From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Erickson Date: Wed, 07 May 2008 06:56:04 -0700 Subject: [U-Boot-Users] [PATCH] Propagate Error Status to the Shell on fw_printenv Errors In-Reply-To: <20080507071007.0818A2477F@gemini.denx.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 5/7/08 12:10 AM, Wolfgang Denk wrote: > In message <87myn2ehqm.fsf@denx.de> you wrote: >> >>> root at kilauea# fw_printenv -n hostname ipaddr >>> ## Error: `-n' option requires exactly one argument >>> root at kilauea# echo $? >>> 1 >> >> But I don't understand what the purpose of the "-n" option is? > > The purpose seems clear to me - print the value of a variable without > the name. This can be useful in shell scripts, for example when you > want to do something like > > $ ipaddr=`fw_printenv -n ipaddr` > > However, the addition of this feature is undocumented (not mentioned > in the commit message), and I don;t see why we should restrict it to a > single variable - it may be useful to print several values here, too, > for example like that: > > $ set `fw_printenv -n netdev ipaddr netmask` > $ ifconfig $1 $2 netmask $3 > > [Well, I know that's a bad example because it's missing all error > checking, but you get the idea.] The "-n" option is not a new feature. It already existed in the code prior to my changes. Per my comments to Markus in a follow-up to his post, I am happy to evaluate extending the "-n" functionality, but would like to do so as a separate effort to the submitted patch which, I believe, stands on its own. Regards, Grant