Document the new options

man/i3.man

@@ -9,16 +9,28 @@ i3 - an improved dynamic, tiling window manager
 
 == SYNOPSIS
 
-i3 [-c configfile] [-a]
+i3 [-a] [-c configfile] [-C] [-d <loglevel>] [-v] [-V]
 
 == OPTIONS
 
--c::
-Specifies an alternate configuration file path
-
 -a::
 Disables autostart.
 
+-c::
+Specifies an alternate configuration file path.
+
+-C::
+Check the configuration file for validity and exit.
+
+-d::
+Specifies the debug loglevel. To see the most output, use -d all.
+
+-v::
+Display version number (and date of the last commit).
+
+-V::
+Be verbose.
+
 == DESCRIPTION
 
 === INTRODUCTION

src/mainx.c

@@ -198,13 +198,14 @@ int main(int argc, char *argv[], char *env[]) {
                                 /* DEPRECATED, ignored for the next 3 versions (3.e, 3.f, 3.g) */
                                 break;
                         default:
-                                fprintf(stderr, "Usage: %s [-c configfile] [-d loglevel] [-a] [-v] [-V]\n", argv[0]);
+                                fprintf(stderr, "Usage: %s [-c configfile] [-d loglevel] [-a] [-v] [-V] [-C]\n", argv[0]);
                                 fprintf(stderr, "\n");
                                 fprintf(stderr, "-a: disable autostart\n");
                                 fprintf(stderr, "-v: display version and exit\n");
                                 fprintf(stderr, "-V: enable verbose mode\n");
                                 fprintf(stderr, "-d <loglevel>: enable debug loglevel <loglevel>\n");
                                 fprintf(stderr, "-c <configfile>: use the provided configfile instead\n");
+                                fprintf(stderr, "-C: check configuration file and exit\n");
                                 exit(EXIT_FAILURE);
                 }
         }