On 09/06/2012 11:12 AM, Tom Rini wrote: > On Wed, Sep 05, 2012 at 08:38:26PM -0600, Stephen Warren wrote: >> On 09/05/2012 05:51 PM, Rob Herring wrote: >>> On 09/05/2012 05:03 PM, Stephen Warren wrote: >>>> From: Stephen Warren <swar...@nvidia.com> >>>> >>>> This implements the following: >>>> >>>> part uuid mmc 0:1 >>>> -> print partition UUID >>>> part uuid mmc 0:1 uuid >>>> -> set environment variable to partition UUID >>> >>> What's the reason to not always both print out and set the uuid env var? >>> >>> Perhaps the env name should be partuuid or part_uuid as you could have >>> uuid's for other purposes? >> >> The idea is that if you're running the command interactively, you won't >> pass a variable name on the command-line, so the command will print out >> the UUID for you to read. In this case, it's pointless to set any >> environment variable. >> >> However, if you're writing a script, you want to capture the UUID into >> an environment variable, and it's quite unlikely you want to litter >> stdout with that content too. Hence, either-or, not both. > > Do other commands have a "I'm being scripted, probably, don't stdout" > and "I'm being interactive, use stdout" distinction like this? IMHO, > always printing out makes sense so you can "see" that your script is > working as you expect.
In general, as a script writer, yes you do have the ability to choose. Typically, I'd write: part uuid .... vs. var=`part uuid ....` in order to control this. However, U-Boot's shell doesn't support backticks. As a script writer, I certainly desire the ability to control what commands spam to the console, and really don't think it's useful to print the UUID from a script (does the user really care, and any script developer can just echo it for debugging if they need it). I'm not aware of other U-Boot commands whose purpose it is to set environment variables, so can't really compare. Still, if you're insistent on this point, I can change the code to always print, and optionally write an environment variable. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot