In my final preperation for the RHCSA I've gone through and found some good references for a "cheat sheet," pulling from Michael Jang's RHCSA/RHCE study guide as well as this fantastic wiki: http://rhce.co/rhel6/Main_Page for those seeking their RHCSA.The RHCE portion is incomplete, but the RHCSA part is complete and only slightly outdated. It is a fantastic resource.
Between those two sources, notes from Tommasino's Hands-on Guide to the RHCSA/RHCE, and my personal knowledge, I put together this study guide based on the RE200 exam objectives as of 2012 05 15.
Objectives:
Understand and use essential tools
- Access a shell prompt and issue commands with correct syntax.
- Change TTY
- ctrl+alt+F1
- F1-F7 are available
- Icon on top of left of GUI
- -Menu/Applications/System Tools/Terminal
- Use input-output redirection (>, >>, |, 2>, etc.).
- > overwright
- < send into a command or file
- >> append
- << append into a command or file
- cat >> hoge.txt << _end
- cat the file
- enter text in tot he file until _end has been met
- | funnel into
- 2> redirect errors
- 2>&1 redirect errors to std out
- Use grep and regular expressions to analyze text.
- grep for nocase
- # grep -i
- egrep ‘^(wheel|root)’ /etc/group
- less file | [e]grep string
- inverted search with grep and egrep
- grep -v ^# /etc/nsswitch.confegrep -v ^# /etc/nsswitch.conf
- Access remote systems using ssh and VNC.
- SSH user_name@host
- ssh with x windows pass through
- SSH host -lX user_name
- vncviewer remote_host
- Log in and switch users in multiuser runlevels.
- Runlevels 2, 3, 5
- su - username
- Archive, compress, unpack, and uncompress files using tar, star, gzip, and bzip2.
- # gzip big.jpg# bzip2 big.jpg# gzip -d big.jpg.gz# bzip2 -d big.jpg.bz2# tar czvf home.tar.gz /home# tar xzvf home.tar.gz /home# yum install star# star -xattr -H=exustar -c -f=home.star /home/# star -x -f=home.star
- Create and edit text files.
- touch filename
- vi filename
- Create, delete, copy, and move files and directories.
- touch, rm, rmdir, rm -fr, cp, mv -r, mv
- Create hard and soft links.
- ln source destination ## hard link
- ln -s source dest,
- List, set, and change standard ugo/rwx permissions.
- ls -l
- chmod +x +w +r,
- chmod 755 ##folders default
- chown user.group
- chgrp
- Locate, read, and use system documentation including man, info, and files in /usr/share/doc.
- man command_name
- man -k command_name
- search for command in the doc directory
- ls -l /usr/share/doc | grep httpd
Note: Red Hat may use applications during the exam that are not included in Red Hat Enterprise Linux for the purpose of evaluating candidate's abilities to meet this objective.
