Parse Log Files with sed
When parsing log files sed is not the go-to tool for most techs, but it offers a pretty neat feature: the ability to easily search a log file for a specific date/time range.
sed -n '/Dec 30 13:00/p' /var/log/messages
Date Range Matching
sed -n '/Dec 30 13:00/,/Dec 30 14:00/p' /var/log/messages
If your search term contains the character
/, you can change the delimiter used by sed:
sed -n '\|30/Dec/2015:21|,\|30/Dec/2015:23|p' /var/log/httpd/access.log
Command Break Down
This flag tells sed to suppress all output except for matching lines.
/Dec 30 13:00/
Match lines containing the string “Dec 30 13:00”. The search term can be a regular expression, /regexp/.
/Dec 30 13:00/,/Dec 30 14:00/
Match all content from the first “Dec 30 13:00” to the first “Dec 30 14:00”.
Print the current pattern space.
Change the delimiter to
| can be any character.