Replace whole line when match found with sed

Question

I need to replace the whole line with sed if it matches a pattern. For example if the line is \'one two six three four\' and if \'six\' is there, then the whole

Answer 1

To replace whole line containing a specified string with the content of that line

Text file:

Row: 0 last_time_contacted=0, display_name=Mozart, _id=100, phonebook_bucket_alt=2
Row: 1 last_time_contacted=0, display_name=Bach, _id=101, phonebook_bucket_alt=2

Single string:

$ sed 's/.* display_name=\([[:alpha:]]\+\).*/\1/'
output:
100
101

Multiple strings delimited by white-space:

$ sed 's/.* display_name=\([[:alpha:]]\+\).* _id=\([[:digit:]]\+\).*/\1 \2/'
output:
Mozart 100
Bach 101

Adjust regex to meet your needs

[:alpha] and [:digit:] are Character Classes and Bracket Expressions