search a string and print the string and it's header I need to search for a string (number here), and print it's header or title using grep or awk or anything. please check this example: Input file content: ##### Production_Broad: ##### 678 544 ##### IGHTY_BBBT: ##### 1666 2515 2516 2517 2518 ##### Jaguar: ##### 280 ##### Loyalty: ##### 5179 ##### MC_Addr: ##### 544 577890 ##### erce_Ban_1: ##### 7455 5656 I want to search for the number "2515", and it gives me below output: IGHTY_BBBT: 2515 and if i searched for "5179", the output should be as below: Loyalty: 5179

If headers are identified by those `#####` lines, and the list of IDs to search for is in a `ids.txt` file (one per line), you could do:


awk '
!ids_processed{ids[$0]; next}
$0 == "#####" {getline header; getline; next}
$0 in ids {print header ORS $0}' ids.txt ids_processed=1 input.txt


For instance, if `ids.txt` contains


2515
544
577890


On your sample, that would give:


Production_Broad:
544
IGHTY_BBBT:
2515
MC_Addr:
544
MC_Addr:
577890