I have the below file ...where some of the column values should replaced with desired values ....below file u can find that 3 column where ever 'AAA' comes should replaced with ' CC '

NOTE : we have to pass the column number ,AAA,CC (modified value) as the parameters to the code.

File 1 :

E100,A456,AAA,E12
E101,A22,BBB,E13
E101,A,AAA,E14


Result file :

E100,A456,CC,E12
E101,A22,BBB,E13
E101,A,CC,E14


Please help .....

awk 'BEGIN { FS=OFS="," } $field==$from { $field=$to } 1' field=3 from=AAA to=CC inputfile

Hey, if the figures is constant you can use this

$ cat a
E100,A456,AAA,E12
E101,A22,BBB,E13
E101,A,AAA,E14

$ awk -F, '{ if($3 ~ "AAA") {print $1","$2",""CC"","$4} else {print $0} }' a
E100,A456,CC,E12
E101,A22,BBB,E13
E101,A,CC,E14

$

Hi ....
It is working fine ....thanks .....
I will get back if any required in the above .......

If iam having multiple columns to be replaced ....does the above code works ... please provide the code for the below.....
Below i have to replace 3 rd and 5 th column to 'CC' & 'XXX' repectively .....

File1 :
E100,A456,AAA,E12,MMM
E101,A22,BBB,E13,MMM
E101,A,AAA,E14 ,MMM


Result :

E100,A456,CC,E12,XXX
E101,A22,BBB,E13,XXX
E101,A,CC,E14 ,XXX

awk '
   BEGIN { FS=OFS="," }
   $3 == "AAA" { $3 = "CC" }
   $5 == "MMM" { $5 = "XXX" }
   1
    ' inputfile

nawk -v p=$1 -v old=$2 -v new=$3 'BEGIN{ OFS=FS=","}
{
for(i=1;i<=NF;i++)
{
if(p==i && $i==old)
{
$i=new
}
}
print $0
}' filename