cat .ssh/id_rsa.pub | ssh 111.122.1.98 "cd;mkdir .ssh;cat >> .ssh/authorized_keys; chmod 600 .ssh/authorized_keys"

I haven't been writing anything here for three years now. It's a long time. Having reviewed some of the posts from 2008 and 2009 I find that's useful rereading what I have myself written before. Some of the knowledge didn't make into a long-term memory :-)

 Anyway, for today I discovered a new option for yum repository configuration files.
 includepkgs  This is a list of packages you want to use from a repository. If this option lists only one package then that is all yum will ever see from the repository.
This is useful if you want to add external repository because of only one package.

 exclude
excludes packages listed.
e.g. exclude=eclipse* kernel
This option is useful if you have a conflict among different packages in your repositories.

Note that if you have multiple exclude configuration lines, only the last one will be valid.
Same is true for any other configuration lines in yum.conf.
This is a limitation of yum, though not a huge one. Postfix, nagios can have multiple lines and they are all valid. Say, in nagios you can have as many configuration directories as you want. And all are valid:

cfg_dir=/etc/nagios/cfgs

cfg_dir=/usr/local/nagios/etc-common

cat .ssh/id_rsa.pub | ssh 111.122.1.98 "cd;mkdir .ssh;cat >> .ssh/authorized_keys; chmod 600 .ssh/authorized_keys"

find . -type f -print0|xargs -0 ls -s1|sort -rn|head

tr -cs "[:alpha:]" "\n" < bool2.pl |tail -10

modprobe -r pcspkr ---switch off pc speaker

vim: %&g --repeat last substitution everywhere in the file

dmesg|dd -conv ucase

vim: :s ---repeat last substitution. Or simply &

tar cf - old-dir |(cd new-dir; cd ..; tar xvpf -)

vim: :%s/Intel/\U&/gc

vi: %s/^=.*=/=&=/gc ----lowers all headers level in wikipedia by one.

ex: 3,8s/.*/(&)

tar xvf my.tar `tar tf my.tar|grep 'pattern';sleep 60`

:%s/\(abcd)\1/alphabet-soup/ ----changes 'abcdabcd' into 'alphabet-soup'

ex: :s/End.*/End ---removes all characters on the line after 'End'

cd; find . -print|tar cvf /dev/rmt/0cbn -T -

vim: :g/3/s/line/LINE/gc ---on lines containing '3' substitute 'line' by 'LINE'

screen -D -R

cat /proc/cmdline ---shows parameteres passed to the kernel during boot

man 7 signal

ex: 164,220 ya a ---yank lines 164 through 220 into buffer a. pu a ----put buffer a.

vim: % refers to the current filename, # - to the alternate filename. :w %.new ^^

vim: :e! ---discard edits and return to the saved version of the current file.

find . -print|cpio -oacvB|(ssh myhost dd of=backup.file bs=5120

dmesg|grep cpu. -io

vim: :args :last :rewind

dpkg -iG foo ---G says not to proceed if a newer package is already installed.

ext: tune2fs -l /dev/hda2

vim: :0r foo.txt :$r foo.txt :$185 foo.txt :/pattern/r foo.txt ---place contents of foo.txt in the beggining, end, after line 185 or after first linke with 'pattern' accordingly.

`usermod -L` locks the user, `usermod -U` unlocks

gpg --keyserver=x-hkp://pgp.mit.edu --send-keys e4eac24b

df . ---quickly determine what filesystem the current directory is in.

virtualization-capable CPU (/proc/cpuinfo) must have a flag SVM (for AMD) or VMX (for Intel)

etherpad.com

ex: g/pattern1 ---print all lines containing pattern1

ex: /pattern1/;+5 ---print the first line containing pattern1 and 5 lines following it.

audit2allow -i /var/log/audit/audit.log

chcon -R -t httpd_user_content_t /var/www/

yum install postfix system-switch-mail

ex: 5,+5 --prints lines 5 through to current line +5. It can cause an error if the current line has a number less than the first line in range. 5;+5 with ; instead of , makes the end relative. ie it will be calculated from the first line of range.

ex: /foo/,/bar/d ---delete lines starting with the first occurance of foo through to the nex occurance of bar

ex: /gaga/+d ---delete a line below the first line containing 'gaga'. It is the same as /gaga/+1d

IPADDR_START ..

/etc/sysconfig/network-scripts/ifcfg-eth0-range0
IPADDR_START=192.168.0.100
IPADDR_END=192.168.0.200
CLONENUM_START=1 ---it can be any number. The devices will be numbered starting from it, e.g. if CLONENUM_START=5, then the first will be eth0:5.

~/.bash_profile: export EDITOR=vim; export VISUAL=vim; export PAGER=LESS

expand -i -t 18

ex: ,/gaga/d ---delete current line through to the next line containing 'gaga'

ex: /gaga/d ---delete next line containing gaga

ex: -,+t0 ---copy three lines (the line above the cursor through the line below the cursor) and put them at the top of the file.

mke2fs -t ext4 -O ^has_journal /dev/sdf -L sysrescuecd

grub-install --root-directory=/media/usbstick/ /dev/sdf

touch /forcefsck or `shutdown -rF now` ---the -F option forces fsck on reboot

no sound in skype with pulseaudio: pavucontrol

ex: ,+5# ---shows line numbers of 5 lines starting from the current one, ,+ 5# --with a space between + and the number, shows file numbers of current AND 5 following lines, i.e. 6 lines in total; +5# ---without comma in front, is not a range and will operate on exatly one line, the fifth from the current one

ex: .,+203# or ,+203 (dot can be ommitted, because it is presumed when + is used) --display line numbers from the current line to 203 lines further

ex: 500,$m.-2 ---move lines from 500 through the end of the file to two lines above the current line

httpd.conf: AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css application/javascript application/x-javascript ---enables compression ..

http://www.gidnetwork.com/tools/gzip-test.php

service httpd configtest

yum.conf: metadata_expire=90m

rpmbuild --showrc

ex: .,.+32d ----delete 32 lines starting from the current one

syslogd -a /var/named/chroot/dev/log

man bootparam

man capabilities

dnssec-keygen -a hmac-md5 -b 256 -n USER dyndns --> in the global part of named.conf add key dyndns { algorithm HMAC-MD5; secret "Qoeuoaeu";}; --> for each zone that you want to have dynamic updates write 'allow-update {key dyndns; };'

xsetroot -solid black

rpm --checksig; rpm -K

dhcpd.conf: shared-network {subnet {group { host }}}}

ex: %d ---delete all lines in a file

ex: 23,.m$ --move lines from 23 to the current line to the end of the file

pinfo

man -aw ls

man -d ls

when you get segmentation fault in yum: rm -f /var/lib/rpm/__db*; rpm --rebuilddb

xorg.conf is missing: Xorg -configure :1

ex: := prints the total number of lines; :.= prints the line number of the current line.

ex: 1,10# --display lines 1 to 10 and their respective numbers; se nu; se nonu

for i in {0..110};do echo line $i;done

`xmonad --recompile` ---same as alt-q when xmonad is running, but does not require even X11 to be running.

prevent overwrite of existing files: set -o noclobber; disable with `set +o noclobber`

dd if=8.0-RELEASE-amd64-memstick.img of=/dev/da0 bs=10240 conv=sync

tcpdump -i any

fedora installation mounts: /mnt/sysimage; /mnt/isodir

nt: fsutil file createnew swap_device 536870912

distro upgrade: apt-get dist-upgrade; fedora: preupgrade

bash: repeat a command that contained foo ANYWHERE in the line: !?foo; repeat a command that contained foo IN THE BEGINNING of a line : !foo; ^ma^pa executes THE LAST command replacing FIRST occurance of 'ma' with 'pa'

.bashrc: HISTFILE="~/.bash_history; HISTSIZE=10000

yum groupinstall "Moblin Desktop Environment"

vim: "1pu.u.u.u

winecfg; wine control; winefile; wine uninstaller; wine foo.exe

ports: dhcpd listens on UDP:67 and answers using UDP:68

screen /dev/ttyS0

use output of one command as an argument of another: rm -i $(find -iname *.mp3)

reboot system every time user connects to the system. The user will not be able to run any commands. ~/.ssh/authorized_keys: no-port-forwarding,command="/sbin/reboot",no-pty ssh-rsa AB...YZ

yum install yum-presto

grep 'a b' 44 ..

user@system3:/tmp$grep 'a
> b' 44
aa bb
aabb
user@system3:/tmp$grep 'ab' 44
aabb
user@system3:/tmp$grep 'a b' 44
aa bb
user@system3:/tmp$sudo -i^C
user@system3:/tmp$cat 44
aa bb
aabb

open file on the last line: vim + /var/log/messages; less +G /var/log/messages

mysql_install_db --user=mysql; mysql_secure_installation

Things to take with when going out:

Contact Phone numbers, address and map, keys or whatever is required to get in
Warm jacket
Rescuecd, rescueusb
Laptop with tftpd, dhcpd
3g modem
Cable cat5 cross
cable com-to-usb
Screwdriver
RSA keys
presents
more business cards than usual
phone friends to tell you will be around

chkconfig nscd on; nscd -i hosts; ipconfig /flushdns

for i in {1..19}; do echo $i; done

PS1="\u@\h:\w\$"

query rpm with the specified m5sum: rpm --fileid neededmd5sum

output and error redirection: myprogram 1>messages.out 2>messages.err ; myprogram &>both or myprogram >&both which is the same

check the openssl on local port 995: openssl s_client -connect localhost:995

view changes to default configuration: dovecot -n; postfix -n

escape characters: ^] for telnet; ^A for GNU Screen; ^B for tmux

rpm --nomd5 --nopgp

list package requerements: rpm -qR bash

list only documentation files of a package: rpm -qd bash

list only configuration files of a package: rpm -qc bash

remove package: rpm -e glibc-devel

force installation: rpm -i foo.rpm --nodeps

freshen file (do not install if such package is not installed on the system): rpm -F *.rpm. however it does not resolve dependencies

install foreign package: alien -i package.rpm

simulate package installation: apt-get -s; rpm --test

download, but do not install: apt-get -d

list all installed packages, or in the example only bash: dpkg -l bash; rpm -qa bash

list files in a package: dpkg -L pkg_name

gzip -dc tarball.tar.gz|tar -xv ---option -c of gzip says not to delete the old file

mysql: /etc/my.cnf: skip-networking

which package owns the file: rpm -qf /file ; pacman -Qo /file; dpkg -S file; r

ssh: ssh-copy-id user@target-machine

C: .c -> preprocessing (including files, etc) .i -> translating to assembler .s -> converting to machine code .o -> linking .exe --- gcc --save-temps

vim: c/phrase_down_to_which_change ---combine search with change

quota: apt-get install quota quotatool; vim /etc/fstab ---add to options grpquota,usrquota; touch /opt/.quota.user /opt/.quota.group; chmod 600 /opt/.quota*; mount -o remount /opt; quotacheck -avugm

asterisk: asterisk -cvvv ---if you don't have startup files for asterisk, or don't want it to start at boot

asterisk: asterisk -rvvv: module reload chan_sip; module reload chan_iax2; dialplan reload; dnsmgr reload; ael reload ---reloads extensions; reload ---reloads all

selinux: touch /.autorelabel;reboot --- if you can't use iptables or sth else due to wrong selinux permissions (due to a bug)

yum grouplist; yum groupinfo "development tools"

rpm: rpm --root root_directory -vv

rpm: rpm --showrc; /usr/lib/rmp/rpmrc ---default global configuration file; /etc/rpmrc; ~/.rpmrc

selinux: setsebool -P allow_httpd_anon_write=1 ..

SHARING FILES
If you want to share files with multiple domains (Apache, FTP, rsync,
Samba), you can set a file context of public_content_t and public_con-
tent_rw_t. These context allow any of the above domains to read the
content. If you want a particular domain to write to the public_con-
tent_rw_t domain, you must set the appropriate boolean.
allow_DOMAIN_anon_write. So for httpd you would execute:

setsebool -P allow_httpd_anon_write=1

selinux: selinux port -l

selinux: semanage port -a -p udp -t ssh_port_t 115

postmap /etc/aliases ---after editing the file

postconf alias_maps

getent passwd sergey; getent group wheel

ssh-agent screen ; ssh-agent startx

bash: eval `ssh-agent`

awk 'END {print NR }' /etc/group ---shows the number of the last line in the file

# awk 'END {print NR }' /etc/group
80
# wc /etc/group
80 80 1150 /etc/group

awk -F: '{if ($4 && $4!=$1) print $1}' /etc/group

bash: enable -a ---shows enables built-in commands; enable -n cd ---turns off built-in cd

nt: ipconfig /displaydns |more ; ipconfig /flushdns

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services|Dnscache\Parameters
DWORD:MaxCacheEntryTtlLimit
Value:14400 ---this is in seconds. 14400 is 4 hours.

hostapd.conf ..

/etc/hostapd.conf:
interface=ath0
bridge=br0
driver=madwifi //generic linux driver is wext
debug=0
ssid=my-net
macaddr_acl=0
auth_algs=3
wpa=1
wpa_psk_file==eth/hostapd_wpa_psk
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP


/etc/hostapd_wpa_psk:
00:00:00:00:00:00 password_for_any_client //all zeros direct to accept all MAC addresses.
11:22:33:44:55:66 waylongpassword
10:20:30:40:50:60 another_password_for_another_client


/etc/wpa_supplicant.conf:
network={
ssid="my-net"
psk="waylongpassword" //it takes time to compute it each time. To save that time use wpa_password to encrypt passphrase, and then copy result into place
pairwise=CCMP //much stronger than RC4 that is default WEP
group=CCMP
ky_mgmt=WPA-PSK

wpa_supplicant -iath0 -c/etc/wpa_supplicant.conf -Dmadwifi -w
to make it permanent on debian and call wpa_supplicant automatically:
/etc/network/interfaces:
auto ath0
iface ath0 inet dhcp
pre-up wpa_supplacant -iath0 -Dmadwifi -Bw -c/etc/wpa_supplicant/wpa_supplicant.conf
post-down killall -q wpa_supplicant

ifcfg-eth: ..

DEVICE=eth
ONBOOT=yes
BOOTPROTO=dhcp
HWADDR=11.22.33.44.55.66
DHCP_HOSTNAME=sergey
TYPE=wireless
PEERDNS=yes
MODE=managed
RATE=auto

dhclient.conf: send-hostname "sergey"

send-hostname "sergey"

slaptest

openssl rsa -in slapd-key -pubout>slapd-key.out

awk -F: '{print $1}' /etc/passwd ---the same as cut -f1 -d: /etc/passwd

arptables, ebtables (for ethernet), iptables (for ip), squid (http)

wireless bridge configuration: /etc/network/interfaces ..

auto lo
iface lo inet loopback

auto br0
iface br0 inet static
address 192.168.1.0
network 192.168.1.0
netmask 255.255.255.0
broadcast 192.168.1.255
bridge_ports ath0 eth0
post-down wlanconfig ath0 destroy
pre-up wlanconfig ath9 create wlandev wifi0 wlanmode ap
pre-up iwconfig ath0 essid "alrac-net" channel 01 rate auto
pre-up ifconfig ath0 up
pre-up sleep 3

ls -d .* ---list only hidden files

ls -L ---show i on the linked file, rather than the symbolic link itself

ls -1 ---show only 1 file per line

ls -S ---sort by size

ls -Q ---quote names (GNU extension);

sed: sed '1 i this is first line' file ---adds line 'this is the first line' to the beginning; sed '$ a this is last line' file

mysql postinstall: set password for root@localhost=password('secret'); delete form mysql.user where user=''; delete from mysql.db where user=''..

Grant select on *.*to sergey@localhost identified by'secret';
OR
grant all on db1.*to serega@localhost identified by 'great_secret';

mysql: select user,host from mysql.user;

mysql: mysqladmin -u root shutdown

slapd.conf: loglevel 296 --- -1 all loging information, 0 - no logging i, 1-trace function calls; 2 -packet handling debugging i; 4- heavy trace deb..

8 - connection management
32 -search filter processing
64 - configuration file processing
128 - access control list processing
256 - statistics for connection, operations, and results
512 - statistics for results returned to clients
1024 - communication with shell backends
2048 - print entry debug information

All i is loggedusing the LOG_LEVEL4 syslog facility.
Add the following to /etc/rsyslog.conf and killall -HUP syslogd
local4.debug /var/log/slapd.log

postfix: postconf -e "mynetworks = 192.168.1.0/24, 127.0.0.1/8"

host -t mx mail.ru

postfix: postconf -e "relayhost = mailhub.example.com" -- the changes take force immediately

mutt: set folder="imaps://username@example.com" set spoolfile="imaps://username@example.com/INBOX" If you don’t feel like typing in your password every time you can also put it there: set imap_pass="mypassword" Also, my favorite line which disables that annoying Mutt prompt that asks if you want to move the read mail messages: set mbox="!"

ssh: Host is anything and hostname is the real name

Host Short_Name
HostName some_host.com
User domain\username
Protocol 2
UseRsh no
IdentityFile ~/.ssh/KEY

mdadm --create --verbose /dev/md1 --level=6 --raid-devices=4 /dev/sda2 /dev/sdb2 missing missing

apache: openssl rsa -in out.key -out out.key --strip the password, i.e. if take password-protected key and get rid of password protection.

ssl: openssl genrsa -des3 -out out.key 4096 &&openssl req -new -key out.key -out out.csr

apache: yum install mod_ssl

sendmail: define(RELAY_HOST, foobar.com)

apache: htpasswd -c /etc/httpd/htpasswd admin

apache: service httpd configtest

vi: e! ---reread the file losing all unsaved edits

bash -n ---parse for syntax errors. No commands are actually executed

sh: bash -x --show lines to be executed prior to their execution; -u --generate an error when Undefined variable is used.

sh: while : ; do echo "haha haha haha..."; sleep 1;done

stty -a

zsh -fx ---start a clean version of zsh (without startup files)

bootparam: init=/bin/bash rw

/etc/inittab: s1:12345:respawn:/sbin/agetty 19200 ttyS0 vt100 ---enable login through serial console

bootparam: console=ttySo,19200n81 ---redirects boot messages to COM1

echo 'Subject: Hey, ss!' |/usr/lib/sendmail -v gaby@gmail.com

sh: b=${a/23/BB} ---assign b the value of a, where all occurances of 23 are substituted with BB

vim: CTRL-@ insert previously inserted text and stop Insert mode

vim: i_CTRL-R {0-9a-z%#:.-="} insert the contents of a register

exportfs -ar

stty -a

stty erase ^h --- ^\? for DELETE key

vim: i_CTRL-A ---insert previously inserted text; i_CTRL-@| CTRL-@ ---insert previously inserted text and stop

sh: $HISTFILE, $HISTSIZE

rsync -vaze ssh --delete /www/ $dest_ip:/www --progress --bwlimit=1 ||echo "rsync failed"| mail admin@me.com ---note slash at the end of /www/ ..

It makes it be ragarded as the target rather than subdir /www/www
bwlimit default is in KB/sec

vim: `<[ ---go to the start of the (previous) Visual area

vim: `[ --- go to the start of the previously operated or put text

vim: `quote `" ---go to the position when last editing this file

vim: `0 ---go to position where vim previously exited.

rm -- '-foo'

sh: set -o ignoreeof ; csh: set ignoreeof

hardware flow control uses dedicated signal wires such as RTS/CTS or DTR/DSR while software flow control signals by sending DC1 or DC3 control bytes..

in the normal data wires. For hardware flow control, the cable must be correctly wired.

mkisofs -r -b boot.img -c /boot/boot.catalog -o /tmp/cd.image; cdrecord -scanbus; cdrecord -v de=1,0,0 -data /tmp/cd.image ---the boot.catalog file ..

need not already exist. It is generated by mkisofs. The command linke optien just tells mkisofs where in the image to store the generated file.

pwconv, pwunconv, grpconv, grpunconv ---/etc/passwd /etc/group /etc/shadow /etc/gshadow

pgrep -vlU root,bubba ---show processes NOT owned by root or bubba

host -t mx google.com

squid: iptables -A PREROUTING -t nat -i eth3 -p tcp --dport 80 -j REDIRECT --to-port 3128.

vncserver; vncviewer :1 ---for port 5001, vncviewer :2 ---for port 5002; vncserver --kill :1

xsetroot -solid blue

passive ftp: iptables -A INPUT -i eth0 -p tcp -s any/0 --sport 1024:65535 -d $my_ip --dport 1024:65535 -j ACCEPT

allow ftp: iptables -A INPUT -p tcp -s any/0 --sport 1024:65535 -d $my_ip --dport {21;20} -j ACCEPT;

mysqld_safe --skip-grant-tables; mysql -u root; update mysql.user set password=password('new_password') where user='root'; flush privilages

cat /etc/passwd|mksmbpasswd.sh>/etc/samba/smbpasswd ----adds users, but passwords must be set seperately with smbpasswd

hosts.allow for nfs: portmap,lockd,mountd,rquotad,statd.

portmap:192.168.0. 192.168.1. .example.com

the order of starting nfs servers: portmap, nfsd, mountd, statd, rquotad, idmapd, svcgssd.

bootparam(7): (root,nfsroot,ro,rw,debug,init) -> particular device?? -> environment variable ?? -> argument to process 1

The Argument List
The kernel command line is parsed into a list of strings (boot arguments) separated by spaces. Most of the boot args take the form of:

name[=value_1][,value_2]...[,value_10]

where 'name' is a unique keyword that is used to identify what part of the kernel the associated values (if any) are to be given to. Note the limit of 10 is
real, as the present code only handles 10 comma separated parameters per keyword. (However, you can re-use the same keyword with up to an additional 10
parameters in unusually complicated situations, assuming the setup function supports it.)

Most of the sorting goes on in linux/init/main.c. First, the kernel checks to see if the argument is any of the special arguments 'root=', 'nfsroot=',
'nfsaddrs=', 'ro', 'rw', 'debug' or 'init'. The meaning of these special arguments is described below.

Then it walks a list of setup functions (contained in the bootsetups array) to see if the specified argument string (such as 'foo') has been associated with
a setup function ('foo_setup()') for a particular device or part of the kernel. If you passed the kernel the line foo=3,4,5,6 then the kernel would search
the bootsetups array to see if 'foo' was registered. If it was, then it would call the setup function associated with 'foo' (foo_setup()) and hand it the
arguments 3, 4, 5 and 6 as given on the kernel command line.

Anything of the form 'foo=bar' that is not accepted as a setup function as described above is then interpreted as an environment variable to be set. A (use‐
less?) example would be to use 'TERM=vt100' as a boot argument.

Any remaining arguments that were not picked up by the kernel and were not interpreted as environment variables are then passed onto process one, which is
usually the init program. The most common argument that is passed to the init process is the word 'single' which instructs init to boot the computer in sin‐
gle user mode, and not launch all the usual daemons. Check the manual page for the version of init installed on your system to see what arguments it
accepts.

bootparam(7): 'nosmp' and 'maxcpus=N' (Only when __SMP__ is defined.) 'nosmp' or 'maxcpus=0' will disable SMP.

bootparam(7): 'panic=N' By default the kernel will not reboot after a panic, but this option will cause a kernel reboot after N seconds

irssi: /channel add -auto #vimperator Freenode

irssi: /network add Freenode irc.freenode.net 6667

$ pv /dev/zero > /dev/null

$ tar -cf - /path/to/dir | pv | nc -l -p 6666 -q 5

$ tar -cf - . | pv -s $(du -sb . | awk '{print $1}') | gzip > out.tgz

SSH: The escape character (default ~)is only recognized at the beginning of a line. '~.' --close connection, ~~ --send '~', ~C-Z --suspend

GNU screen: C-A G ----disables audible bell.

I did not understand that visual bell is a 'feature'. I thought it was a bug. It was the only reason why I did not make a full use of GNU Screen. Now I know.
In xterm the default should be no visual bell. However, you can use `xterm +vb` to explicitely disable it.
In my case visual bell was enabled in /etc/screenrc.
What is interesting, is that any user changes behaviour of all users, of the whole system.

An analogy of MS/Apple/Linux users came to my mind. Its like wearing clothes. Windows is a warehouse, noname. Mac is a brand like Stones, D&G, Kevin K

lein. Linux is a radioshack. It is a source code. It is materilal from which you can build your own style. Every linux user is different.
Yet another analogy. Cooking food. Mac is a restaurant, Win is junk food (McDonalds), Linux is cook at home (including 'heat this in microwave oven for 3 min and eat').

The word 'linux' can be substituted by {Open,Free,Net,DragonFly}BSD or any other open source project.

less: ESC-u ---syntax highlighting on/off switcher

sniffit -p25 -t machine2 ----hoeren komplette Mailverkehr eines Rechners (Port 25) namens machine2 ab.

"Phreaking wasn't about getting free calls, it was about _how_ to get them, _how_ to make them. It was about the process of _access_. Legend had it ..

that the first phreaks were blind kids who wistled free calls, tuning in to the sounds of the first vast machines and places they could never see. The phreak was to discover and master invisible electronic worlds.
Phreaks routinely complained about evil, monopolistir Ma Bell, but to understand the machine, the network, the telephone system - these were the true goals of the phreaks, a journey that would eventually lead to a better understanding of the world. The first computer hackers brought light to a closed world. Early computers were giant, cumbersome machines tended by priesthood of technicians who processed punch cards, maintained massive air-cooling systems, and replaced the occasional melted vacuum tube.
The first hackers challenged the authority of priesthood and began nudging the computers to life, teaching them to play chess, Ping-Pong, even musir. The cleverly removed superfluous commands so computers would need fewer cards. Hackers at MIT toured telephone central offices and pumped switchmen and engineers for the secrets that would enable them to ride the telephone network for free. They studied lock picking to coax open university doors to examine the computers up close (p11-12)

abbr: AUI - Attachment User Interface - in ethernet

ethernet (802.3) was standarized in 1978 by Xerox, Intel and DEC

type ls

/ —move Back/Forward in the current window/tab's history, respectively Move between tabs using these keystrokes which may also be familiar to tabbing Vimmers. gt/ — go to the next tab gT/ — go to the previous tab g0/g$ — go to the first/last tab d — close the active tab (delete the buffer)

secure mount points: nodev, nesuid,ro,noexec. Noexec is of little use, because it can be easily bypassed by using /lib/ld-linux.so to execute binaries

chroot will not run on such system, because /dev/null and /dev/log

Both 802.11a and 802.11g support speeds up to 54Mbps. Primary difference is supported spectrum. 802.11a operates in 5.0GHz while 802.11g in 2.4GHz.

freqency assignments for 2.4GHz Band: 2.412 2.417 2.422 2.427 2.232 2.437 2.442 2.447 2.452 2.457 2.462 2.467 2.472

If you have to use Windows when scanning wireless networks disable TCP/IP stack, on Windows CE set nonstandard IP and subnet mask and gateway.

~/.xsession is for XDM, ~/.xinitrc is for startx.

I am sitting in front of apollo and launch programs on zeus without SSH: xhost +zeus; export DISPLAY=apollo:0.0.; after you are done type xhost -zeus.

SSH can forward X connections and there's no need for the above steps

GDM: to enable network connections change DisallowTCP=true to DisallowTCP=false
KDM or XDM: both on settings in the Xservers file. Look for a line that begins with :0. This line contains a command that KDM or XDM uses to launch the X server. If this line contains the string -nolisten tcp, remove that string from the line.
X launched from text-mode login: if you log in using text mode and type startx to launch X, you may need to modify the startx script itself, which is usually stored in /usr/bin. Search this script for a string -nolisten tcp. Chances are this string will appear in a variable assignment (such as defaultserverargs) or possibly in a direct call to the X server program. Get rid of the string.
SSH: /etc/ssh_config set ForwardX11 to yes, /etc/sshd_config set X11Forwarding to yes.

X clients are the programs that users run - xterm, xfontsel, Kmail, OpenOffice.org etc.

.Xresources is cousulted when the window manager starts up, whereas .Xdefaults can be used at any time. The format is 'ProgramName*ResourceName:Value'

XTerm*Background: linen
XTerm*Foreground: black
XTerm*Font: 9x15
XTerm*saveLines: 1000
XTerm*geometry: +50+100

Irrespective which start script you use (.xsession, .xinitrc or .Xclients) it must be executable. chmod u+x .xinitrc

[ file1 -ef file2 ] file 1 and file2 have the same inode and device numbers, -nt newer than, -ot older than man test

[ integer1 -ne integer2 ] integer1 not equal integer2

[ -L file ] checks whether file is a symbolic link

-r the user read permissions, -w the user has write permissions, -x the user has execute permissions, -s the size is greater than 0, -z is null

test -f badfile; echo $? or [ -f badfile ]; echo $? -d is a directory, -e exists, -f regular file, -n is not null

cat << theend

2>&1 -- redirect stderr to the same file to which stdout is redirected

ls file1 file2 file3 1>>ls.out 2>>ls.err

SCSI (X3.131-1986), now usually called SCSI-1. This standard has now been withdrawn. Up to 8 devices on a cable, passive termination, 8bits/ch 5MB/sec

The SCSI standard was designed for disks, but is very flexible and was used for other devices, notably scanners and slower devices such as Zip.
FCconnection used a 50 connector cable, originally with Centronics connector, but later with a 50-pin D-shell connector, similal to a DB-25 RS-232 serial connector.

RH: sndconfig

lsmod|egrep '(snd)|(Module)'

cat /proc/modules

MIDI port (MPU-401). Many sound cards have an interface to attach MIDI (Musical Instrument Digital Interface) device. MPU-401 ISA interface 0200-020F

CTS - clear to send, RTS - ready to send

dial connections: kppp, wvdial (command line), system-config-network

UART is a Universal Asynchronous Receiver Transmitter

setserial: the -G option prints the output in a format suitable for use in setting parameters with serial.

The keyboard/mouse controllel uses ports 0060 and 0064 for legacy (PS2) keyboards and mice.

If your system has legacy floppy disk controller, it will use ports 3F0-3F7

EPP stands for Enhanced Parallel port and is designed for devices such as CD-ROMs and tape drives which require large amnts of i to flow in either way

ECP stands for Enhanced capabilites port and is designed for use with printers.

Standard parallel port assignments: LPT1 378-37F 7; LPT2 278-27F 5; LP* 3BC-3BE _.

Many systems do not use interrupts for printers, so the IRQ may or may not actually be used.
It is not also uncommon to share IRQs for printing and also share IRQ 7 with a sound card (Sound Blaster compatible)
ECP stands for Enhanced capabilites port and is designed for use with printers.
EPP stands for Enhanced Parallel port and is designed for devices such as CD-ROMs and tape drives which require large amounts of information to flow in either direction.

standard IO and IRQ for serial ports: COM1 3F-3FF 4 ; COM2 2F8-2FF 3; COM3 3E8-3EF 4; COM4 2E8-2EF 3

cat /var/log/messages.log|grep "[hs]d[a-z]"

setxkbmap -option ctrl:nocaps

setxkbmap -layout "us(dvorak),ru" -option "grp:menu_toggle"

gpg -c letter.txt ----encrypt with a prompted password instead of your key. To read: gpg letter,gpg

f

gpg -es letter.txt receiver -u my_identity ----sign and then encrypt

g

gpg -sta message.txt -----use CLEARSIG feature: do not compress, apply signature in printable form in the end of the file.

gpg -s letter.txt -u Sergey

.

gpg -e letter.txt Alice Bob Carl

mysql: mysql -u test

mysql: select version();

mysqladmin -u root -p 'new_password'

" "- weak quoting, ' ' - strong quoting

$VISUAL is a full-screen editor, and $EDITOR - a line editor. The shell first tries $VISUAL, then $EDITOR

"Block mode" in terminalsthe characters you type are temporarily retained in the terminal memory (and may possibly be edited by a built-in editor at

"Block mode" in terminalsthe characters you type are temporarily retained in the terminal memory (and may possibly be edited by a built-in editor at the terminal). Then when the send key is pressed, a block of characters (sometimes just a line of characters) is send to the computer all at once. Block mode is not supported in Linux.

VDT - video display terminal

SQL does not assign unique identifiers to rows, so it is possible to have several completely identical rows in a table

SCTP (Stream Control Transmission Protocol) has higher reliability than TCP, and at the same time lower overhead from protocol headers.

RFC 3268 - An Introduction to the Stream Control Transmission Protocol
RFC 2960 - Stream Control Transmission Protocol

less and more is the same program in OpenBSD, and behaves differently depending on which way it was called

PnP: there is no one program that would handle PnP in Linux. Each device driver has its own PnP, using sw supplied by the kernel. The BIOS does PnP wh

en a PC is first powered up.

find /etc -name '*e*' -size +1k -size -1m

The wildcard must be enclosed in the quotes in order to protect it from expansion by the shell.

GIMP: image ->duplicate CTRL-D

The extent size is the same for all volumes in the volume group. The volume group maps the logical extents to physical extents.

LVM: Within a physical volume extents are refered to as physical extents, within a logical volume - as logical extents. The extent size is the same for all volumes in the volume group. The volume group maps the logical extents to physical extents.

man hier

turn off the WEP key to accept unencrypted packets when scanning: iwconfig wlan0 key off

set essid to "off" or "any" when scanning for 802.11 networks, e.g. iwconfig wlan0 essid off

make a pdf of a manual page: man -t iwconfig - > iwconfig.pdf

vim: i_CTRL-A --insert previously inserted text, i_CTRL-@ - insert previously inserted text and stop insert

GIMP: you can tear-off any context menu

x:5:once:/bin/su user0 -c "/bin/bash --login -c startx >/dev/null 2>&1"

Starting X as preferred user without logging in

A way of circumventing display managers and boot straight into preferred window manager or desktop environment is the following.
In /etc/inittab change:

id:3:initdefault:

[...]

x:5:respawn:/usr/bin/xdm -nodaemon

to

id:5:initdefault:

[...]

x:5:once:/bin/su PREFERED_USER -l -c "/bin/bash --login -c startx >/dev/null 2>&1"

whatismyip: curl -s myip.dk |grep ‘”Box”‘ | egrep -o ‘[0-9.]+’

Finding out your PC’s IP in Linux is a simple matter of typing ifconfig in a Terminal shell. But what if you’re behind a router? Thanks to a simple shell script, you can display your IP in the command line by simply invoking the whatismyip command.

#!/bin/bash
curl -s myip.dk |grep ‘”Box”‘ | egrep -o ‘[0-9.]+’

sudo chmod +x /usr/bin/whatismyip

rankmirrors - choose the best mirror

Archlinux:
cd /etc/pacman.d/; cp mirrorlist mirrorlist_backup; rankmirrors -n 6 mirrorlist_backup>mirrorlist
Or simply manually put the best servers on top of mirrorlist.

Цитата #9601 de 3txt_iBash.Org.Ru xxx: Вчера я наконец понял, зачем в тюнингованных девятках ставят кучу датчиков на панель! xxx: Это все дебагеры

choosing secure password

The goal is to create easy to remember, convertible and secure passwords, so that you can be sure, that only YOU control what goes into and comes out of your different accounts.

This is an approach, you should try: Build passwords using two parts:

* the strong static part with at least 8 characters and
* the changeable part to remember the purpose of the usage


Let’s start with the Static Part:

You can make a password much more secure by mixing different types of characters. Use some uppercase letters along with lowercase letters, numbers and even special characters such as '!' or ';'. Very important is that you have to find a good way to remember it. A good way to do this is to choose the first letters of a sentence that you will remember.

e.g.

Every morning at 7; I kiss my Honey! Ema7;IkmH!
Brayn Adams - Back in the summer of '69 BA-Bitso69


The Changeable Part:

Try to find short terms for the different uses.

e.g.

Hotmail Account hot1 or hot2
Ebay Account ebay or ey
Bank Account
city or cy
My Blog
blog or bg



That’s it! “Glue” both parts together and you have nice passwords for different purposes that you can easily remember.

My bank account: cyEma7;IkmH!
My mail password: hot1Ema7;IkmH!

pacman -Qe (lists explicitely installed packages)

~/.Xresources: *dpi:75 XTerm*background: black XTerm*foreground: green

*dpi:75
XTerm*background: black
XTerm*foreground: green
XTerm*visualBell: false

vim windows: z{height} - change height of the window CTRL-W _ - maximize window CTRL-W CTRL-W - change window

z{height} - change height of the window
CTRL-W _ - maximize window
CTRL-W CTRL-W - change window

vim: zt, z., zb, z{height}

zt - show current line in the center of the screen
z. - ~ in the center
zb - ~ in the bottom

setting dvorak

loadkeys dvorak/dvorak

To make this change permanent, set

KEYMAP=dvorak/dvorak

in /etc/rc.conf.

To convert to dvorak in X, type

setxkbmap dvorak

To make this change permanent, set

Option "XkbLayout" "dvorak"

in the keyboard "InputDevice" section of /etc/X11/XF86Config or /etc/X11/xorg.conf.

If you are using the input hotplugging (evdev) you'll need to make the following changes:

cp /usr/share/hal/fdi/policy/10osvendor/10-keymap.fdi /etc/hal/fdi/policy/

Edit the resulting file and update the input.xkb.variant entry to look like:

dvorak

Lastly you'll need to set the keyboard model to evdev

setxkbmap -model evdev

/usr/bin/setleds -D +num (sets numlock on)

in rc.local:
for vc in /dev/vc/{1..3}; do /usr/bin/setleds -D +num < "$vc"; done

recovering lost partition table with gpart

Today when I switched on my Acer Aspire One (which has Archlinux installed) I was particularly pleased to discover that the SD had no valid partition table.
I was pleased because it was an gift for me to learn something new.
Recovery proved to be extremely simple:
gpart -W /dev/mmcblk0 /dev/mmcblk0

в Linux любой зомби, потерявший родителя, автоматически усыновляется PID=1 (init) и потом через него может быть убит.

MooSE(Work): трогательные строки из документации по внутреннему устройству Linux:
MooSE(Work): "в Linux любой зомби, потерявший родителя, автоматически усыновляется PID=1 (init) и потом через него может быть убит."
MooSE(Work): верх гуманизма: благотворитель init усыновляет осиротевших зомби...

I printed coreutils manual -221pages, and found out that most programs that accept long options recognize unambiguous abbreviations of these options.

for example:
rmdir --ignore-fail-on-none-empty
can be entered simply as rmdir --i
But this is only because there was no other option starting with 'i'. Let us look what would happen if there was. e.g. there are --verbose and --version options. If I enter
rmdir --v
I get
rmdir: option '--v' is ambiguous.

timeout(1)

Sometimes we need to test configuration of some process. And sometimes once we start the process we loose control over the system.
That is the case of Xorg. How can we test configuration?
The problem that I faced was that the keyboard in X did not work.
Solution is simple: timeout seconds command
In the case of xinit (to kill it it after 10sec)it would be:
timeout 10 xinit

Suffixes for time can be used: m, h, d.

Если символ входит в таблицу ANSI, то можно его ввести так:
а) Проверьте — горит ли Num Lock (если нет — включите).
б) Нажмите и удерживайте клавишу Alt.
в) На правой цифровой («телефонной») клавиатуре наберите ANSI-код символа (если он начинается с нуля, то его тоже нужно вводить).
г) Отпустите Alt — это приведёт к вставке нужного символа в текущее текстовое поле.

Вот некоторые из полезных кодов (не забывайте — Alt+Код):

* 0150 – (тире)
* 0151 — (длинное тире)
* 0133 … (многоточие)
* 0171 «
* 0187 »
* 0170 Є
* 0160 (неразрывный пробел)
* 0149 •
* 0176 ° (знак градуса)
* 0169 ©
* 0174 ®
* 0177 ±
* 0167 §
* 0134 †
* 0135 ‡
* 0136 €
* 0137 ‹
* 0155 ›
* 0153 ™ (торговая марка)

27:00 I hate to rehash the whole microkernel thing but how do you feel about it now? Do you think it could ever go in that way?
Ah, microkernels. I used to be a lot more more polite about microkernels now that I used to be in these days. I used to think that microkernels had kind of inherent beauty. I think that's what confused a lot of people. A lot of people thought that microkernels were cute and beautiful. And my current thinking on microkernels is that Linux is actually a microkernel. It does everything that should sanely be done in kernel space, and everything that shouldn't seem to be done in kernel space it does in user level service. Well, that's one level of microkernel. The problem of going much further than that is that yes, you simplify the pieces, but what you don't do is that you do not simplify the system. Quite the reverse. What happens in the microkernel is because you simplify the pieces you now have a lot of interaction between pieces. And there fundamentally have to be asynchronous interaction between pieces if you want to get any good performance at all. Which means that you have asynchronous communication between hundreds of different pieces and you've just made your life living hell. Which is fundamental problem of microkernels that the reason for their existence systems, namely simplicity, isn't actually true. And then you also find that when you add a lot of communication you slow down the problem space... to counteract that you actually make the pieces complicated again in order to get back the performance you lost. Now this is why I think for example that all the traditional microkernels like this are stupid.
This doesn't necessarily mean that distributed systems are stupid. There's two things here and sometimes people seem to be equating microkernels with distributed systems. It's perfectly sane to have a real kernel on lots of machines and then take communication where you have to take communication between the machines. And there you can't avoid it. Well, you can avoid it by having SMP and NUMA. And actually you should take SMP and NUMA as far as you can, but at some point you just can't go any further. And whet you have you take communication, then you do it until you reach some point. But you communicate as soon as possible until that point. That's my strong opinion and I think that computer science as it came to operating system did most of what should've been done in the sixties. And everything else was mental masturbation

42:40 Fragmentation drives development. Because those different people with different agendas.
46:20 It doesn't actually matter what you do. If you are doing it with a good group of people it's gonna be good.
47:00 How do you decide what to include in the kernel? - who's a good maintainer. That's probably the most common reason.
48:50 I am completely disorganized. I'm actually the least organized person I know. Despite that there has to be this invisible guiding hand. ...
55:00 What editor and mail program do you use? The editor is microemacs, the best editor ever made. And vi and GNU Emacs suck, suck. Now I've alienated everybody in the audience. For e-mail I actuall use pine.
56:00 I hate maintaining the stable kernel.

Very first webcasts

постоянное совершенствование

IA> Если админ не знает, что нужно улучшыть -- то это плохой админ.
AN> То есть хэппи энд не предвидится? Всю жизнь до глубокой пенсии улучшай да улучшай и не минутки пива отвыпить?
VW> Это как игра в тетрис. Выиграть нельзя, можно только продержаться подольше.
VW> Потому что тетрис - это замечательная модель борьбы с хаосом, каковым системное администрирование и является.

требования ОС к железу

Для работы Windows 3.х достаточно процессора с тактовой частотой менее 10 мегагерц, 640 килобайт оперативной памяти и семь мегабайт на жестком диске. Также для Windows 3.х необходима видеокарта, поддерживающая стандарты CGA, EGA и VGA.

W3C standards are written with technical completeness in mind rather than education

ease of use

If every programmer had to be concerned with how disk drives work, and with all the dozens of things that can go wrong when reaing a disk block, it is unlikely that many programs could be written at all.
Andrew S.Tanenbaum

when is the next Friday Ocober 25?

y=2005; while [ $y -le 2020 ];do cal -m october $y;y=$(($y+1));done|grep '21 22 23 24 25 26 27' -B5

Тестирование может найти несоответствие, но не может гарантировать правильность

paste

ls -a |paste - - - -

emacs

.."always keep on principle in mind: Emacs does many things well, but it isn't important for that reason. Emacs is important because of the integration of different things you need to do.

(Learning GNU Emacs, Third edition by Debra Cameron, James Elliott, Marc Loy, Eric Raymond, and Bill Rosenblatt @2005 O'Reilly Media, Inc.)

solaris printing

lpadmin -o protocol={bsd|tcp} -o dest=printer:queue-or-port -m netstandard{_foomatic}

solaris smc

/usr/sadm/bin/smc&
RBAC a role has its login, mailbox (all role members get it)