Grep for NULL in a pipe delimited file

sureshg_sampat · #1 (**permalink**) 11-20-2006

hi,

How can I check for a field in a pipe-delimited file having a NULL value in Unix using a grep command or any other command.

Please reply

aigles · #2 (**permalink**) 11-20-2006

What do you mean by NULL field ?
An empty field or a field equal to binary zero ?

Jean-Pierre.

Yogesh Sawant · #3 (**permalink**) 11-21-2006

Quote:

Originally Posted by sureshg_sampat

hi,

How can I check for a field in a pipe-delimited file having a NULL value in Unix using a grep command or any other command.

Please reply

maybe this is what you want:

Code:

perl -n  -e 'print $_ if m#\|\|#' somefile

cskumar · #4 (**permalink**) 11-21-2006

awk -F "|" '{for (i=0;i<=NF;i++){if(length($i) ==0) { val=$0 }} print val}' file1 > outputfile

Yogesh Sawant · #5 (**permalink**) 11-21-2006

or this might be as simple as:

Code:

grep "||" somefile

aigles · #6 (**permalink**) 11-21-2006

A grep for || doesn't select null field at start or end of line.
Try :

Code:

egrep '^\||\|\||\|$' somefile

Note: The egrep command is the same as the grep -E command.

Jean-Pierre.

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