Control: tags -1 + upstream

El 16/09/19 a las 12:09, Trent W. Buck escribió:
> Package: grep
> Version: 3.3-1
> Severity: wishlist
> 
> (Surely someone has already asked for this, but I can't see where.
> I may have already reported this myself, and forgotten.
> If so, sorry!)
> 
> Right now if you do
> 
>     grep -eX -eY -eZ
> 
> You'll get lines that match *any of* X, Y, or Z.
> Quite often I want to search for lines that match *all of* X, Y, and Z — but 
> in any order.
> For example,
> 
>     # all 4TB 2.5-inch SATA products
>     grep -Fwi -eSATA -e2TB -e2.5in products.csv
> 
> Below is a short discussion of the workarounds I know about.
> 
> Is "grep --and" something that has already been discussed and rejected?
> I looked through debbugs.gnu.org and the source tarball, but
> I couldn't find anything about this.
> 
> 
> PS: grep -v --and would intuitively mean "not all",
> i.e. "grep -v --and -eX -eY" would return lines matching X *or* Y, but
> omit lines matching *both* X and Y.
> 
> PS: I can't decide if "--and" or "--intersection" is a better name.
> I put both in the bug subject so people searching for either will find this 
> ticket.
> I think "--all" is probably too confusing.
> 
> 
> 
> Workaround #1
> =============
> I can work around this by listing every possible order, but 1) this
> scales poorly with the number of patterns; and 2) it can't be used
> with -F.  For example,
> 
>     grep --and -eX -eY -eZ input*.txt   # becomes
> 
>     grep -eZ.*Y.*X \
>          -eZ.*X.*Y \
>          -eY.*Z.*X \
>          -eY.*X.*Z \
>          -eX.*Z.*Y \
>          -eX.*Y.*Z \
>          input*.txt
> 
> 
> Workaround #2
> =============
> I can pipe greps together.  This is what I currently do.
> This is more convenient and feels faster than workaround #1, but
> I suspect the inter-process overhead is significant.
> 
> If grep implemented this internally, it could zero-copy.
> Being able to "grep -rnH --and" &c would also be convenient.
> 
> For example,
> 
>     grep --and -F -eX -eY -eZ input*.txt   # becomes
> 
>     cat input*.txt |
>     grep -F -eX |
>     grep -F -eY |
>     grep -F -eZ

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