Datasheet

ln [option(s)] source target Creates an internal link from source to
target. Normally, such a link points directly to source on the same file
system. However, if ln is executed with the -s option, it creates a symbolic
link that only points to the directory in which source is located, enabling
linking across file systems.
-s Creates a symbolic link
cd [options(s)] [directory] Changes the current directory. cd without
any parameters changes to the user’s home directory.
mkdir [option(s)] directoryname
Creates a new directory.
rmdir [option(s)] directoryname
Deletes the specified directory, if it is already empty.
chown [option(s)] username[:[group]] file(s)
Transfers ownership of a file to the user with the specified username.
-R Changes files and directories in all subdirectories
chgrp [option(s)] groupname file(s)
Transfers the group ownership of a given file to the group with the spec-
ified group name. The file owner can only change group ownership if a
member of both the current and the new group.
chmod [options] mode file(s) Changes the access permissions.
The mode parameter has three parts: group, access, and access type.
group accepts the following characters:
u user
g group
o others
For access, grant access with + and deny it with -.
The access type is controlled by the following options:
r read
w write
x execute—executing files or changing to the directory
262 19.3. Important Linux Commands