Maybe someone would still like an answer to this old question. You can use regular expression (Regex) pattern matching.
For instance you can run the following command to include/exclude/count/begin/section any messages with a keyword in them:
INCLUDE:
show log | include CRYPTO
show log | i OSPF
show int status | i notconnect
INCLUDE MULTIPLE:
Combine multiple options using a pipe "|" symbol to separate them:
show log | i CRYPTO|OSPF|BGP|LOGIN|LOGOUT
EXCLUDE:
show log | exclude ADJCHG
show ip int br | ex una
show int status | e notconnect
START OF LINE:
to show a route that begins with a pattern, begin with the caret symbol (^) which means "beginning of line":
show ip route | i ^O
show ip route | i ^O|^S
show ip route | i ^O|^B|^S
COUNT:
or count a matching criteria - this will count the number of static routes in your route table:
show ip route | count ^S
SECTION:
to see all the indented lines following a matched criteria such as bgp, route-maps, or line commands
show run | section route-map
show run | sec bgp
show run | sec line
BEGIN:
the begin operator works well if the section of configuration is not indented, or you're just looking to start at a general area within your config, or syslog output
show run | begin interface
show run | b banner
show log | b May 16
Regular expression (REGEX) is also useful for matching criteria in route-maps. There are good articles on the internet explaining Regex special characters. Here are a few of the basics.
. = any character
* = any number of times
.* = any character any number of times (basically means anything)
| = or
[0-9] = any single digit matching the numbers 0 through 9.
for instance show log | i Vlan[9][0-9][0-9] matches Vlan900 through 999 in your syslog messages
[a-z,A-Z] = any letter upper or lower case
^ = beginning of line
$ = end of line
^$ = an empty line a.k.a. carriage return (a line that starts and ends without any other characters on that line)
_ = a space
\ = escape (removes special meaning from special characters, or applies special meaning to standard characters)
for instance \$ means match the dollar sign instead of the end-of-line
https://www.cisco.com/c/en/us/td/docs/ios/12_2/dial/configuration/guide/dafaapre.html Cisco Doc on Regex
https://www.rexegg.com/regex-quickstart.html Regex Cheat Sheet
https://packetlife.net/blog/2008/may/10/extracting-bgp-info-regex/ Packet Life BGP Regex Cheat Sheet
https://regexlib.com Regex Library and Test pattern matching tools
