ADV *NIX DAY 4 Flashcards
A variable and its value are displayed using echo $variable.
echo
Displays existing shell variables, environmental variables and shell functions.
set
Make a shell variable available with newly forked child processes, for that session only.
export
Display existing environmental variables.
env
Read and execute commands from filename in the current shell environment.
source
Run a shell with substitute user and group IDs.
su
OpenSSH, an SSH client for logging and executing commands on a remote machine. Provides secure encrypted communications between two untrusted hosts over an insecure network.
ssh
Secure copy (remote file copy program)uses SSH for data transfer. Also uses the same authentication and provides the same security as SSH.
scp
Secure file transfer program. An interactive file transfer program, similar to FTP, which performs all operations over an encrypted SSH transport.
sftp
Change your login shell or list available shells on the system.
chsh
Create a new group account using specified values and default system values.
groupadd
Change the current group ID during a login session.
newgrp
Create a new user or update default new user information.
useradd
Update authentication tokens (aging info), to include changing password for a user.
passwd
Change or list user password expiry information.
chage
Modify an existing user account.
usermod
Delete a user.
userdel –rf Deletes a user, their home directory and its contents.
userdel
Password sync utility. Convert information in /etc/passwd to /etc/shadow.
pwconv
Print real and effective user and group IDs.
id
System wide environment and startup programs.
/etc/profile
User specific environment and startup programs.
~/.bash_profile
User specific aliases and functions.
~/.bashrc
System wide aliases and functions.
/etc/bashrc
Used for authentication and authorization, contains user account information.
/etc/passwd
Used for authentication, contains hashed password and aging information for user accounts.
/etc/shadow
Defines the site-specific configuration for the shadow password suite, encryption method used.
/etc/login.defs
Used for authorization, contains a listing of every group on the system and is where supplemental group membership is maintained.
/etc/group
