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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