COMMANDS:
bash -x ifdown eth0 --> debug mode for bash
UID --> user identification, GID --> group identification
(these r equal to username and group name from prompt)
shutdown -h now (put in /etc/shutdown.allow list of users )
-n 13:20 --> shutdown the system at this time!.
init 6 --> reboot
0 --> shutdown
halt, poweroff,logout,exit,ctrl+d
sleep 20;ls --> rest 20 sec than ls
strace mail (command_name) --> tasks that command did
useradd user_name-->add user
userdel -r user_name-->remove user+home dir
(or from /etc/passwd, shadow ,group)
passwd user_name -->add passward
-l --> lock user (u unlock, -d disable)
soft link: ln -s /D1/D2/D3 /users/david/file1 (up 2 255 char)
hard link: ln /home/file1 /root/file2
(cannot b done on directories)
ls -la file2 --> statistic if orginal file
-i|more --> in clumns & page by page
-R --> with color
when there is an S in the charecters: program
would not run under UID but under root.
set GID -->will run under group permissions
when u open file in a dir than u get the group of the dir
echo $HOME -->home dir
$((RANDOM)) --> gives a 5 numbers random number
$((15/5)) work as a calculator (gives 3)
users -->who is connected
clear -->clear screen
history 13 --> give us 13 last commands
!22 ->to make command history
echo shalom --> writes shalom
echo oren >> f2 -->puts oren into end of file f2
(append)
date;netscape;date -->show axact time & date
after closing netscape, date
date > list.txt --> go over him
date >|list.txt -->temporarily get output inside
cal --->calender cal 01--->all year
bc <-->ctrl+D --->calculator
w -->show all useres
who am i
who -H-->with explanation
-q-->number of users
man -k vnc --> look for the word all over the first line
ls -l ,-i,-a(hidden),-s(by size): ls -R /tmp
-->recursive (all inside)
ls -1 -->in clumn, -ld -->all in dir,ls -i
-->i node,-F -->executable
ls file1 file2 >out.txt 2>err.txt
-->output to out.txt errors to err.txt
ls file1 ffff > out.txt 2>&1
-->send all output to out.txt
ls > k --> enter input into k
set -o noclobber -->after saving to file output
wont get inside exsisting file
set +o noclobber --> cancel first command
/user/sbin/makewhatis -->to built index:
man -k cdrom:man -k mount
mkdir tt,dir2 dir3 --> 3 new directories
-p /home/ron/avi/dir1 --> make dirs even
if they dont exsist
-p {1,2,3}/file_{A,B,C}_{1,2,3}
--> will give u 3 dirs with 9 files in it
cd --> cd\ ;cd .. --> 1 dir up;cd -->to home dir;
cp file1 file8 -->copy cp -R hhh HHH hhH
-->all inside hhh+HHH to hhH
-i --> with question (interactive)
-R /tmp . -->copy all in /tmp to current dir
-p --> with time & permissions
*.txt dir1 ; cp sect?b part1
-->sect[1-9]b to dir part1
docs/vi.z /tmp --> copy vi.z in dir docs to /tmp
mv pro_1 pro_2 -->move or rename
-i file1 /tmp --> with question;mv ~ -->to home dir
rmdir dir_name --> remove directory
rm -i file_name -->delete files with question
-r dir1 (also R)--> all what inside
the dir- recursively
-f "*.pbm" --> with no questions and only
the file *.pmb(not all files with
this extention!)
errors:
-never do: rm -rf ??* in a dir before u know what is ??* !!!
-when u c: sh: /bin/rm: Argument list too long: use this:
find . -name "mgetty*" -print | xargs rm
finger -lmsp lilach --> gives u the last login
and mails of the user
who;finger;pwd --->; all in 1 line
| | ---> also pipe shows last output
&& --> just when first 1 made
|| --> 1 command is made but the other not
runlevel --> at which level r we (N 3 = 3 level)
init level_number -->to go to each level ; init 5
sulogin --> log in as root
su user_name --> make switch to other user
- user_name --> make total switch to other
user(home dir, profile)
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