Kratek povzetek snovi za prostopni kolokvij (A short summary of the material for the entrance exam)

 
COMMANDS:
man - manual pages
less, more - paginate output
cd - Change Directory
pwd - show current directory
ls - list directory content
cat - output file to stdout (screen)
echo - output argument to stdout
env - output environment
ps - list proceses
grep - filter text
ifconfig - show network interfaces
route - show routes
arp - show the Address Resolution Protocol table
sleep - block for N seconds
kill - kill process
killall - kill processes with a certain name
top - display a list of processes
source - interpret the commands inside a file
export - set an environment variable
chown - change owner
chmod - change permissions
which - which program would be run
head - output the first few lines of a file
tail - output the last few lines of a file
wc - word count
bg - run the stopped program in the background
fg - get the program from the background to the foreground
mount - attach a filesystem to the current directory structure

DIRECTORIES:

cd /SOME_PATH # move to /SOME_PATH
cd SOME_PATH # move to $PWD/SOME_PATH
./ # current directory
.some_name # a file called .some_name which is hidden
../ # 1 level "up" (parent directory)
~ # $HOME
~/ # $HOME/
~some_name # the home dir of some_name
file~ # a file called file~
f~i~l~e # a file called f~i~l~e
~- # $OLDPWD

ENVIRONMENT:

PWD # current directory
OLDPWD # PWD before the last successfull cd
PATH # a ":" separated list of directories of programs
(DOES NOT CONTAIN THE CURRENT DIRECTORY by default)
DISPLAY

SYMBOLS:
>
prog1 > file1 # redirect stdout from prog1 into file1
>> #
prog1 >> file1 # append stdout prog1 to file1
<
prog1 < file1 # redirect file1 to stdin of prog1
|
prog1 | prog2 # redirect stdout of prog1 to stdin of prog2
A>&B
prog1 2> file1 # redirect stderr of prog1 to file1
prog1 >&2 # redirect stdout of prog1 to stderr
prog1 2>&1 # redirect stderr of prog1 to stdout
prog1 2>&1 | less

&
prog1 & prog2 # |---prog1---| &
|-----prog2------|
&&
prog1 && prog2 # run prog2 after prog1 terminated successfully
;
prog1; prog2 # run prog2 after prog1 (ignore the return code)
{
}
{ prog1; prog2; } # run prog1 and prog2 in a sub-shell

$
echo $PATH # echo the_value_in_PATH
echo $PWD$PATH # echo the curr. dir + the path

`
`prog1` -> get the output of prog1 into a string
export WHERE_I_AM=`pwd`
export CURRENT_DATE=`date`

"
"string with escape sequences"
'
'normal(raw) strings'

. # source
. file # same as source file

CTRL+C - break (program)
CTRL+Z - stop the current program, put it into the background
CTRL+D - end of file
CTRL+R - search history

IPs:
Local networks:
192.168.0.0/16, (192.168.0.0 - 192.168.255.255)
172.16.0.0/12, (172.16.0.0 - 172.31.255.255)
10.0.0.0/8, (10.0.0.0 - 10.255.255.255)
Other special networks:
127.0.0.0/8 - localnet
169.254.0.0/16 - link-local addresses
Zadnja sprememba: torek, 24. oktober 2017, 11:21