From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Date: Fri, 25 Sep 2020 14:59:16 +0200 Subject: [PATCH 0/3] add "call" command In-Reply-To: <20200925111942.4629-1-rasmus.villemoes@prevas.dk> References: <20200925111942.4629-1-rasmus.villemoes@prevas.dk> Message-ID: <4118329.1601038756@gemini.denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Rasmus, In message <20200925111942.4629-1-rasmus.villemoes@prevas.dk> you wrote: > This adds a way to call a "function" defined in the environment with > arguments. I.e., whereas > > run foo > > requires one to set the (shell or environment) variables referenced > from foo beforehand, with this one can instead do > > call foo arg1 arg2 arg3 > > and use $1... up to $9 in the definition of foo. $# is set so foo can > make decisions based on that, and ${3:-default} works as expected. This is definitely a useful idea. But... ...the current version of hush in U-Boot is old, has a number of known bugs and shortcomings, and I really recommend not to adding any new features to it, because that would makie an update to a more recent version even less likely. So the first step before such extensions should be to update hush. In that process (which might be more of a new port) one should consider the possibility of keeping a little more of the functionality - memory restrictins today are not so strict any more as they were when hush was originally added. One feature that would definitely be useful is command substitution. All this needs a bit of a long term maintainable concept. Quick hacking of the ancient code is not a good idea. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de God runs electromagnetics by wave theory on Monday, Wednesday, and Friday, and the Devil runs them by quantum theory on Tuesday, Thurs- day, and Saturday. -- William Bragg