[TOC]
> #(std) satandar output
2> #(stderr) standar error
sort < list > sorted_list #combined input output
ls 2> error 2>&1
Three types of comands: * Aliases * excecuted before anything else * internal Commands * Is part of the sheel itself, doe snot have to be loaded from te disk, * External Commands * is a command that existe on the disk as a separate file.
type command can be used to know what type of command it is
which coomand can be use to find out which command the sheel will be using
vimtutor is ca coomand which helps you lest vim
Vim basic:
| command | explanation |
|---|---|
| esc | enter command mode |
| i | 'insert' behind the carrot |
| a | 'append' after the carrot |
| o | edit in new line below carrot |
| O | edit in line above carrot |
| :w | 'write' do disk |
| q | 'quit' |
| :w filename | 'write' document into filename |
| dd | 'delete' line |
| yy | 'yank' line |
| v | enter 'visual' mode |
| u | 'undo' |
| Crtl-r | 'redo' |
| gg | gos to first line in doc |
| G | goes to last line in do |
| /text | searches for text in doc |
| ?text | searches for text backward in doc |
| ^ | frist posicion in current line |
| $ | last posicion in current line |
| !ls | adds the outlut of ls, into the file |
| :%s/old/new/g | 'subtitudes' old with new in whole file' |
system width configs
/etc/ssh/ssh_config
user file, overrides system configs
~/.ssh/config
Generates a public and privates keys
ssh-keygen
saves to
~/.ssh/id_rsa
~/.ssh/id_rsa.pub
Copies your public id over th te target
ssh-copy-id
I think it sends a single window trough the ssh connection
ssh -X user@server
| Old | Replaced by |
|---|---|
| Telnet | ssh |
| rcp (remote copy) | scp (secure copy) |
| ftp (file tranfer protocol) | sftp ( secure file tranfer protocol) |
suptitude user
su
Set up the enviroment when
su - lucy
Run a single command as an other user
su -C "fdisk -l"
Means that the shell is run wit the interaction of the usr, suh as opening the terminal, as opposued to the non-interactive shell.
.bashrc runs when in interactive
Runs as part to the user loggin into the system as opposued to a non-login which can be automated process
.bash_profile
Commands run when log out
- .bash_logout
Command history
- .bash_history
- search hisory
crl-r
tar cvf home.tar /home
- create a tar archive
- verbose
- filename
tar xvf home.tar /home
- extracts a tar archive
- Verbose
- filename
-z or -j compresses behaivor
gzip bigfile.stuff
gzip -d bigfile.stuff.gz
bzip2 bigfile.stuff
bzip2 -d bigfile.stuff.bz2
zip -r zippedFileName.zip /home
unzip zippedFileName.zp
A File:
A Pointer to a 'inode' which live on the disk
ls -i file.stuff
Commands:
- find
- locate
locate https.config - cat
- less
- more
- head
- less
- sort
-rrevese - wc
-lline count - diff
- patch
Point to the same inode to the disk
is a pointer to the filenames of other files
type of file:
- => regualr files
d => directory
UEFI/BIOS -> GRUP2
Grub
ls -> disks cat rd.break emergency rescue
top
ps
acceps difrent rypes od opstions: UNIX: which may be a be a groupd and must be preceded by a dash ( -aux ) GNU: which my be grouped and must not be used with a dash ( aux ) BSD: long options wch are receded by two dashes ( --group ) a all process u display usr format x all Proceses
pgrep [options] pattern
compbines the grep and ps to give relevant infomation -l process nams -u Limited the matches to user -v incerse result
Kill Signals
kill [options] pattern compbines the grep and ps to give relevant infomation -l list kill signals 15 SIGTERM Ask the process to end politely 9 SIGKILL Stops thhe process imidetly (leave file open...) 9 SIGHUP Stops tthe process in the shell eviroment, the binary must be have the configuration to be able to to interact with it 2 SIGINT ( crl-c ) 19 SIGSTOP Tells a preocess to stop, similar to how the crtl-z 18 SIGCONT Tells a proccess to continue 20 SIGTSTP (Terminal Stop) relies on the binary on knowing how to process the signal
The more priority a process has the less nice it is, and vv
High priority, not nice [-20, 19] nice, low propieirty The lower the level the highest the priority, the less nice it is renice 0 just share the CPU
Average of teads or processes waiting for a resorces over a period of time 1, 5, 15 minustes
load average over the last 1 minute: 1.05 load average over the last 5 minutes: 0.70 load average over the last 15 minutes: 5.09
over the last 1 minute: The computer was overloaded by 5% on average. On average, .05 processes were waiting for the CPU. (1.05) over the last 5 minutes: The CPU idled for 30% of the time. (0.70) over the last 15 minutes: The computer was overloaded by 409% on average. On average, 4.09 processes were waiting for the CPU. (5.09)
/dev/null produces no output.
/dev/zero produces a continuous stream of NULL (zero value) bytes.
come back to it
come back to it