in reply to Re: Working with Binary Numbers
in thread Working with Binary Numbers

It seems to me that you are abusing a bug in glob

After expanding the pattern it should check that the entries actually exist on the file system and return only those that do.

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Re^3: Working with Binary Numbers
by blokhead (Monsignor) on Sep 25, 2007 at 14:30 UTC
    This rule does not apply to {x,y,z} alternations in the glob pattern. The documentation I could find isn't great on this point, and its language is generally in terms of filenames. But I'm 99% sure it's not a bug. I've seen tons of uses of glob in this way on PM!

    BTW, the same behavior should happen in your shell (though it may be a different glob under the hood). 

    $ ls {x,y,z}
ls: x: No such file or directory
ls: y: No such file or directory
ls: z: No such file or directory

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    First, glob expands {...} and then it checks the filesystem to expand * and ? and the resulting pattern(s). 
    $ ls *{p,q,r}
ls: *p: No such file or directory
ls: *q: No such file or directory
ls: *r: No such file or directory

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    blokhead

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      That's what bash docs says about the matter:
      Read more... (5 kB)
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        Just to be clearer, if you read the first two sentences of the long section you quoted, it answers your original concern:

        Brace expansion is a mechanism by which arbitrary strings may be generated. This mechanism is similar to pathname expansion, but the filenames generated need not exist.

        So, no, this is not a bug.

        - tye        

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        If bash had any bearing in the matter — glob is based on csh's expansion mechanism — it seems to me you just disproved yourself. "the filenames generated need not exist."

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