UNIX for Advanced & Expert Users

Code:

grep -E '^([^|]+[|]+){5}5000' <file_name>

this command searches value 5000 in only 6th column from provided file where pipe ( | )is delimiter which separate columns... can some one plz explain me what

Code:

'^([^|]+[|]+){5}5000'

actually does..?

Match a string starting at the beginning of the string (^) consisting of 5 sequences ((...){5}) of one or more (+) non pipe symbols ([^|]) followed by one or more pipe symbols ([|]+) followed by 5000. If there are empty fields (i.e., adjacent | characters), this extended regular expression may find a 5000 in a field after the 6th column. If empty fields are allowed in your input, I would use:

Code:

grep -E '^([^|]*[|]){5}5000' <file_name>

instead.
The * instead of the + says search for zero or more instead of one or more. Getting rid of the + after the [|] says to match exactly one instead of one or more.