| LevSelector.com |
Unix
| On this page: | Other pages: | ||
| • intro,
manpages, tutorials
• books • prompt & terminal • unix editos • more • unix flavors Linux, Solaris, BSD, SCO, AIX, HP, Digital, IRIX • commands examples |
• shell
scripting
• tcsh • Bourne sh_short • Bourne sh_tutorial • vi_mode_commands.html • emacs_mode_commands • command_line_editing_tips • vi-ref - vi-ref.pdf |
• less
•
• awk • sed • grep • Tcl/Tk • Learning the UNIX Operating System • unix hints and hacks • my page for linux • more commands (random flow) • network_admin• less • • make • building |
| intro, tutorials | home - top of the page - |
Unix - runs behind ~70% of the Internet, very stable, originally written in C. It is (was) simple, small and open. This allowed it to mutated like a virus and to spread onto various platforms. Why Unix is better or how to hate Unix - read more on Operating Systems page.
Some links:
- www.iki.fi/era/unix/
- History, Useless Use Of ... Awards, etc
- www.iki.fi/era/unix/shell.html
- Steve Bourne's original tutorial.
- www.ocean.odu/edu/ug/shell_help.html
- quickly written by the looks of it, but seems to have the important stuff.
- www.mpi-sb.mpg.de/~uwe/lehre/unixffb/quoting-guide.html
- a pretty definitive document on quoting and escape characters.
Examples of tutorials:
• www.google.com/search?q=unix+tutor+commands
• www.emba.uvm.edu/CF/basic.html
- - basic unix commands with short descriptions
man pages:
| The easiest way to find many man pages for a command is by searching
google for: manpage command
• www.engin.umich.edu/htbin/mangate?manpage=perl - perl • www.engin.umich.edu/htbin/mangate?manpage=ls - ls • www.engin.umich.edu/htbin/mangate?manpage=troff
- troff
from the prompt:
Reformatting documentaion on unix prompt
|
Good starting tutorials:
| • www.ora.de/catalog/unixcd/chapter
- Unix Commands (from O'Reilly "Unix in a Nutshell, Chapter 2)
• www.webreference.com/programming/unix/ - tutorials • www.infojack.com/ - tutorials, books and tests • www.itspace.com/ - unix resources • www.oase-shareware.org/shell/ - all about Unix shells • kulichki.rambler.ru/moshkow/ - many books in Russian |
| unix books | home - top of the page - |
| • Unix : Visual Quickstart Guide (Visual
Quickstart Guide Series) by Deborah S. Ray, Eric J. Ray
• UNIX For Dummies - by John R. Levine, Margaret Levine Young • Learning the UNIX Operating System - (Nutshell Handbook, O'Reilly) - short • Programming With Gnu Software (Nutshell Handbook) • Unix in a Nutshell: A Desktop Quick Reference for SVR4 and Solaris 7 (3rd Edition) - by Arnold Robbins, Daniel Gilly • UNIX Power Tools Programming With Gnu Software (Nutshell Handbook) • UNIX System Administration Handbook - by Evi Nemeth, et al (Paperback - August 2000) • Essential System Administration : Help for Unix System Administrators (Nutshell Handbook) • The UNIX Programming Environment - by Brian W. Kernighan, Rob Pike (Contributor), Robert Pike • Advanced Programming in the Unix Environment
(Addison-Wesley Professional Computing Series) W. Richard Stevens
• Interprocess Communications in Unix :
The Nooks and Crannies - by John Shapley Gray
|
See more books listed on pages devoted to shells, misc. tools, sys.
administration, network, email, and Linux.
| editing on the prompt | home - top of the page - |
When you start working on the prompt - you want to select the shell
to use (usually ksh or bash) and editing mode
(vi or emacs).
Ask your sysadmin to set it up for you (edit /etc/passwd
file and .profile ,
.bash_profile , .bashrc in your
home directory).
If your terminal is in some strange state - try doing "stty sane".
| Here are some commands in .profile file for Korn shell:
EDITOR=vi VISUAL=vi # this overrides EDITOR set -o vi # this is the same again PS1='$LOGNAME'@`uname -n`:'$PWD $ ' Command line editing is usually done in one of 2 modes: vi or emacs.
vi-mode is not intuitive for many people. Arrows don't work as
you would expect them to work. You have to constantly switch between command
and insert modes. Here are some sites to help you love vi: If you are not a vi lover - then you probably will be
much happier with emacs mode:
For modern linux-es default is bash in emacs
mode.
|
Using xterm - examples:
| dtterm -d 10.3.3.101:0.0 -fg black -bg white
&
xterm -d daddypc:0.0 -fg green -bg black & xemacs -d daddypc:0.0 & alias term='xterm -d daddypc:0.0 -fn -*-Fixed-Medium-R-*-*-*-120-75-75-*-*-ISO8859-1 -bg DarkCyan -fg White -geom 90x30 -cr red &' alias term0='xterm -d daddypc:0.0 -fg black -bg white &' alias term1='xterm -d daddypc:0.0 -fn -*-Fixed-Medium-R-*-*-*-120-75-75-*-*-ISO8859-1 -bg black -fg LemonChiffon -geom 90x30 -cr red' alias term2='xterm -d daddypc:0.0 -fn -*-Fixed-Medium-R-*-*-*-140-75-75-*-*-ISO8859-1 -bg black -fg LemonChiffon -geom 100x40 -cr red' |
You can get syntax color coding in vim via CRT-telnet (www.vandyke.com):
| - set CRT-telnet session to ansi emulation (you can change ANSI
colors in Global settings).
- set $TERM to ansi on unix - in vim settings file .vimrc add command :syntax on |
• www.cs.utk.edu/~shuford/terminal/unix_terminal_news.txt
- discussion about using terminals
• www.unm.edu/cirt/introductions/unix/unix10.html
- using X-windows
• www.chemie.fu-berlin.de/chemnet/general/aboutx.html
- FAQ about X-windows
• www2.ncsu.edu/cc/pub/tutorials/unity_intro/31_colors.html
- setting colors in X-windows
vi - exists on all unix boxes. So knowing it is a must for any unix programmer. vi chokes on log files with very long lines - so you better use vim.
vim (vi improved) - http://www.vim.org - great editor. Can read very long files with very long lines without problems (standard vi is known for choking on long lines). Vim exists on many platforms, including unix and windows. It has support for ctags (wa to jump to function definition and back). On linux when you type "vi" - you are actually getting vim.
emacs - another great highly-customizable editor. Editor of choice of many C++ old-timers.
pico - simple text editor (was part of Pine email client).
nano - improved version of pico - http://www.nano-editor.org
joe - http://joe-editor.sourceforge.net/ - great editor (this page also lists many other editors).
POSIX - (Portable Operating System Interface) is a set of standard operating system interfaces. It was based on the UNIX operating system partly because it was "manufacturer-neutral." Read on www.whatis.com
More on Unix:
• USENET
FAQs
• Unix
Programming FAQ
• Unix
Links
• The
Unofficial Guide to Solaris
• OO
Network Prgming with Unix
• Unix
systems programming
• sockets
• Vi
FAQ
• Advanced
Unix IPC
• unix
sockets programming in c
See also:
• www.gnu.org
- GNU software and compiler
• www.cerfnet.com/~mpcline/c++-faq-lite/
- C++ FAQ
• www.eskimo.com/~scs/C-faq/top.html
- C FAQ
Linux
• see
my page for
linux
• www.linux.org
- Linux
• www.linux.org/dist/english.html
- misc distributions (Red Hat, Caldedra, Debian GNU/Linux, Slackware, S.u.S.E.
and many-many others).
• www.linux.org/vendors/retailers.html
- retailers in different countires (long list)
• www.redhat.com
- Linux
• www.suse.com
- Linux
Sun Solaris
• www.sun.com
- Solaris operating system (available for Intel-PC for $15).
( also
www.sunfreeware.com
- everything you need for operating system )
•
info.rutgers.edu/Techdir/solarisbody.html
- Solaris system configuration
•
www.fwi.uva.nl/pub/solaris/solaris2.html
- Solaris FAQ
•
http://docsun.cso.uiuc.edu/cgi-bin/nph-dweb/ab2
- Solaris Online Documentation Library - excellent resource
•
http://soldc.sun.com/
- Solaris Developer's Connection
BSD (Berkeley Systems Distribution)
• www.bsd.org
- lists several different BSDs (FreeBSD,
NetBSD,
OpenBSD,
BSDI
Internet Server (BSD/OS) )
for example, FreeBSD
is used by famous sites like Yahoo and HotMail ( http://freebsd.peon.net/
- tutorials )
• www.bsdi.com
- commercial expensive BSD
SCO (The Santa Cruz Operation, Inc.)
• www.sco.com
- good stable unix on Intel platform:
•
www.sco.com/unix/market.html
1987: AT&T + Sun
= System V, revision 4 (SVR4)
1993: AT&T sells its
unix to Novell
1995: sold to SCO.
AIX (An IBM unix)
• www.ibm.com/servers/aix/
- unix from IBM
HP-UX (Hewlett Packard unix)
• www.hp.com
- unix from Hewlett Packard - good choice (amazon.com uses HP servers)
DIGITAL UNIX
• www.compaq.com/enterprise/
( read also • www.operatingsystems.net/oses/decunix.htm
)
( ULTRIX -
a BSD based + some features from System V and DEC. It was made by
DEC, then replaced by Digital Unix ).
IRIX
• www.sgi.com/
- Silicon Graphics, Inc.
• www.microware.com/Products/Software/OS9.html - OS-9 - small, but very nice and robast UNIX-like RTOS
and many-many more types of Unix
| commands examples | home - top of the page - |
You can combine several commands on one line using pipes and redirecting
input/output. Here are some examples:
sort < data > junk
tr a-z A-Z < in > out
ls -s | tail +2 | sort -rn | head -5
ps -ef | grep http
tar cvf - . | gzip -9 > mmm.tar.gz
gunzip < mmm.tar.gz | tar -xvf -
ps -ef | grep daemon | cut -c10-14
ls -l | grep "^d" | cut -c55-80
cat tt | sort | uniq -d
| ps -ef |
grep appl /usr/ucb/ps aux | head find . -type f -print | xargs fgrep -l 'pattern goes here' /dev/null/ find . -mtime -1 -print find . -name '*.pl' -exec perl -wc {} \; uname -a tail -f somelog - to see the tail of the
log as it changes |
| nslookup `hostname` netstat ifconfig /etc/hosts /etc/resolv.conf /var/spool/cron/crontabs/ ... |
tar everything in current
directory: |
|
to uncompress .bz2 files use: bunzip2 somefile.bz2 |
|
Recursive
operations - use -r ( or -R) option: |
| one-liners for Unix:
rename many files simultaneously (here it renames *.tar into *.tar7): ls -1 *.tar | perl -nle '$old=$_;s/(\.+)tar/$1tar7/;rename($old, $_);' - print help for all commands of perforce (p4) source control system: p4 help commands | perl -nle 'm/^\s+(\w+)\s/; print "$1\n";' - | xargs p4 help |
| if you received an tar.gz file uuencoded in the body of the message
between the begin..end lines (begin line contains real file name, for example
SelfGOL.tar.gz): save it as text file "file.txt" uudecode -p < file.txt | gunzip | tar -xzvf - or (step-by-step): |
| Get gcc (GNU C-compiler) binary - version 2.8.0 or better.
/appl/archives/gcc.tar.Z copy it into /appl/Archives directory, uncompress it and untar it (tar xvf ...) This will put all necessary binary files in their places. Test that the compiler is alive: gcc -v - should show the version When installing the software we will be running scripts which will
be looking for a C-compiler. Some scripts want to see ln -s 'whence gcc' /usr/local/bin/cc This may be OK if there are no other C-compilers used on this machine.
make CC=gcc Or you can define environment variables before running make or configure script: CC=gcc;export CC (sh) Now you can test: env For some scripts it works better if you CC=gcc; export CC; ../dist/configure
(sh) |
To sync directory from old computer to a new computer:
|
sudo - utility to run a command with privileges of another user (typically as root).
( example: sudo hdparm
-t /dev/hdb5 - to show disk speed ).
The permissions are stored in the "sudoers" file (on Linux in /etc/sudoers).
http://www.sudo.ws/sudo/man/sudoers.html
Some convenient commands for Linux
I have created a file /etc/profile.d/aliases.sh This file is sourced by /etc/profile - look inside for this code: |
chkconfig - command to configure things to start on reboot. chkconfig sendmail on to look at the status: the output of the last command: |
Crontab - a command to schedule jobs. Each user has a separate crontab. A crontab file contains instructions to the cron daemon. Commands in any given crontab are executed as the user who owns it and using environment of /bin/sh. export EDITOR=vi The cron file may contain comments (start with #) or active lines with 6 space-separated fields - minute hour day month weekday command. Asterisks (*) specify when commands are to be run in every instance of the value of the field. For instance, an asterisk in the Month field would mean that the command should be run every month. In addition, multiple events can be scheduled within a field by separating all instances with commas - with no space between. Here are some examples of scheduling: 0 0 * * * -- midnight every day Example of the whole file: # ################################################# More examples Crontab starts with "sh" shell. So usually it is a good idea to invoke bash, /usr/bin/bash -c ' source envfile; $PERL $WRAPPER some_executable some_options --dt=$JDSCRONDT >> $logdir/logname_${JDSCRONDATE}.txt 2>&1' two methods to remove old files: |
To have the date on your server synced automatically, ask admins to set up ntpd / ntpdate so that the time is automatically maintained. To do this just set up a cron job as root like this: 1 * * * * /usr/sbin/ntpdate -s time.apple.com This will sync time with the apple timeserver every hour. If you don't have auto-sync set up as described above and just need to set the date manually, simply do the date command without option, take the output, change it to your liking - and then feed it to a date command with "-s" option, for example: date -s "Mon Nov 29 09:31:00 EST 2004" |
DNS related commands: nslookup, dig, host nslookup www.LevSelector.com ns18.zoneedit.com Example: looking for MX or SOA record: host iguanahelp.com |
vsftp: ps auxw | grep ftp Edit the config file: The standard log is here: Documentation is here How to set up a directory for only ftp access: |
to add a new user: Note: Never make password the same as login - there are common attacks
which exploit this security hole. to remove a user: To create a new group: groupmod - modify (rename, etc.) the group chmod user:group filename Commands to see user and groups: |
Here is how to see the info about your unix box: uname -a cd /etc/httpd/conf - here are web configs To see what's going on: |
To reboot the computer remotely, become root and issue the command "reboot". |
Common security threats exploiting commands wget and curl. You can greatly reduce the risk by removing run privileges from users others than root, for example: chmod 750 /usr/bin/wget |
How to start IPs: then do: |
-- -- more commands (random flow) -- --