Sam's Long Random List of Unix Notes
Unix is one ugly duckling. It's also awesome. I don't care
what anyone says, maybe it isn't for everyone, but it's hard
not to admire something about it. I've used Unicies of
various kinds and I love 'em all. Trouble is my memory's spotty
as hell. So when I come across something in the Unix world I
just love, I try and jot it down here. I also jot down other
notes and craziness regarding things less Unix centric, such as
Python notes or Firefox notes.
Organization's not my strong point. Good luck readin' this.
I hope you find it useful.
I use GNU emacs where I can get away with it (It's damn hard
sometimes, it often won't come on small boot-able Linux systems
of which I surprisingly find myself in from time to time, in
which case it's often Nano or *GASP* a vi-flavor-of-the-month).
My problem is I often forget the emacs-lisp incantations I like
to keep in my .emacs file, so here's my safe,
simple, emacs file in case I need it, as well as my
Elisp libraries I use, and here's a list
of common emacs lisp settings and lore I can't live without and
can't often remember :-D. I often find I need to spend time
tweaking gnu emacs when I load it up for the first time on a
system, so I've set this place up as my cheat sheet, and emacs
I can't emphasis enough how useful the Emacs Wiki is to us Emacs
users. It's invaluable and a far cry better than these loose
- WHEN IN DOUBT, LAUNCH MR. EMACS WITH "-q" AND
COMPLETELY DISREGARD A TERRIBLE BROKEN STARTUP FILE, USE
--no-site TO RUN EMACS WITHOUT CUSTOM SITE-WIDE
- Remember, for Emacs novices, you can use the menu, even
in a terminal. F10 will get you to the menu, but if the
terminal emulator you're using doesn't let you send f10, you
push ESC ` instead. There's lots of useful
functions you can access easily from the menu, and if one of
them happens to be bound to a keyboard shortcut, it'll tell
you what it is after using it.
- (setq backup-directory-alist '(("." .
"~/.my_backups"))) Helps keep those backup files
from cluttering your directories. Make sure the directory
- M-x normal-erase-is-backspace to fix the
inevitable backspace problems one faces when jumping between
Mac PC environments and terminal emulators.
- Saving editing sessions is incredibly useful
the .emacs file. Don't forget to save your session the first
time with M-x desktop-save and don't forget
to start Emacs in the same directory as before!
- (setq dired-recursive-copies t) and (setq
dired-recursive-deletes t) to copy and delete
recursively in Dired (Emacs' DIRectory EDitor).
- Rings are incredible things in Emacs, never forget about
them! There's the kill ring, the search ring, and the mark
ring. To cycle through the kill ring C-y then
M-y to cycle through the last few things
killed in the current buffer. They're always there until the
kill ring runs out of room, and it'll keep looping, so it's a
great robust way to save text. The mark ring is perhaps the
most under used and under appreciated feature of Emacs in my
opinion. You can set the mark with
C-<SPC> which will also allow you to
set the region by moving the point, but you can also move
back to the mark and cycle through all your recent marks in
the current buffer with C-u
- Macros, Macros, and more Macros. Never forget about
Macros. C-x ( to start one, and C-x
) to finish it off. C-x e to execute
it. C-u C-x ( to execute and add more to it.
M-x name-last-kbd-macro to name it for later.
C-x C-k Edit a previously defined keyboard
macro, and M-x
apply-macro-to-region-lines to run it over your
highlighted region. There's an elisp package "kmacro.el" that
provides even more macro goodness including a Macro ring. And
don't forget M-x insert-kbd-macro, I have a
tendency to write useful macros out to a hidden file in the
working directory of a project called ".macros.el" so I can
load 'em later. If you want to make a named keyboard macro
the current keyboard macro, just define another macro and
call the macro via M-x
- Dired is awesome once you get used to it. I've heard that
people who despise Emacs will use it. It's the ultimate tool
to clean up Emacs' poo (backup files, auto-save files, etc.);
search the contents of each file in a directory structure for
a regular expression; copy, compress and make backups; load
and compile elisp libraries; and batch rename files. Pop into
a directory with C-x C-f. Use this awesome
sequence of commands to rename a series of files based on
- Emacs is the ultimate BBEdit
for unix when it comes to converting ascii formats and
character sets. C-x RET f let's you change
what format the text you're working on is for writing. A
super quick way to convert Mac->PC->Unix Ascii.
- Man can type any character in the Emacs world by quoting
it with C-q. The rest is up to your terminal emulation
software and its ability to send that character..
- Info-directory-list is a useful variable
for maintaining locally installed Info documentation. If you
don't have root on a machine, it's impossible to install Info
documentation site wide so you'll need to use this variable.
However, the better mechanism is to set the INFOPATH
environment variable. This can be tricky, because you need to
explicitly point INFOPATH to site-wide directories as well.
Mine looks like this on the SDF:
Sed, Awk, tr
I don't normally touch these tools, but here's a few
invaluble one-liners that have gotten me out of more than a few
- ssh -L <localport>:<tunneled remote
host>:<port on remote host> user@host --
The magical incantation for local port forwarding.
- ssh -R <remoteport>:<tunneled local
host>:<port on local host> user@host --
Basically the opposite of -L, a great way to get into a
machine behind a firewall if you have local access. Just ssh
out from it to your home computer, or a computer with ssh
access. Leave the connection open and then tunnel right back
- scp <localfile>
- The follow is pretty much how I always use rsync to
update conf files between machines: rsync -r -tv
--delete-after -e ssh localdir1 localdir2 ... localdirn
user@host:.. Turns on recursion, preservation of
timestamps, verbose output, delete-files not present on the
local machine, and use ssh.
- wget --no-host-directories/-nH I think
this is an annoying default, but I guess it aint all bad, it
does help keep things a bit safer and accounted for. None the
less I like to get rid of 'em quick like. In fact I often
alias wget='wget -nH' in Bash.
- wget -m for mirror mode. If I'm pulling
down more than one thing off the web I generally use
- You almost always want to call wget with -np which stands
for No Parent and means that you don't recurse higher than
the first directory fed to wget. Trust me on this one, it can
be very bad.