I was having a file with format as below.
1. Different fields with a field seperator.
2. Multiple lines.
3. There were multiple lines with same strings to be replaced but there are few lines to match a pattern string to execute find and replace.
Used the following vi editor command.
%g for using regular expression command in vi.
^.*pattern*.$ for searching and selecting lines containing the (semi-)word pattern.
s/find/replace/g for string find words with value “find” and replace them with string “replace”.