Hello,

I have a table as shown below. I want to concatenate values in col2 and col3 based on a value in col4.

1	X	Y	A
3	Y	Z	B
4	A	W	B
5	T	W	A

1	X	Y	YY
3	Y	Z	YZ
4	A	W	AW
5	T	W	WW

awk '$4!="A"{$4=$2$3;}$4=="A"{$4=$3$3;}1' OFS="\t" infile

Try:

$ awk '$4=$4=="A"?$3$3:$2$3' OFS="\t" file

The script by bipinajith is not giving any output while script by RudiC is working fine.

Manoj

I'm not sure which OS and awk you are running! Here is the o/p from 3 different plaforms:-

HP-UX

awk '$4!="A"{$4=$2$3;}$4=="A"{$4=$3$3;}1' OFS="\t" infile
1       X       Y       YY
3       Y       Z       YZ
4       A       W       AW
5       T       W       WW

gawk '$4!="A"{$4=$2$3;}$4=="A"{$4=$3$3;}1' OFS="\t" infile
1       X       Y       YY
3       Y       Z       YZ
4       A       W       AW
5       T       W       WW

nawk '$4!="A"{$4=$2$3;}$4=="A"{$4=$3$3;}1' OFS="\t" infile
1       X       Y       YY
3       Y       Z       YZ
4       A       W       AW
5       T       W       WW

Hi bipinajith,
your code is working fine, could you please also explain it a bit :

awk '$4!="A"{$4=$2$3;}$4=="A"{$4=$3$3;}1' OFS="\t" infile

Everything in awk has the form condition{action} . If the condition evaluates to 1 then the action is performed. If the condition is omitted then the default condition is 1, so the action is always performed. If the action is omitted then the default action is performed, which is {print $0} .

In this case the condition is "1" so that evaluates to 1 and the action is omitted, therefore {print $0} is performed, which is "print the entire record".