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grep
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search for patterns


-c  do not print matched lines, print total count of matched lines
-d action, applies to directory files. action "read" (default), "skip", "recurse"
-e pattern, specify pattern. useful when you want to give multiple patterns 
             are specified (alternative: put those in files)
-i ignore case 
-A num, print num lines after each match
-B num, print num lines before each match
-C num, prince +/- num lines for each match (default is 2)