On 09/06/2012 11:46 AM, Stephen Warren wrote: > 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.
No, you make a good point. Thanks! -- Tom _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot