Shell Programming and Scripting

Hi,

In a file, I have several time

Code:

    <IP>232.0.1.164</IP>
...        
    <IP>232.0.1.135</IP>

I need to replace all the random IP addresses , by 239.0.0.1 and 239.0.0.2 , alternatively.

I try this

Code:

grep "<IP>" tsp.xml | awk '{if(NR % 2)print $0}' | cut -d"<"  -f2 | cut -d">" -f2

It gives all the IP Address of the Odd occurences, but I don't know how to substitute it in the file.

I see also the gsub function of awk but I lost.

Can you help me ?

Best Regards,
Frédéric

try:

Code:

awk 'BEGIN {a[1]="239.0.0.1"; a[0]="239.0.0.2"} /<IP>/ {sub(">.*<",">" a[NR %2] "<")} 1 ' tsp.xml

Thanks you rdrtx1,

With your command the half first part of the IP is replaced by 239.0.0.2 and the second part is 239.0.0.1

Is it possible to have a switching, for the Odd occurrences the IP 239.0.0.1 and for the Even occurrences the IP 238.0.0.2 ?

Regards,

---------- Post updated at 08:26 AM ---------- Previous update was at 08:15 AM ----------

It seems NR , do the modification in function of the line number and not the occurrence number.

It seems, In the first part the "grep <IP>" is on Odd line number and in the second part on Even

---------- Post updated at 08:39 AM ---------- Previous update was at 08:26 AM ----------

This Command works

Code:

awk 'BEGIN {a[1]="239.0.0.1"; a[0]="239.0.0.2" ; n=0} /<IP>/ {sub(">.*<",">" a[n%2] "<"); n++}; 1 ' tsp.xml

Thanks for your support

You may want to try this one:

Code:

$ awk '/<IP>/ {sub(">.*<",">239.0.0"n++%2+1"<")}1' tsp.xml