CS 3343/3341: Accessing UTSA from Linux or Mac OS X

CS 3343/3341
Analysis of Algorithms
Fall 2012

Accessing UTSA from
Linux or Mac OS X

Submissions from Remote Linux: I never explained how a person working entirely at home in Linux could submit recitations. This is the old-fashioned way that I use to work from home. Exactly the same stuff works for Apple's Mac OS X. Below is an interactive session illustrating access to a CS elk machine from my Linux. Here a (non-existent) student named "Ned Wagner" wants to submit a file "rec1.txt" from the student account "nwagner". He has this file already prepared on his computer at home. He needs to get this file into the CS system. I will show two strategies:

Copy-paste the file into an editor (say vi at UTSA). I don't recommend this.
Use sftp, the secure file transfer, to transfer the file to UTSA.

Interactive Session Using Secure Shell and an Editor: The purple text is what Ned Wagner types in. The orange text are comments, not typed in, and not appearing at all in the session.

neal@linux-d8ag:~> date # date command Sat Jan 28 08:30:54 CST 2012 neal@linux-d8ag:~> ssh nwagner@elk05.cs.utsa.edu # secure shell to elk05 nwagner@elk05.cs.utsa.edu's password: # crap! used my other password Permission denied, please try again. nwagner@elk05.cs.utsa.edu's password: # OK, this worked # the system may demand that you respond "yes" to a question about security elk05:~> pwd # show current directory /home/nwagner elk05:~> ls # list contents CS3343 mbox public_html working elk05:~> cd public_html # change directories elk05:~/public_html> ls # list contents index.htm elk05:~/public_html> mkdir rec1 # make a new directory elk05:~/public_html> cd rec1 # change to this new directory elk05:~/public_html/rec1> vi rec1.txt # create a new file at UTSA # first "i" is for "insert". Then I pasted in my prepared rec1.txt file iIn all men's lives at certain periods, a dominate element is the desire to be inside the local Ring and terror of being left outside. Of all the passions the passion for the Inner Ring is most skilful in making a man who is not yet a very bad man do very bad things. -- C.S. Lewis, "The Inner Ring" (1944) [Esc] ZZ # ZZ command saves file and quits vi elk05:~/public_html/rec1> ls # Yep, file is there rec1.txt elk05:~/public_html/rec1> ~wagner/bin/cs3343r1 < rec1.txt # submit for rec 1 CS 3343, Analysis of Algorithms, Spring 2012 Processing Recitation Number 1 Submission Date/Time: Sat Jan 28 08:13:06 2012 Full Credit Date/Time: Mon Jan 23 23:59:59 2012 Part Credit Date/Time: Fri Jan 27 23:59:59 2012 Received and archived, but for NO CREDIT 309 bytes and 6 lines received. The received file has been emailed to you for confirmation. elk05:~/public_html/rec1> mailx # check mail Heirloom mailx version 12.4pre 6/29/08. Type ? for help. "/var/mail/nwagner": 7 messages 2 new 6 unread N 7 Ned Wagner St Sat Jan 28 08:13 36/1554 ? 7 Message 7: From nwagner@cs.utsa.edu Sat Jan 28 08:13:07 2012 # lines omitted Submitted by: nwagner@cs.utsa.edu Course: CS 3343, Spring 2012, Recitation 1 Time Received: Sat Jan 28 08:13:06 2012 Credit: NONE In all men's lives at certain periods, a dominate element is the desire to be inside the local Ring and terror of being left outside. Of all the passions the passion for the Inner Ring is most skilful in making a man who is not yet a very bad man do very bad things. -- C.S. Lewis, "The Inner Ring" (1944) ? exit elk05:~/public_html/rec1> logout Connection to elk05.cs.utsa.edu closed. neal@linux-d8ag:~> # there's no place like home

neal@linux-d8ag:~> date  # date command
Sat Jan 28 08:30:54 CST 2012
neal@linux-d8ag:~> ssh nwagner@elk05.cs.utsa.edu # secure shell to elk05
nwagner@elk05.cs.utsa.edu's password: # crap! used my other password
Permission denied, please try again.
nwagner@elk05.cs.utsa.edu's password: # OK, this worked
# the system may demand that you respond "yes" to a question about security
elk05:~> pwd             # show current directory
/home/nwagner
elk05:~> ls              # list contents
CS3343  mbox  public_html  working
elk05:~> cd public_html  # change directories
elk05:~/public_html> ls  # list contents
index.htm
elk05:~/public_html> mkdir rec1   # make a new directory
elk05:~/public_html> cd rec1   # change to this new directory
elk05:~/public_html/rec1> vi rec1.txt   # create a new file at UTSA
# first "i" is for "insert".  Then I pasted in my prepared rec1.txt file
iIn all men's lives at certain periods, a dominate element is the desire
to be inside the local Ring and terror of being left outside.  Of all the
passions the passion for the Inner Ring is most skilful in making a man
who is not yet a very bad man do very bad things.
-- C.S. Lewis, "The Inner Ring" (1944)
[Esc] ZZ   # ZZ command saves file and quits vi
elk05:~/public_html/rec1> ls   # Yep, file is there
rec1.txt
elk05:~/public_html/rec1> ~wagner/bin/cs3343r1 < rec1.txt # submit for rec 1
CS 3343, Analysis of Algorithms, Spring 2012
Processing Recitation Number 1
Submission  Date/Time: Sat Jan 28 08:13:06 2012
Full Credit Date/Time: Mon Jan 23 23:59:59 2012
Part Credit Date/Time: Fri Jan 27 23:59:59 2012
Received and archived, but for NO CREDIT
309 bytes and 6 lines received.
The received file has been emailed to you for confirmation.
elk05:~/public_html/rec1> mailx  # check mail
Heirloom mailx version 12.4pre 6/29/08.  Type ? for help.
"/var/mail/nwagner": 7 messages 2 new 6 unread
 N  7 Ned Wagner St Sat Jan 28 08:13   36/1554  
? 7
Message  7:
From nwagner@cs.utsa.edu  Sat Jan 28 08:13:07 2012
# lines omitted

Submitted by: nwagner@cs.utsa.edu
Course: CS 3343, Spring 2012, Recitation 1
Time Received: Sat Jan 28 08:13:06 2012
Credit: NONE

In all men's lives at certain periods, a dominate element is the desire
to be inside the local Ring and terror of being left outside.  Of all the
passions the passion for the Inner Ring is most skilful in making a man
who is not yet a very bad man do very bad things.
-- C.S. Lewis, "The Inner Ring" (1944)
? exit
elk05:~/public_html/rec1> logout
Connection to elk05.cs.utsa.edu closed.
neal@linux-d8ag:~>   # there's no place like home

Interactive Session Using Secure File Transfer: Here I show how to use sftp to transfer files from a remote Linux to an elk machine. This assumes you have a rec1.txt file at home that you want to submit. You need to get the file into the CS network.

neal@linux-d8ag:~> pwd # which directory am I in /home/neal # linux, at home directory neal@linux-d8ag:~> cd public_html # move locally on to public_html neal@linux-d8ag:~/public_html> cd rec1 # move on to rec1 neal@linux-d8ag:~/public_html/rec1> ls # list files rec1.txt # rec1.txt is already prepared, at home, ready to submit neal@linux-d8ag:~/public_html/rec1> cat rec1.txt # display contents of rec1.txt ... genes that tend to make children cheat have an advantage in the gene pool. If there is a moral to be drawn, it is that we must _teach_ our children altruism, for we cannot expect it from their biological nature. Richard Dawkins, "The Selfish Gene" neal@linux-d8ag:~/public_html/rec1> cd .. # drop out rec1 directory neal@linux-d8ag:~/public_html> neal@linux-d8ag:~/public_html> sftp nwagner@elk06.cs.utsa.edu # initiate secure ftp The authenticity of host 'elk06.cs.utsa.edu (129.115.28.166)' can't be established. RSA key fingerprint is ea:74:d6:0e:02:54:a6:51:53:31:92:60:a9:9f:da:82. Are you sure you want to continue connecting (yes/no)? yes # need first time Warning: Permanently added 'elk06.cs.utsa.edu,129.115.28.166' (RSA) to the list of known hosts. nwagner@elk06.cs.utsa.edu's password: # correct password entered Connected to elk06.cs.utsa.edu. sftp> pwd # what remote directory am I in? Remote working directory: /home/nwagner sftp> lpwd # what local directory am I in? Local working directory: /home/neal/public_html sftp> cd public_html # move on to remote directory public_html sftp> pwd # what remote directory am I in? Remote working directory: /home/nwagner/public_html sftp> cd rec1 # change to remote directory rec1 Couldn't canonicalise: No such file or directory # change fails sftp> lcd rec1 # change to local directory rec1 sftp> ls # list remote files index.htm sftp> lls # list local files rec1.txt # we want to transfer this to the elk sftp> pwd # forgot where I was remotely Remote working directory: /home/nwagner/public_html sftp> lpwd # forgot where I was locally Local working directory: /home/neal/public_html/rec1 sftp> mkdir rec1 # create new directory remotely for submission sftp> cd rec1 # remote change to this new directory sftp> pwd # check again remotely where I am Remote working directory: /home/nwagner/public_html/rec1 sftp> put re1.txt # "put" transfers a file from local to remote stat re1.txt: No such file or directory # crap. file name misspelled sftp> pwd # check again remotely where I am Remote working directory: /home/nwagner/public_html/rec1 sftp> lpwd # check again locally where I am Local working directory: /home/neal/public_html/rec1 sftp> put rec1.txt # this "put" was successful Uploading rec1.txt to /home/nwagner/public_html/rec1/rec1.txt # 252 bytes transferred rec1.txt 100% 252 0.3KB/s 00:00 sftp> quit # quit sftp neal@linux-d8ag:~/public_html> # click heels three times, get back

neal@linux-d8ag:~> pwd                 # which directory am I in
/home/neal                             # linux, at home directory
neal@linux-d8ag:~> cd public_html      # move locally on to public_html
neal@linux-d8ag:~/public_html> cd rec1 # move on to rec1
neal@linux-d8ag:~/public_html/rec1> ls # list files
rec1.txt   # rec1.txt is already prepared, at home, ready to submit
neal@linux-d8ag:~/public_html/rec1> cat rec1.txt   # display contents of rec1.txt
... genes that tend to make children cheat have an advantage
in the gene pool.  If there is a moral to be drawn, it is that
we must _teach_ our children altruism, for we cannot expect
it from their biological nature.
Richard Dawkins, "The Selfish Gene"
neal@linux-d8ag:~/public_html/rec1> cd ..   # drop out rec1 directory
neal@linux-d8ag:~/public_html> 
neal@linux-d8ag:~/public_html> sftp nwagner@elk06.cs.utsa.edu # initiate secure ftp
The authenticity of host 'elk06.cs.utsa.edu (129.115.28.166)' can't be established. 
RSA key fingerprint is ea:74:d6:0e:02:54:a6:51:53:31:92:60:a9:9f:da:82.
Are you sure you want to continue connecting (yes/no)? yes  # need first time
Warning: Permanently added 'elk06.cs.utsa.edu,129.115.28.166'
(RSA) to the list of known hosts.
nwagner@elk06.cs.utsa.edu's password: # correct password entered
Connected to elk06.cs.utsa.edu.
sftp> pwd                             # what remote directory am I in?
Remote working directory: /home/nwagner
sftp> lpwd                            # what local directory am I in?
Local working directory: /home/neal/public_html
sftp> cd public_html                  # move on to remote directory public_html 
sftp> pwd                             # what remote directory am I in?
Remote working directory: /home/nwagner/public_html
sftp> cd rec1                         # change to remote directory rec1
Couldn't canonicalise: No such file or directory   # change fails
sftp> lcd rec1                        # change to local directory rec1
sftp> ls                              # list remote files
index.htm  
sftp> lls                             # list local files
rec1.txt                              # we want to transfer this to the elk
sftp> pwd                             # forgot where I was remotely
Remote working directory: /home/nwagner/public_html
sftp> lpwd                            # forgot where I was locally
Local working directory: /home/neal/public_html/rec1
sftp> mkdir rec1                      # create new directory remotely for submission
sftp> cd rec1                         # remote change to this new directory
sftp> pwd                             # check again remotely where I am
Remote working directory: /home/nwagner/public_html/rec1
sftp> put re1.txt                     # "put" transfers a file from local to remote
stat re1.txt: No such file or directory   # crap.  file name misspelled
sftp> pwd                             # check again remotely where I am
Remote working directory: /home/nwagner/public_html/rec1
sftp> lpwd                            # check again locally where I am
Local working directory: /home/neal/public_html/rec1
sftp> put rec1.txt                    # this "put" was successful
Uploading rec1.txt to /home/nwagner/public_html/rec1/rec1.txt # 252 bytes transferred
rec1.txt                                      100%  252     0.3KB/s   00:00    
sftp> quit                            # quit sftp
neal@linux-d8ag:~/public_html>        # click heels three times, get back

Revision date: 2012-01-28. (Please use ISO 8601, the International Standard.)