execl() in clear_screen needs a NULL terminator. #55
Description
On startup, cpm prints:
Usage: clear [options]
Options:
-T TERM use this instead of $TERM
-V print curses-version
-x do not try to clear scrollback
This is because it calls execl("/usr/bin/clear", "clear") instead of execl("/usr/bin/clear", "clear", NULL). Forgetting the NULL terminator for the argument list causes execl to pass additional garbage arguments from registers or stack.