How to look for a specific string after a matched string from a file using sed, awk or grep

Question

Sample of output stored in a file:

Provides:        Red Hat Satellite
                 Red Hat Developer Toolset (for RHEL Server)
  SKU:                 TGV123
  Contract:            59104
  Pool ID:             abcdxyz12340987

From the above output, I want to look for "Red Hat Satellite" and look for the line containing "Pool ID:" so that I get the value of the pool ID i.e. abcdxyz12340987.

How can I obtain this using sed, awk or grep? "Pool ID" may appear several lines after "Red Hat Satellite" i.e. no set number of lines in between them.

Help much appreciated!

Answer 1

sed -n '/Red Hat Satellite/,/Pool ID:/{ s/.*Pool ID:[[:blank:]]*\(.*\)/\1/p; }' file

This applies a substitution that picks out your string from after Pool ID:. It does this on any line between a line that contains the string Red Hat Satellite and the first line afterwards that contain Pool ID:. The command would print only the result of any successful substitution.

The following awk command would do the same, provided that the string at the end of the Pool ID: line does not contain any whitespace:

awk '/Red Hat Satellite/,/Pool ID:/ { if (/Pool ID:/) print $NF }' file

grep would not be the tool for this job as it is bad at handling context ("extract one line given some match on another line"). It would possibly work given some PCRE over nul-terminated lines using GNU grep, but it would be a hack.

Answer 2

With awk scripting:

$ awk '/Red Hat Satellite/{ f=1; next }f && /Pool ID:/{ print $NF; exit }' yourfile
abcdxyz12340987