Each Linux system administrator needs to have a basic understanding of Regular Expressions, and how to use them. This learning activity will provide you with the chance to practice using some of the more common regular expressions, and utilizing output redirection to create new files.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Use regular expressions to locate information on http services.
Create a file called http-services.txt in the cloud_user’s home directory that contains the values from /etc/services containing ‘http’ at the beginning of each line, but not containing an ‘x’ at the end.
This can be accomplished via the following command:
grep ^http[^x] /etc/services > http-services.txt- Use regular expressions to find port information for LDAP services.
Look for everything that begins with ‘ldap’ within
/etc/serviceswhere the fifth character can be any alphanumeric character and the sixth character is not the letter ‘a’. The results from this search should be placed in a new file in thecloud_user‘s home directory calledlpic1-ldap.txt.This can be accomplished with the following command:
grep ^ldap.[^a] /etc/services > lpic1-ldap.txt- Create a new file based off of http-services.txt.
Finally, remove any value from http-services.txt containing the word ‘service’ at the END of the string and concatenate those values to a new file in the cloud_user’s home directory called http-updated.txt
This can be accomplished with the following command:
grep -v service$ http-services.txt > http-updated.txt
