tips.md

Find and Locate

Both are used to find the location of the file . find commmand returns the relative path whereas locate returns the absolute path

Note

If locate command is not found or it is not found then run following commands

1. rpm -qa | grep mlocate
2. yum install mlocate
3. locate test.sh
4. updatedb
5. locate test.sh

Soft link and Hard link

1. ln for create hard link ( Hardlink works with in same partition)
2. Hard links are only for files
3. Deleting the source file will not impact the hardlink.
4. Soft links can be for files and directories
5. ln -s create soft link (ln -s source dest)
6. ls -i returns the node number

File permission

1. x permission allow a directory to go inside if a directory does not have the x permission then we cannot go inside it.
2. chmod a+x where a indicates everyone.
3. 6- rw 5 wx 3 xw 2 w 1 x
4. getfacl test will return

To Add the permission to a user

setfacl -m u:user:rwx /path setfacl -m u:raman:rwx /tmp/test

To Add the permission to a group

setfacl -m g:group:rw /path setfacl -m g:ec2-user /tmp/dir

To allow all the files or directories to inherit ACL entries from the directory it is within

TBS

To remove the permission for a specific user

setfacl -x u:raman test

To remove all the entries

setfacl -b test Note -w option not allow to delete the directory/file but you can modify

Help Commandsh

1. whatis it gives very minimal information like whatis touch
2. help it gives gives descriptive information of a command ls --help
3. man it gives more descriptive command