Shell Programming and Scripting

Hello,

I have some problem in inserting the space for the pairs of columns.

I have the input file :
I used this code below in replacing it using space in specific column (replace space in each two columns)

Code:

sed -e "s/,/ /2" -e "s/,/ /3" inputfile

Output showed :
However, I have many columns around 17,000 columns. I do not know how to use loop in this command. Could you please suggest me?

Thanks in advance

sed have no loop command, use awk

Code:

awk -F, '{for (i=1;i<=NF;i+=2) printf "%s,%s ",$i,$(i+1);print ""}' inputfile
A,A B,C D,R
C,R A,A B,R
R,D A,R B,R

Great. It is worked. Thank you very much Jotne.

You are mistaken. Explicit looping can be implemented with labels ( : ) and either or both of the branching (b) and testing (t) commands. However, a sed solution does not require any explicit looping, only a single substitution command:

Code:

sed 's/\([^,]*,[^,]*\),/\1 /g'

N.B. The sed solution never alters the number of fields in a record. That AWK solution will add a comma and an empty field if there are an odd number of fields (i.e. an even number of commas).

Regards,
Alister