From owner-freebsd-questions  Tue Nov  4 21:20:43 1997
Return-Path: <owner-freebsd-questions>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id VAA12789
          for questions-outgoing; Tue, 4 Nov 1997 21:20:43 -0800 (PST)
          (envelope-from owner-freebsd-questions)
Received: from luke.cpl.net (luke.cpl.net [207.67.172.194])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id VAA12784
          for <questions@FreeBSD.ORG>; Tue, 4 Nov 1997 21:20:39 -0800 (PST)
          (envelope-from shawn@luke.cpl.net)
Received: from localhost (shawn@localhost) by luke.cpl.net (8.8.7/8.6.12) with SMTP id VAA05507; Tue, 4 Nov 1997 21:17:44 -0800 (PST)
Date: Tue, 4 Nov 1997 21:17:43 -0800 (PST)
From: Shawn Ramsey <shawn@luke.cpl.net>
To: yama-ko <yama-ko@mx2.nisiq.net>
cc: questions@FreeBSD.ORG
Subject: Re: question
In-Reply-To: <199711050438.NAA27590@mx2.nisiq.net>
Message-ID: <Pine.BSF.3.95.971104211646.5497A-100000@luke.cpl.net>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-questions@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

> I can compile programs with C , but I cannot execute them . Why ?
> 
> <For example>
> %gcc sample.c
> %ls
> a.out    sample.c
> %a.out
> a.out : cannot found command
> %

Because the directory you are trying to execute it in is not in your path.
Try ./a.out.