Shell Programming and Scripting

hi Gurus,

I need find the null column in a file.
my file like below

Code:

abc, ,cde,def
abc,ded,cdd,def
abc, ,ddd,ccd
aaa,bbb,ccc,ddd

basic, I need to find the lines which second column is null

Thanks in advance

Try:

Code:

awk -F, '$2==" "' file

The code bartus11 suggested may be what you want; but you need to be careful with your terminology. By definition a null value does not contain any characters. Assuming that comma is your field separator, this file does not contain any null values. The 2nd field in the 1st and 3rd lines appears to contain a space character. If your file had been:

Code:

abc,,cde,def
abc,ded,cdd,def
abc,,ddd,ccd
aaa,bbb,ccc,ddd

then you could use the awk script:

Code:

awk -F, '$2 == ""' file

to print the lines where the 2nd field is an empty string (null value). Of course there are lots of other ways to do this too.

Thanks for you explanation. actually, in my file, it has some space.