# i used hexdump to find out the special characters
# hexdump -c file
# below commands will extract the pattern include 100 characters on right and left from the keyword pattern
tr -d '[[:space:]]' < file | grep -o '/\{0,100\}PATTERN.\{0,100\}'

join characters inside file by extracting keyword which separate by newline and special characters by including desired numbers characters on right and left

join-chars--newline-file

Bash, linux

Bash