Added --version flag to init and updated manual page.

doc/Changelog

@@ -5,6 +5,8 @@ sysvinit (2.91) UNRELEASED; urgency=low
     * Adjusted order of compile flags to make it easier for downstream
       to adjust optimization level. Patch provided by Matias Fonzo.
       Can now set optimization level in CFLAGS variable.
+    * Added --version command line flag to display current version info.
+      Updated manual page for init.8 to match.
 
 sysvinit (2.90) world; urgency=low
 

man/init.8

@@ -32,6 +32,9 @@ init, telinit \- process control initialization
 [ \fB\-z\fP \fIxxx\fP ]
 .RB [ " 0123456Ss " ]
 .br
+.B /sbin/init
+.RB [ " --version " ]
+.br
 .B /sbin/telinit
 [ \fB\-t\fP \fISECONDS\fP ]
 .RB [ " 0123456sSQqabcUu " ]
@@ -247,6 +250,12 @@ line a bit, so that it takes some more space on the stack. \fBInit\fP
 can then manipulate the command line so that \fBps\fP(1) shows
 the current runlevel.
 .PP
+.TP 0.5i
+.BI "--version "
+This argument, when used on its own, displays the current version of init
+to the console/stdout. It is a quick way to determine which init software and
+version is being used.
+.PP
 .SH INTERFACE
 Init listens on a \fIfifo\fP in /dev, \fI/run/initctl\fP, for messages.
 \fBTelinit\fP uses this to communicate with init. The interface is not

src/init.c

@@ -3000,6 +3000,12 @@ int main(int argc, char **argv)
 	else
   		p = argv[0];
 
+        if ( (argc == 2) && (! strcmp(argv[1], "--version") ) )
+        {
+           printf("SysV init version: %s\n\n", VERSION);
+           exit(0);
+        }
+
 	/* Common umask */
 	umask(umask(077) | 022);