Use "/" command to search (forward) for a certain term and after that "n" to search the next occurence. "?" is backward search.
To do a case insensitive search use "/\c searchpattern". Case sensitivity is default.
To go to the end of file with vi use ":$" - for the beginning use ":0"
To execute multiple commands after each other in the linux shell chain them with a semicolon. In case of an error, all commands get executed. If you use &&, then the second command only gets executed if no error was reported by the first.
A nice text browser for linux is lynx!
To connect to a mail server using SSL/TLS on imap port:
openssl s_client -connect mail.myserver.com:993
If you use apt and get the following error under debian "Dynamic MMap ran out of room", and can not install any software anymore, then change the file:
/etc/apt/apt.conf or /etc/apt/apt.conf.d/70debconf
(depending on which one you have)
Add the line: APT::Cache-Limit "16777216"; to increase the cache limit for apt!
Don't forget to issue "apt-get clean" from time to time:)
mycommand > file.log 2>&1 (Writes both stdout and stderr to file.log)
mycommand &> file.log (Maybe does the same, not tested)
mycommand 2> error.log (Only write stderr to file)
Check http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-3.html for further details!