Limiting awk to desired response

ZimMonkey · 06-26-2009, 02:19 PM

I'm new to programming, and was really happy when I found out how to use an outside variable in an awk command. Now I can't figure out how to limit the responses to what I want Here's what I have:

Code:

#!/bin/bash

echo "Enter Number"
read Numb

awk '$1 ~ /'$Numb'/ {print} fromfile

The fromfile has anywhere from 1 - 100 numbered lines in $1. If Numb = 1, then it prints records for 1, and 10 - 19 as well.

How do you limit it to just the number selected?

Thanks

Zim

anomie · 06-26-2009, 02:31 PM

You just need to modify your expression, a la:

Code:

$ foo=1
$ awk '$1 ~ /\<'${foo}'\>/ { print }' fromfile 
1

You might search the 'net for some regular expressions tutorials (esp. in the context of grep and awk).

ZimMonkey · 06-26-2009, 02:51 PM

Thanks for your reply. I tried it only to get

foo: command not found. Actually in my case it was Numb: command not found

I'll check my spelling.

ZimMonkey · 06-26-2009, 03:10 PM

Anomie,

Thanks for your help. I figured out what I was doing wrong. I included the () in front of, and behind foo. I took your advice and did a Google search on regular expression tutorial awk. I know what I'll be doing this weekend.

Thanks for your help

Zim

chrism01 · 06-28-2009, 08:19 PM

This is good for awk: http://www.grymoire.com/Unix/Awk.html

ghostdog74 · 06-28-2009, 09:27 PM

Quote:

Originally Posted by ZimMonkey

I'm new to programming, and was really happy when I found out how to use an outside variable in an awk command. Now I can't figure out how to limit the responses to what I want Here's what I have:

Code:

#!/bin/bash

echo "Enter Number"
read Numb

awk '$1 ~ /'$Numb'/ {print} fromfile

The fromfile has anywhere from 1 - 100 numbered lines in $1. If Numb = 1, then it prints records for 1, and 10 - 19 as well.

How do you limit it to just the number selected?

Thanks

Zim

you can do everything in awk.

Code:

awk 'BEGIN{
    printf "Enter a number: "
    getline number <"-"    
}
$1 == number{
  print
}' file

see my sig for learning awk.