Having an input for a variable, dynamically create values for another variable using a static list

Question

Having an input for a variable, dynamically create values for another variable using a static list

I have a set of hostnames, I would want to assign these hostnames to the variable SERVERS or CLIENTS. When the hostname from the given list is selected for SERVERS it should get removed from the CLIENTS variable.

Note:- variable SERVER might have more than one hostname

LIST_OF_NODEScn01,cn02,cn03,cn04,cn05,cn06,cn07,cn08,cn09,cn10

INPUT=cn01

OUTPUT:-

SERVERS=cn01
CLIENTS=cn02,cn03,cn04,cn05,cn06,cn07,cn08,cn09,cn10
(echo "server $SERVERS"; echo "client $CLIENTS") > cn01.cmd

INPUT=cn02

OUTPUT:-

SERVERS=cn02
CLIENTS=cn01,cn03,cn04,cn05,cn06,cn07,cn08,cn09,cn10
(echo "server $SERVERS"; echo "client $CLIENTS") > cn02.cmd

SERVERS=cn01,cn02
CLIENTS=cn03,cn04,cn05,cn06,cn07,cn08,cn09,cn10
(echo "server $SERVERS"; echo "client $CLIENTS") > cn01_cn02.cmd

INPUT:- Values for the SERVERS for example

If cn03, cn07 is provided as input then

SERVERS=cn03,cn07
CLIENTS=cn01,cn02,cn04,cn05,cn06,cn08,cn09,cn10
(echo "server $SERVERS"; echo "client $CLIENTS") > cn03_cn07.cmd

I tried the following

for i in cn{01..10}; do 
   echo $i
   sed "s/$i//g" nodes.txt | sed 's/,,/,/g'| sed 's/,*$//g' | sed 's/^,//g' 
done

Answer 1

If I understood your requirement correctly, could you please try following.

cat script.ksh
echo "Enter cn values in form of cn01 or cn02 etc here...."
read value

SERVERS="$value"
LIST_OF_NODES="cn01,cn02,cn03,cn04,cn05,cn06,cn07,cn08,cn09,cn10"   

awk -v servers="$SERVERS" -v clients="$LIST_OF_NODES" '
BEGIN{
  s1=","
  split(servers,array,",")
  for(i in array){
    gsub(s1 array[i] s1,s1,clients)
    gsub("^"array[i] s1,"",clients)
    gsub(s1 array[i]"$","",clients)
  }
  gsub(/,/,"_",servers)
  print clients > servers".cmd"
}'

Created above script. Now following is when we run the script:

./file.ksh
Enter cn values in form of cn01 or cn02 etc here....
cn04,cn07

Output file named cn04_cn07.cmd will be created.