For the Love of Pipes

Re:For the Love of Pipes by kps on Tuesday January 22, 2019 @04:10PM (#18972506)

In this particular example, ‘unnecessary use of cat’ is accompanied by ‘unnecessary use of grep’.

    cat input | grep '^x' | sed 's/foo/bar/g'

→

    sed '/^x/s/foo/bar/g' <input

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Re:For the Love of Pipes by irishsultan on Wednesday January 23, 2019 @09:06AM (#18978168)

That's not the same thing. The sed output will still keep lines not starting with x (just not replacing foo with bar in those) where grep will filter those out.

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Re:For the Love of Pipes by kps on Wednesday January 23, 2019 @11:03AM (#18979358)

Yeah, Muphry's law at work. Corrected version:

   sed -n '/^x/s/foo/bar/gp' <input

This may be an inadvertent argument for the ‘connect simpler tools’ philosophy.

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