I am able to grep multiple patterns which stored in a files. However, how could we replace the whole line with either the pattern or new string?

For example:
pattern_file: *Info in the () is not part of the pattern file. They are the intended name to replace the whole line after the pattern found. Listed here for reference.

Code:

hot.*aaa.* (H_A)
cold.*bbb.* (C_B)
cold.*aaa.* (C_A)
(.. lots more)

input_file:

Code:

hot_temp_aaa_first
hot_temp_bbb_first
cold_temp_aaa_last
cold_temp_bbb_first
hot_bake_aaa_last
hot_bake_bbb_last
cold_bake_aaa_last

Expected Output:

Code:

H_A
C_A
C_B
H_A
C_A

The output i get which not able to conclude how many pattern had been found:

Code:

hot_temp_aaa_first
cold_temp_aaa_last
cold_temp_bbb_first
hot_bake_aaa_last
cold_bake_aaa_last

How to replace them with either the new name or pattern name . The reason i want to replace them is that later i need to count how many patterns had been found. Maybe using

Code:

sort -u | wc

.
I stuck after grep all the matched, but do not know how many patterns had been found.

Code:

less input_file | grep -f pattern_file | ... | sort -u | wc

Thank you very much.

Moderator's Comments:

edit by bakunin: please use CODE-tags not only for code but also data and terminal output. Thank you.