How to search for lines in a file between two timestamps using Bash

log file is usually sorted by timestamp, assume the timestamp is on the first column, you could:

awk -v from="12:52:33" -v to="12:59:33" '$1>=from && $1<=to' foo.log

in this way, you can change the from and to to get different set of log entries. regex is not a good tool to do number calculation/comparison.

I believe sed is the best option:

sed -rne '/<timestamp>/,/<timestamp>/ p' <file>

ex:

tiago@dell:~$ sed -rne '/08:17:38/,/08:24:36/ p' /var/log/syslog 
May 16 08:17:38 dell AptDaemon.Worker: INFO: Processing transaction /org/debian/apt/transaction/08a244f7b8ce4fad9f6b304aca9eae7a
May 16 08:17:50 dell AptDaemon.Worker: INFO: Finished transaction /org/debian/apt/transaction/08a244f7b8ce4fad9f6b304aca9eae7a
May 16 08:18:50 dell AptDaemon.PackageKit: INFO: Initializing PackageKit transaction
May 16 08:18:50 dell AptDaemon.Worker: INFO: Simulating trans: /org/debian/apt/transaction/37c3ef54a6ba4933a561c49b3fac5f6e
May 16 08:18:50 dell AptDaemon.Worker: INFO: Processing transaction /org/debian/apt/transaction/37c3ef54a6ba4933a561c49b3fac5f6e
May 16 08:18:51 dell AptDaemon.PackageKit: INFO: Get updates()
May 16 08:18:52 dell AptDaemon.Worker: INFO: Finished transaction /org/debian/apt/transaction/37c3ef54a6ba4933a561c49b3fac5f6e
May 16 08:24:36 dell AptDaemon: INFO: Quitting due to inactivity