Mars Server Reference Sheet for CSCI 316

Mars Connectivity

Account Information

• Server: mars.cs.qc.cuny.edu
• Username Format: xxxxx_yyyy316
  • xxxxx = Last name (lowercase, ≤5 chars) or first 5 letters if longer
  • yyyy = First name (lowercase, ≤4 chars) or first 4 letters if longer
• Initial Password: q + last 7 digits of CUNYfirst ID
• Required: Change password on first login

Connection Requirements

• From Off-Campus: QC VPN (GlobalProtect) must be connected
• From On-Campus: Connect to qwifi-secured wireless network
• Note: Must set up CUNY login MFA before installing GlobalProtect VPN client

Initial Setup

1. ssh xxxxx_yyyy316@mars.cs.qc.cuny.edu
2. (Enter initial password)
3. passwd (Change your password)
4. (Log off and log back in with new password)
5. source /home/faculty/ykong/316setup (Get 0.25 pt extra credit if by Sept 11)
6. cl (Test that Clisp works)

Once logged in, run:

source /home/faculty/ykong/316setup

Benefits: Enables cl command (Clisp) and kawa command (Scheme); qualifies for 0.25 pt extra credit if completed by Thursday, September 11.

Quick Reference: Key Commands

Task	Command	Location	Notes
Connect to Mars	ssh xxxxx_yyyy316@mars.cs.qc.cuny.edu	Local: PowerShell/Terminal	First time: type yes to continue
Fix host key issue	ssh-keygen -R mars.cs.qc.cuny.edu	Local: PowerShell/Terminal	Run if “REMOTE HOST IDENTIFICATION HAS CHANGED”
Start Clisp	cl	Remote: Mars prompt	After running 316setup
Start Kawa Scheme	kawa	Remote: Mars prompt	For Scheme solutions; requires 316setup
Copy file to Mars	scp local_file.ext xxxxx_yyyy316@mars.cs.qc.cuny.edu:destination/:	Local: PowerShell/Terminal	Requires QC VPN or qwifi network
Copy file from Mars	scp xxxxx_yyyy316@mars.cs.qc.cuny.edu:remotefile.ext .	Local: PowerShell/Terminal	Requires QC VPN or qwifi network
Change password	passwd	Remote: Mars prompt	Run after first login

Lisp Assignment Submission

Submission Process

1. Place solution file in home directory on mars: your-last-name-N.lsp (where N = assignment number)
2. At the xxxxx_yyyy316@mars:~$ prompt, enter:

submit_lisp_asn your-last-name N

Example: To submit Assignment 5, if your name is David Touretzky:

submit_lisp_asn touretzky 5

Check submitted assignment — Run on mars:

ckasn

At resulting Lisp > prompt:

(quickcheck 'last_name assignment_number)

Example:

(quickcheck 'touretzky 5)

TinyJ Assignment Submission

TinyJ Assignment 1 (Parser)

submit_TJ_asn1

File location: TJ1asn/Parser.java (home directory on mars)

TinyJ Assignment 2 (ParserAndTranslator)

submit_TJ_asn2

File location: TJasn/ParserAndTranslator.java (home directory on mars)

TinyJ Assignment 3 (Virtual Machine)

submit_TJ_asn3

File location: TJasn/virtualMachine (home directory on mars)

Checking Submission Status and Late Submissions

Check If Files Were Submitted

Run these commands at the xxxxx_yyyy316@mars:~$ prompt to check submission timestamps (ctimes):

ls -lLc submitted-Lisp-assignments                              # Lisp Assignments 2–5
ls -lLc submitted-TinyJ-assignments/TJ1asn/Parser.java         # TinyJ Assignment 1
ls -lLc submitted-TinyJ-assignments/TJasn/ParserAndTranslator.java  # TinyJ Assignment 2
ls -lLc submitted-TinyJ-assignments/TJasn/virtualMachine        # TinyJ Assignment 3

Interpretation:

• “total 0” or “No such file or directory” = No submission found
• ctime after due date = Late submission
• ctime before due date = On-time submission

Late Submission Deadline

• General deadline: Noon on Wednesday, December 24, 2025
• Condition: Mars must be operating normally and accessible
• Important: If mars becomes inaccessible after 6 p.m. on the assignment’s due date, the deadline will NOT be extended

Text Editors on Mars

• nano: Easy for beginners
• vim: Powerful but steep learning curve
• emacs: Full-featured editor
• less: View-only file viewer

Available Resources on Mars

Command	Purpose	Location	Example
ls -l	List files with details	Remote: Mars	ls -l TJ1asn/
cd	Change directory	Remote: Mars	cd TJ1asn
pwd	Print working directory	Remote: Mars	pwd
cat	View file contents	Remote: Mars	cat CS316ex0.java
less	Page through file	Remote: Mars	less Parser.java.txt
diff -c	Compare files	Remote: Mars	diff -c 0.sol 0.out
javac	Compile Java	Remote: Mars	javac TJ1asn/Parser.java
java	Run Java	Remote: Mars	java TJasn.TJ ...
cl	Start Clisp	Remote: Mars	cl
kawa	Start Scheme	Remote: Mars	kawa

Important Policies

Mars Downtime Policy

• If mars becomes inaccessible after 6 p.m. on the due date, the deadline will NOT be extended
• Late submissions accepted only if mars is operational
• Recommendation: Submit well before 6 p.m. on the due date, ideally by noon

Submission Requirements

• Files must be in correct location on mars
• Java code must compile without errors on mars
• Late submission penalty: -1 point per late submission if 4+ assignments are submitted late
• Submit early to avoid issues with mars availability

Copying Files

• Do not rely on copying files from PC/Mac as an excuse for late submission
• Test copying files from your PC/MAC to mars ahead of time before relying on it for assignment submission
• Problems with file copying will not be considered legitimate reasons for late submission

Common Setup Sequences

TinyJ Assignment 1 Setup

1. SSH to mars
2. /home/faculty/ykong/TJ1setup (At mars prompt)
3. ls -l TJ1asn/ (Verify files exist)
4. Check assignment document for specific Parser.java placeholder locations

TinyJ Assignment 2 Setup

1. SSH to mars
2. /home/faculty/ykong/TJ2setup
3. Download TJasn.jar via scp to local machine

TinyJ Assignment 3 Setup

1. SSH to mars
2. /home/faculty/ykong/TJ3setup
3. Implement virtual machine instruction classes

Lisp-Specific Commands

Task	Command	Location
Start Clisp	cl	Remote: Mars prompt
Load file	(load "filename")	Remote: Clisp > prompt
Test solution	(quickcheck 'last_name N)	Remote: Clisp > prompt (after ckasn)
Exit Clisp	(quit) or Ctrl+D	Remote: Clisp > prompt
View SDRAW	(sdraw expression)	Remote: Clisp > prompt

Troubleshooting

Issue	Solution
Cannot connect to mars	Verify QC VPN is connected or on qwifi network
”REMOTE HOST IDENTIFICATION HAS CHANGED”	Run ssh-keygen -R mars.cs.qc.cuny.edu
command not found for cl or kawa	Run source /home/faculty/ykong/316setup
File copy fails	Ensure QC VPN is connected; try SFTP client as alternative
Compilation fails on mars	Check working directory is home (~) for TinyJ; check class paths
Clisp gives “Break …>” prompt	Syntax error in code. Fix with ctrl+D
ls -lLc submitted-* shows “total 0”	File not found in expected location; verify submission command