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How to use `grep` as to choose lines with column > 1?

Answer 1

+1 A:

use the "^" char, it marks the beginning of a line

-v will not include lines starting with 1

include the extra space, so it will exclude lines like "1 asd" but not "12 asd"

grep -v "^1 "

Am 2009-09-20 13:12:29

ok, but how I can add the > 1 condition to that?

goe 2009-09-20 13:14:07

grep "^[23456789] "

Am 2009-09-20 13:15:12

strike that, bad example

Am 2009-09-20 13:15:43

What's 23456789 in this example?

goe 2009-09-20 13:16:43

it means any of this characters, so any digit char is valid

Am 2009-09-20 13:18:25

ok, but then this doesn't really support the column > 1 requirement

goe 2009-09-20 13:20:23

ur right, i updated the answer

Am 2009-09-20 13:24:48

Actually grep -v "1 " worked for me fine! THANKS

goe 2009-09-20 13:29:47

Answer 2

+6 A:

Don't use grep for this. Try awk instead:

 <pipeline> | awk '$1>1 {print $0}'

dmckee 2009-09-20 13:14:35

I can't use awk, it has to be one of the standard tools

goe 2009-09-20 13:15:22

awk is standard. it's available on every *nix

elcuco 2009-09-20 13:21:43

awk is a 'standard tool', in that it's part of the POSIX standard and should be present on any UNIX-like system which you'd expect to find grep. grep only deals with strings characters, not numbers, and so doesn't have a concept of 'greater than'.

Stephen Veiss 2009-09-20 13:23:23

I get that, but for this task I was asked not to use it.

goe 2009-09-20 13:23:43

@dmckee: beautiful solution. You can shorten the awk script to '$1>1' -- the default is to print out the line.

Hai Vu 2009-09-20 16:46:57

You know, I kind of picked up awk as I went along, and never knew ther *was* a default action. You learn something every day.

dmckee 2009-09-20 19:52:22

sounds like this is homework to teach you about regexes

IanNorton 2009-12-31 08:41:36

Answer 3

+3 A:

grep -v "^1"

-v selects non-matching lines
^ is the start of a line

EDIT: As pointed out in the comments, this solution does not filter out lines starting with multi-digit numbers. Adding a space after the 1 solves the problem:

grep -v "^1 "

Dawie Strauss 2009-09-20 13:17:56

It doesn't seem to be working as column > 1 condition

goe 2009-09-20 13:21:40

Actually grep -v "1 " worked for me fine! THANKS

goe 2009-09-20 13:28:24

This solution does not work for numbers that starts with '1': 10, 11, 100, ...

Hai Vu 2009-09-20 16:45:47

@goe, @Hai Vu: Thanks for pointing out the problem with multi-digit numbers. I edited the answer to account for it.

Dawie Strauss 2009-09-20 19:16:33

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How to use `grep` as to choose lines with column > 1?

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