Shell Programming and Scripting

KEY|COLUMN_NAME|SOURCE_VALUE|TARGET_VALUE
1  | CITY      | JUKIL      |JKHJKDH
1  | NUMBER    | 3          |9
1  | JULU      |i8          |i10
2  | CITY      | HDJ        |HIK
2  | JULU      |i20         |i30
3  | CITY      | JUIL       |JKHDH
3  | NUMBER    | 10         |11

KEY=1| CITY=JUKIL,JKHJKDH |NUMBER=3,9 | JULU=18,i10
KEY=2| CITY=HDJ,HIK       |JULU=i20,i30
KEY=3| CITY=JUIL,JKHDH    |NUMBER=10,11

awk -F "|" 'NR>1{if(a[$1]){a[$1]=a[$1]"|"$2"="$3","$4}else{a[$1]="KEY="$1"|"$2"="$3","$4}}END{
for(i in a) { print a[i]}}' file

awk -F "|" 'NR>1                         # we check for lines where except first line

{if(a[$1]){                             # Here check if a[$1] is already present or not.

a[$1]=a[$1]"|"$2"="$3","$4}             # If a[$1] presents then append the $2,$3 and $4 to a[$1]

else{a[$1]="KEY="$1"|"$2"="$3","$4}}     # If a[$1] is not present then a[$1] is initilised as required. Just assume $1 = 1,1,1,2,2,3,3 in this case.

END{for(i in a) { print a[i]}}' file     # Here after all the assigning part is done. Get all the index from the a and print a[i]. 

for(i in a)    # Give you all the indexes present in array like here i is 1,2,3