Output matched string through end of tab-indented section? - linux

Question

Sample code from pci.ids below. I want to use the class code from lspci (lets say it's 0580) and have it navigate to C 05 > 80: Memory controller. I feel the most appropriate way (to avoid returning a value from the wrong class) is to just cut the section of C 05 first, then look for 80. Grep -A... will return everything after, and therefore if the 80 doesn't match something in C05 it would jump down to some Cn which contains an 80 element.
C 03 Display controller
00 VGA compatible controller
00 VGA controller
01 8514 controller
01 XGA compatible controller
02 3D controller
80 Display controller
C 04 Multimedia controller
00 Multimedia video controller
01 Multimedia audio controller
02 Computer telephony device
03 Audio device
80 Multimedia controller
C 05 Memory controller
00 RAM memory
01 FLASH memory
80 Memory controller
C 06 Bridge
00 Host bridge
01 ISA bridge
02 EISA bridge
03 MicroChannel bridge
04 PCI bridge
00 Normal decode
01 Subtractive decode
05 PCMCIA bridge

Answer 1

To pass "0580" into the awk program:
awk -v value='0580' '
BEGIN {a = substr(value,1,2); b = substr(value,3,2)}
$1 == "C" { p = ($2 == a)}
p && $1 == b {print; exit}
' file
If the first word is "C", set a boolean to true if the second word is "05".
If the flag is true and the first word is "80", print the current line and exit.