grep&find

grep pattern file

grep -i pattern file

    ignore the uppercase/lowercase distinctions during comparisons.

grep -f pattern file

        only the name of the file with mathing lines are listed (once)

grep -n pattern file

     Each line is preceded by its relative line number in the file starting at 1.

     This option is ignored if -c, -b, -l, or -q is specified.

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find . -name 'abc'

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