Linux referance

1.#pwd

2.#ls (files and sub dir)

3.#ls -l

4.#chmod 765 abc.txt  (r-4,w-2,x-1)

5.#chmod -r 765 /home/oracle/xyz

6.#chown antony:msc abc.txt   (antony-owner,msc-group)

7.#chown -r antony:msc /home/oracle/xyz

8.#ls -al

9.#ls -lt

10.#ls -ltr

11.#ls -lf

12.#ls -lb (display size in byts)

13.#cat>abc.txt (ctrl+d -save)

14.#more abc.txt

15.#rm -fr * (remove for the particular mount point)

16.#head -10 abc.txt

17.#cat abc.txt|tail -10

18.#head -7 abc.txt|tail -3

19.#ls -l|grep "sep"

20.#cat abc.txt|grep "mani"

21.#ls -l |egrep "(sep|nov)"

22.#ls -l |grep -v "oct"   (-v same for <>)

23.#touch xyz.txt

24.#cp abc.txt xyz.txt

25.#cp * /backup

26.#cp -r * /backup   (files and subdirectory)

27.#mv abc.txt /backup

28.#mkdir app

29.#mkdir -p /opt/oracle/..

30.#mkdir d1 d2 d3

31.#mount /dev/cdrom /mnt

32.#cd /mnt

33.#cd /  #eject  (remove disk)

34.#kill -9(or)q <pid>

35.#df -h

36.#df -m

37.#du -h oracle

38.#ps -ef

39.#ps -ef |grep pmon|wc

40.#more /etc/oratab

41.#cat /etc/oratab

42.#free -m

44.#find . -name "*.arc" -print

45.#gzip *.arc

46.#gunzip *.gz

47.#rm -fr *.arc

48.#crontab -e

49.#crontab -l

50.#crontab -r