SAGARFIVE

Linux User File Permissions

Filetype + users permission Index

/

links

owner user size date time File name
rw-rw-r– 1 opc opc Sep  5 02:31 file2

 

File Types ( first letter )
  • : file
d : directory l: link
File Permissions r → read (r) w → write (w) e → execute (x)
rw- rw- r– ( – means no permission) first three for owner/admin (a) next : group (g) last : others (o)

 

1 Add – Owner(a) + execution(x) to file chmod a+x <filename>
2 Add  – group(g) + execution(x) to file chmod g+x <filename>
3 Add  – others(o) + execution(x) to file chmod o+x <filename>
4 Add owner,group,other + exe(x) to file chmod o+x,g+x,o+x <filename>
5 Add all permission to all chmod o+rwx,g+rwx,o+rwx <filename>

 

File Permissions r → read (4) w → write (2) e → execute (1)
rw- rw- r–(-means no permission) rw- →owner : r+w+e=4+2+0=6 rw- →group : r+w+e=4+2+0=6 r- – →others : r+w+e=4+0+0=4

 

1 Add Permissions a→rwx, g→rw, o→r ⇒ rwxrw-r– chmod 764 <filename>
2 Add Permissions a→rwx, g→rw, o→r ⇒ rwxr–r– chmod 744 <filename>
3 change –xr–r– ⇒ rwxr-xr– chmod 754 <filename>