sx: drop dependency on openssl

Turns out openssl rand would obnoxiously create a HOME/.rnd dotfile
unless told otherwise with the RANDFILE environment.  Unfortunately
this neither options are compelling and neither can openssl rand be
told to not write this file.

Instead I'm going to use /dev/urandom which appears to be available
on practically every UNIX.

This commit also tidies up the timeout kill logic to better express
what I am doing.

README

@@ -37,7 +37,7 @@ REQUIRES
 
   * Xorg
   * xauth
-  * openssl (used to generate the MIT-MAGIC-COOKIE-1 value)
+  * /dev/urandom
 
 INSTALL
 

sx

@@ -1,7 +1,7 @@
 #!/bin/sh --
 # sx - start an xserver
 
-# requires openssl xauth Xorg
+# requires xauth Xorg
 
 # I'm willing to take advantage of errexit for this script as roughly 85% of
 # the error checking would just be exiting on command failure.
@@ -18,18 +18,17 @@ cleanup() {
         # Send SIGKILL after 10 seconds if the xserver is taking too long to
         # terminate.
         interval=10
-        until [ "$interval" -le 0 ]; do
-            if ! kill -0 "$1"; then
-                break
-            fi
-            sleep 1
-            interval=$((interval - 1))
-        done
-
-        # Make sure that the PID still refers to an Xorg process
-        if test "$interval" -le 0 -a "$(ps -o comm= "$1")" = Xorg; then
+        while kill -0 "$1"; do
+            if [ "$interval" -le 0 ]; then
+                # Make sure the PID is still (probably) an Xorg process.
+                if [ "$(ps -o comm= "$1")" = Xorg ]; then
                     kill -s KILL "$1"
                 fi
+                break
+            fi
+            interval=$((interval - 1))
+            sleep 1
+        done
     fi
 
     if ! stty "$stty"; then
@@ -55,7 +54,7 @@ touch "$XAUTHORITY"
 
 trap 'cleanup "$pid"' EXIT
 
-xauth add :"$tty" MIT-MAGIC-COOKIE-1 "$(openssl rand -hex 16)"
+xauth add :"$tty" MIT-MAGIC-COOKIE-1 "$(od -An -N16 -tx /dev/urandom | tr -d ' ')"
 
 # Xorg will check if SIGUSR1 was set to SIG_IGN in its environment and issue
 # its own SIGUSR1 back to the parent process when it is ready to accept
@@ -68,5 +67,4 @@ trap 'DISPLAY=:$tty "${@:-$cfgdir/sxrc}"' USR1
     trap '' USR1
     exec /usr/lib/xorg-server/Xorg :"$tty" -keeptty vt"$tty" -noreset -auth "$XAUTHORITY"
 ) & pid=$!
-
 wait