Linux Hints

All Linux Hint articles can be accessed through this page:

fail2ban startup iptables error
SSL hints and using SSL announce with rtorrent
Rtorrent compilation + problem solving
Useful debian commands
Some tips for using lftp
SMB/Samba Problem with low disc space
Compiling Truecrypt on Debian
wubi, grub, twinView and slow dns resolving
Useful tips for gcc/gdb and assembly
Rtorrent does not accept incorrect self signed server certificates
Control keys do not work in rtorrent
Debian ulimit - change maximum number of open files for a user

One tip for vi searching:
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:)

Output redirection:

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!