Terminal

Question 1

How to see how much storage is left in a current directory?

Answer 1

df -h .

> > > Filesystem Size Used Avail Use% Mounted on
/dev/nvme0n1p5 458G 362G 73G 84% /

Question 2

How to see how much storage has current directory is using

Answer 2

du -sh .
»»>821M .

Question 3

How to generate ssh keys

Answer 3

ssh-keygen

Question 4

How to setup passless authentication

Answer 4

$ ssh-keygen
# for <username>@<host>
$ ssh-copy-id example@niagara.scinet.utoronto.ca

Question 5

What is the basic command to view all your jobs on Compute Canada?

Answer 5

squeue -u $USER

Question 6

How do you cancel ALL your jobs at once?

Answer 6

scancel -u $USER

Question 7

What command shows detailed information about a specific job?

Answer 7

scontrol show job <jobid></jobid>

Question 8

How do you view only your RUNNING jobs?

Answer 8

squeue -u $USER -t RUNNING

Question 9

How do you cancel only PENDING jobs?

Answer 9

scancel -t PENDING -u $USERx

Question 10

How do you permanently set an environment variable for a single user?

Answer 10

Add ‘export VARIABLE_NAME=value’ to ~/.bashrc file.

Question 11

What is the difference between a shell variable and an environment variable?

Answer 11

Shell variables are only available in current shell, while environment variables are available to current shell and all child processes.

Question 12

What command shows all current environment variables in Linux?

Answer 12

The ‘printenv’ command displays all environment variables.

Question 13

How do you add a new directory to the PATH variable?

Answer 13

Use ‘export PATH=$PATH:/new/directory’ to append a new directory to PATH.

Question 14

How do you remove/unset an environment variable?

Answer 14

Use the ‘unset VARIABLE_NAME’ command.