UNIX Productivity Hints

• Emacs
• tcsh
• Netscape
• ftp
• retrieving remote groups of files quickly/easily

The following keystrokes are widely available in UNIX programs. All are supported by Emacs; subsets are supported by tcsh, Netscape, MATLAB, IDL, Pine, and GrADS. If you get used to using them things should go much more smoothly. ``C-key'' means Control+key; ``M-key'' means Meta+key or Alt+key (depending on the application). ``Meta'' is the diamond-shaped symbol on Sun keyboards.

Emacs

• You may already use the Emacs' ``major'' modes for HTML, C, and FORTRAN, but there are also modes for MATLAB, IDL, and many other languages. However, these modes are not (yet) included with the Emacs distribution. The MATLAB mode is available here from MathWorks, and IDL mode here. Installation instructions are included.
• Add (column-number-mode t) to your ~/.emacs file. This will force Emacs to display the current column number in the status line in addition to to the line number.
• Add (global-font-lock-mode t) to .emacs to force Emacs to display ``rainbow code.''
• Try show-paren-mode. It is useful for keeping track of which parentheses match which. (i.e. in Emacs press M-x, then type ``show-paren-mode[enter]'')

tcsh

tcsh is an enhanced version of the Berkeley UNIX C shell, csh. Unless you've previously changed your default shell with chsh, you are probably already using it. To determine your shell, use the following:

>echo $SHELL
/bin/tcsh
>

• Try ls-F instead of ls. It will display a ``/'' after directory names, a ``@'' after names of symbolic links, and other characters after other types of files. You may want to add this line to your .cshrc file: alias ls ls-F.
• Add setenv PAGER less to your .cshrc. This will force many UNIX commands (e.g. man) to use less when they would otherwise use more. less is an enhanced version of more.
• Add alias less 'less -i' to your .cshrc. This way searches within less will be case-insensitive.
• Set your shell prompt using set prompt="%m:%U%c03%u>" in your .cshrc. This will display a prompt like tao:~/proj> or tao:/<2>data/mosaic/computer_helps>. The <2> in the latter indicates that two directory components were omitted for brevity (the full directory is /home/tao/data/mosaic/computer_helps). You can customize your prompt to display a variety of items (see man tcsh).
• Add set watch=(1 any any) to your .cshrc. This will force tcsh to inform you of when people log in/out of the computer you're using.
• (ADVANCED) Add setenv HOSTALIASES ~/.hosts to your .cshrc, and create a file ~/.hosts like the following:

  home-pc c662854-a.sttln1.wa.home.com
  spot spot.colorado.edu
  

  Well-behaved UNIX commands (ftp, telnet, X-windows) will honor these aliases.
• (ADVANCED) Add something like

  alias set_title 'echo -n "^[]2;"$HOSTNAME\:$tty"^G^[]1;"$HOSTNAME"^G"'
  

  to your .cshrc and

  if ($TERM != "ansi") then
    set_title
  endif
  

  to your .login. This will force tcsh to set your xterm/rxvt/dtterm/?? window title to the name of the computer you're logged on to. Note that it will not be reset when you log-out of a computer you've telnetted to. (You could put something in your .logout for that.) Note also that the ^[ and ^G above must be actual control-codes. You can enter them in Emacs by preceding the tricky character by ^Q. The check for $TERM != "ansi" is to protect the incompatible Microsoft telnet clients.
• Control-D has three different uses at the shell command prompt. If the command line is empty, Control-D will log you out (iff the shell variable ignoreeof is not set). Control-D when the cursor is at the end of the (non-empty) command line will list possible completions (filenames, shell variables, and environment variables), e.g.:

  warm:~>echo $t[Control-D]
  tcsh term tty  
  warm:~>echo $t
  

  The third use of Control-D is to delete the character under the cursor, if the cursor is not at the end of the line. It is also possible to invoke the completions-list mechanism from within a command line by preceding Control-D by Control-X. (Try these yourself.)

Netscape

• If you have selected a URL from, e.g. your mail program, you can just paste it almost anywhere into the document area of a Netscape window and it will go to that URL (i.e. instead of editing it into the Location: line at the top).
• If your destination URL is http://www.xyz.com, type just ``xyz'' in the Location box at the top of the screen. If it's http://www.yahoo.com/Science, type just ``yahoo/Science''
• Use shift+(left click) as a shortcut for ``Save Link As...''
• Use the middle mouse button to open a link in a new window.
• You can drag links from the document area of a Netscape window into your bookmarks, and into the document area of other Netscape windows.
• Hold down shift and click on ``Reload'' to reload the current document and all included objects (e.g. pictures).

ftp

• Use ``ftp'' instead of ``anonymous'' as your username when doing anonymous ftp.. easier to type.

wget, for retrieving remote groups of files quickly/easily

Wget is a command-line, non-interactive utility for retrieving remote files via ftp and http. Examples follow:

warm:~>wget www.cnn.com
--11:13:52--  http://www.cnn.com:80/
           => `index.html'
Connecting to www.cnn.com:80... connected!
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]

    0K -> .......... .......... .......... .......... ..........
   50K -> .......... ....

11:13:52 (187.33 KB/s) - `index.html' saved [66372]

warm:~>
warm:~>
warm:~>wget ftp://ftp.atmos.washington.edu/david/JBS_98.ps
--11:21:05--  ftp://ftp.atmos.washington.edu:21/david/JBS_98.ps
           => `JBS_98.ps'
Connecting to ftp.atmos.washington.edu:21... connected!
Logging in as anonymous ... Logged in!
==> TYPE I ... done.  ==> CWD david ... done.
==> PORT ... done.    ==> RETR JBS_98.ps ... done.
Length: 348,200 (unauthoritative)

    0K -> .......... .......... .......... .......... .......... [ 14%]
   50K -> .......... .......... .......... .......... .......... [ 29%]
  100K -> .......... .......... .......... .......... .......... [ 44%]
  150K -> .......... .......... .......... .......... .......... [ 58%]
  200K -> .......... .......... .......... .......... .......... [ 73%]
  250K -> .......... .......... .......... .......... .......... [ 88%]
  300K -> .......... .......... .......... ..........            [100%]

11:21:07 (501.53 KB/s) - `JBS_98.ps' saved [348200]

warm:~>
warm:~>
warm:~>mkdir lecturenotes
warm:~>cd lecturenotes/
warm:~/lecturenotes>foreach pagenumber (1 2 9 10)
foreach? wget http://www.atmos.washington.edu/my/class/lecture4/page${pagenumber}.ps
foreach? end
--11:27:18--  http://www.atmos.washington.edu:80/my/class/lecture4/page1.ps
           => `page1.ps'
Connecting to www.atmos.washington.edu:80... connected!
HTTP request sent, awaiting response... 404 Not Found
11:27:19 ERROR 404: Not Found.

--11:27:19--  http://www.atmos.washington.edu:80/my/class/lecture4/page2.ps
           => `page2.ps'
Connecting to www.atmos.washington.edu:80... connected!
HTTP request sent, awaiting response... 404 Not Found
11:27:19 ERROR 404: Not Found.

...

warm:~/lecturenotes>ls -l
-rw-rw-r--    1 fleminra uucp            0 Oct 26 11:28 page1
-rw-rw-r--    1 fleminra uucp            0 Oct 26 11:28 page10
-rw-rw-r--    1 fleminra uucp            0 Oct 26 11:28 page2
-rw-rw-r--    1 fleminra uucp            0 Oct 26 11:28 page9
warm:~/lecturenotes>
warm:~/lecturenotes>
warm:~/lecturenotes>wget 'ftp://ftp.data.org/pub/data*.ps'
If the filenames that you want have the form aaa.bbb.ccc.ddd.eee
you will need to use multiple wild cards aaa.*.*.*.eee  

warm:~/lecturenotes>

One of the above scripts uses the "foreach" loop and another uses a
"*" wildcard.  The following uses both.

foreach year ( 1982 1983 )
foreach month ( jan feb mar )
set filename=ftp://daac.gsfc.nasa.gov/data/avhrr/global_1dg/${year}/${month}/avhrrpf.ndvi.1nmegl.
wget $filename'*'
end
end
 
yields an output: 
--17:03:58-- -->
--ftp://daac.gsfc.nasa.gov/data/avhrr/global_1dg/1982/jan/avhrrpf.ndvi.1nmegl.*
           => `.listing'
Resolving daac.gsfc.nasa.gov... done.
Connecting to daac.gsfc.nasa.gov[192.107.190.139]:21... connected.
Logging in as anonymous ... Logged in!
==> SYST ... done.    ==> PWD ... done.
==> TYPE I ... done.  ==> CWD /data/avhrr/global_1dg/1982/jan
... done.
==> PORT ... done.    ==> LIST ... done.

    [ <=>                                                           ]
    1,357          1.29M/s             

17:04:00 (1.29 MB/s) - `.listing' saved [1357]

Removed `.listing'.

...

45 nino% ls 
avhrrpf.ndvi.1nmegl.8201.gz
avhrrpf.ndvi.1nmegl.8202.gz
avhrrpf.ndvi.1nmegl.8203.gz
avhrrpf.ndvi.1nmegl.8301.gz
avhrrpf.ndvi.1nmegl.8302.gz
avhrrpf.ndvi.1nmegl.8303.gz


Suppose you have lots of files to pull over.  Put the filenames in a
file, "file_of_filenames".
foreach filename ( `cat file_of_filenames` )
foreach? wget http://the URL of interest/$filename
foreach? end

For pulling over whole directories in situations where the "wget"
"times out": 
wget -q -O - http://domainname/directoryname/  | wget --forced-html -i -
The "-" in the first part tells wget to output to STDOUT, the "|" tells
the shell to pipe the output of the previous part to the next part,
the "-i -" in the second part tells wget to read from STDIN (the
STDOUT from the first part).  Sean Bailey of FUTURETECH / NASA GSFC
provided this very useful information.


For wget sessions timing out, one can also use
wget --tries=n --timeout=m http://...
where "n" is the number of times to try and "m" is the number of
seconds to wait before "timing out."  Harry Edmon provided this solution.

It is common now for data files to be written with one directory per
year of data.  To pull over just the data files, and not the directory
trees: 
wget -r http://directoryname --no-directories --accept nc 
This will also work for ftp.  The "accept" option says only bring over
files with the .nc extension.