specified string.
+ * 
+ * @param  name:sitrng literal  The name of the command.
+ */
+#define COMMAND(name)  \
+char *argv0 = name;
+
+
+/**
+ * Print usage and exit if there is any argument
+ * that is an option.
+ */
+#define NO_OPTIONS  \
+	int i;
+	if (!strcmp(argv[1], "--"))  \
+		argv++, argc--;  \
+	for (i = 1; i < argc; i++)  \
+		if (strchr("-", argv[i][0]))  \
+			usage()
+
+
+/**
+ * Construct a message from `argv`
+ * to send to the daemon.
+ */
+#define CONSTRUCT_MESSAGE  \
+	n = measure_array(argv + 1);  \
+	t (n ? !(msg = malloc(n)) : 0);  \
+	store_array(msg, argv + 1)
+
+
+/**
+ * Send message to daemon.
+ * 
+ * @param   cmd:enum command  Command type.
+ * @param   n:size_t          The length of the message, 0 if
+ *                            `msg` is `NULL` or NUL-terminated.
+ * @param   msg:char *        The message to send.
+ */
+#define SEND(type, n, msg)  \
+do {  \
+	if (send_command(type, n, msg)) {  \
+		t (errno);  \
+		free(msg);  \
+		return 3;  \
+	}
+} while (0)
+
+
+/**
+ * Exit the process with status indicating success.
+ * 
+ * Defined the label `fail`.
+ * 
+ * @param  msg  The message send to the daemon.
+ */
+#define END(msg)  \
+	free(msg);  \
+	return 0;  \
+fail:  \
+	perror(argv0);  \
+	free(msg);  \
+	return 1;
+