Running Linux, 5th Edition - Matthias Kalle Dalheimer [207]
kalle 5740 0.0 1.0 26040 11260 ? S 14:50 0:00 kdeinit: kio_file
kalle 5748 0.0 1.6 30084 16928 ? S 14:50 0:05 kdeinit: konsole
kalle 5750 1.8 4.0 57404 42244 ? S 14:50 3:48 kontact -session
kalle 5751 0.0 1.6 29968 16632 ? S 14:50 0:00 kdeinit: konsole
kalle 5754 0.0 0.5 14968 5976 ? S 14:50 0:00 /opt/kde3/bin/kde
kalle 5757 0.0 0.1 4188 1920 pts/2 Ss+ 14:50 0:00 /bin/zsh
kalle 5759 0.0 0.1 4188 1944 pts/3 Ss 14:50 0:00 /bin/zsh
kalle 5761 0.0 0.2 4684 2572 pts/4 Ss+ 14:50 0:00 /bin/zsh
kalle 5800 0.0 0.9 24484 9988 ? S 14:50 0:00 kalarmd --login
kalle 5803 0.0 2.6 36264 27472 ? S 14:50 0:05 xemacs
kalle 5826 0.0 0.1 3704 1172 pts/3 S+ 14:51 0:00 sh ./sshtunnel
kalle 5827 0.0 0.2 4956 2348 pts/3 S+ 14:51 0:02 ssh -X -L 23456:1
kalle 5829 0.1 1.9 31008 20204 ? S 14:51 0:20 kdeinit: ksirc -i
kalle 6086 0.0 0.1 3444 1244 ? S 15:07 0:00 /bin/sh /home/kal
kalle 6107 0.0 0.1 3704 1264 ? S 15:07 0:00 /bin/sh /home/kal
kalle 6115 0.7 4.2 71184 43512 ? S 15:07 1:29 /home/kalle/firef
kalle 6118 0.0 0.3 6460 3612 ? S 15:07 0:00 /opt/gnome/lib/GC
kalle 6137 0.0 0.5 8232 5616 ? S 15:08 0:03 perl /opt/kde3/bi
kalle 6186 0.0 2.9 42300 30384 ? S 15:10 0:03 kdeinit: konquero
kalle 6497 0.1 1.6 30592 17424 ? R 15:20 0:11 kdeinit: konsole
kalle 6498 0.0 0.2 4724 2624 pts/1 Ss+ 15:20 0:00 /bin/zsh
kalle 6511 0.9 3.0 39932 31456 pts/1 S 15:20 1:37 xemacs
kalle 6720 0.0 0.2 4584 2500 pts/5 Ss 15:32 0:00 /bin/zsh
root 6740 0.0 0.1 3480 1264 pts/5 S 15:32 0:00 su
root 6741 0.0 0.1 3608 1732 pts/5 S 15:32 0:00 bash
kalle 6818 0.0 1.6 30152 17316 ? S 15:39 0:00 kdeinit: konsole
kalle 6819 0.0 0.2 4492 2396 pts/6 Ss+ 15:39 0:00 /bin/zsh
kalle 6948 0.0 1.6 29872 16564 ? S 15:48 0:00 kdeinit: konsole
kalle 6949 0.0 0.1 4188 2040 pts/7 Ss 15:48 0:00 /bin/zsh
kalle 6982 0.0 0.1 4556 1908 pts/7 S+ 15:50 0:00 ssh cvs.kdab.net
at 8106 0.0 0.0 1432 536 ? Ss 17:24 0:00 /usr/sbin/atd
postfix 8672 0.0 0.1 4220 1448 ? S 18:09 0:00 pickup -l -t fifo
postfix 8779 0.0 0.1 4208 1396 ? S 18:15 0:00 proxymap -t unix
postfix 8796 0.0 0.1 4744 1784 ? S 18:17 0:00 trivial-rewrite -
postfix 8797 0.0 0.1 4904 1848 ? S 18:17 0:00 cleanup -z -t uni
postfix 8798 0.0 0.1 4376 1768 ? S 18:17 0:00 local -t unix
root 8807 0.0 0.0 1584 700 ? S 18:19 0:00 /USR/SBIN/CRON
kalle 8808 0.0 0.1 3112 1144 ? Ss 18:19 0:00 fetchmail
root 8822 0.0 0.0 2164 688 pts/5 R+ 18:20 0:00 ps aux
Programs That Serve You
We include this section because you should start to be interested in what's running on your system behind your back.
Many modern computer activities are too complex for the system simply to look at a file or some other static resource. Sometimes these activities need to interact with another running process.
For instance, take FTP, which you may have used to download some Linux-related documents or software. When you FTP to another system, another program has to be running on that system to accept your connection and interpret your commands. So there's a program running on that system called ftpd. The d in the name stands for daemon, which is a quaint Unix term for a server that runs in the background all the time. Most daemons handle network activities.
You've probably heard of the buzzword client/server enough to make you sick, but here it is in action—it has been in action for decades on Unix.
Daemons start up when the system is booted. To see how they get started, look in the /etc/inittab and /etc/xinetd.conf files, as well as distribution-specific configuration files. We won't go into their formats here. But each line in these files lists a program that runs when the system starts. You can find the distribution-specific files either by checking the documentation that came with your system or by looking for pathnames that occur frequently in /etc/inittab. Those normally indicate the directory tree where your distribution stores its system startup files.
To give an example of how your system uses /etc/inittab, look at one or more lines with the string getty or agetty. This is the program that listens at a terminal (tty)