Tricks and hints

trade14u · 03-26-2004, 01:12 PM

My favorite trick: Using the shell's { } expansion--

echo h{i,ello}
hi hello

the brackets are expanded with the letter(s) preceding the bracket one at a time. How is this useful? Copying files with long names!

cp thisisaverylongfilename.jar {, .bak}

makes:

cp thisisaverylongfilename.jar thisisaverylongfilename.jarBAK

Try it!

oneferna · 03-26-2004, 05:57 PM

In the bash shell you could also type the first few letters of the very long file name and then hit tab and it will fill it in for you, but your way is cool too, trade14u.

bluej · 03-27-2004, 03:14 AM

in bash, you can use C-r (control + r) to search in the command history.
for example, suppose you did a "less /usr/src/linux-2.6.4/Documentation/usb/usb-serial.txt" a couple of days ago, and you want to read the file again but you cannot remember the path anymore, only that the word 'serial' was in it. what you can do is search in your command history for the word 'serial' by pressing C-r, then typing 'serial'. the matching command line will be displayed as you type each letter. if the result is not yet the command you were looking for, then press C-r again to step back in your history until the right command appears, and press enter.

it's all on the man page, you can jump right there by searching for 'reverse'. there's also a list of other useful bindings, for example moving back/forward one word, deleting back/forward one word. these bindings are also good to memorize because they work in emacs too. (and that's actually how i found them in the first place, i thought i was in an emacs window, haha!)

slackmagic · 03-29-2004, 04:35 AM

hi there,

this is more likely known to a lot of linux users, but one of the things I always like to set up immediately after I've installed a new distro is change the .bashrc for root

this is how my /root/.bashrc looks like:

Code:

# .bashrc

# User specific aliases and functions

alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'

# Source global definitions
if [ -f /etc/bashrc ]; then
	. /etc/bashrc
fi

export PATH=$PATH:/sbin

export PS1="\\033[0;31m\u\\033[1;31m@\\033[0;31m\h\\033[1;31m:\\033[0;31m\w\\033[1;31m\\$\n: \\033[0;37m"

It's the RED code that I added. It pretty much reminds me ALWAYS whenever I'm logged on as root - you should give that a try :P

simple, but quite useful
(of course you can add many more changes to it)

jon1591 · 04-06-2004, 02:02 AM

Hi guys, I think this is a cool thread but I would like to know one about using &&. Is there any difference between doing:

Code:

make dep && make bzImage && etc...

or doing

Code:

make dep& make bzImage& etc...

Jon

AutOPSY · 04-06-2004, 03:09 PM

5) man manpage|col -b>manpage.txt
is usefull to redirect a rather big man page to a text file in easy readable format

This is also usefull for printer perfectly formatted man pages.

AutOPSY · 04-06-2004, 03:13 PM

Quote:

Originally posted by jon1591
Hi guys, I think this is a cool thread but I would like to know one about using &&. Is there any difference between doing:

Code:

make dep && make bzImage && etc...

or doing

Code:

make dep& make bzImage& etc...

Jon

& - forks a job to the background

&& is a boolean operator I belive. not sure exactly how to explain it but, simply
do && do && do

is 'do' and 'do' and 'do'
I guess thats a pretty hoakie explanation.

mikshaw · 04-06-2004, 04:11 PM

Quote:

Originally posted by AutOPSY
do && do && do

is 'do' and 'do' and 'do'
I guess thats a pretty hoakie explanation.

Close....

do ; do ; do
is 'do' and 'do' and 'do'

do && do && do
is 'do' and if successful then 'do' and if successful then 'do'

If the first 'do' fails, the others will not run. If the first 'do' is successful and the second 'do' fails, the third will not run.

jon1591 · 04-08-2004, 03:39 AM

Thanks for your help guys.

Jon

jon1591 · 04-26-2004, 03:05 PM

Hi again,
If you would like Num Lock to be switched on at boot-up add this to your rc.local:

Code:

 for tty in /dev/tty[1-6]; do
 /usr/bin/setleds -D +num < $tty
 done

Jon

naren · 05-13-2004, 10:30 AM

I m just subscribing to this thread ...
sorry for the in convenience caused.

bulliver · 05-13-2004, 01:42 PM

OK here's one someone might find useful. Have you ever wanted ls to print the permissions in numbers instead of "rwxr--r--" or whatever? Make this a shell alias:

Code:

 ls -l | sed -e 's/rwx/7/g' | sed -e 's/r--/4/g' | sed -e 's/r-x/5/g' | sed -e 's/rw-/6/g' | sed -e 's/---/0/g'

It won't work for every file, but it should for most normal files.

edit: this could be written more succinctly as:

Code:

 ls -l | sed -e 's/rwx/7/g' -e 's/r--/4/g' -e 's/r-x/5/g' -e 's/rw-/6/g' -e 's/---/0/g'

rickenbacherus · 06-16-2004, 06:17 PM

I always thought aliases resided in memory so I prefer to write small scripts and place them in /usr/bin. Example. I have a box named cromag that I frequently ssh into.
touch cromag && echo "ssh user@192.168.1.125" > cromag && chmod +x cromag
sudo mv cromag /usr/bin

To find your current resolution:
xvidtune -show
OR
xrandr|grep \*

To enable/disable energystar features:
xset +/-dpms

If you're a bad typist like me and commonly transpose your last two letters of a command you can use CTRL+T to switch them like so:

apt-gte
CTRL+T
(now your typo gets corrected)
apt-get

Joey.Dale · 06-16-2004, 10:06 PM

no &&=if no error do this while ; just starts l a new comand

-Joey

freakyg · 05-02-2005, 12:09 PM

I'll add to what retiredsoldier posted............In my ~/.bashrc I like to define all the colors first, then export them so my PS1 is a little easier to create............

Code:

 
# Color Variables for Prompt
GRAD1='\333\262\261\260'
GRAD2='\260\261\262\333'
YLOBRN='\[\033[01;33;43m\]'
WHTBRN='\[\033[01;37;43m\]'
REDBRN='\[\033[01;31;43m\]'
BLUBRN='\[\033[01;34;43m\]'
GRNBRN='\[\033[00;32;43m\]'
REDBLK='\[\033[00;31;40m\]'
PPLBLK='\[\033[01;35;40m\]'
WHTBLK='\[\033[01;37;40m\]'
NONE='\[\033[00m\]'
HBLK='\[\033[00;30;30m\]'
HBLU='\[\033[01;34;34m\]'

BLU='\[\033[01;34m\]'
YEL='\[\033[01;33m\]'
WHT='\[\033[01;37m\]'
PRPL='\[\033[00;35m\]'
RED='\[\033[01;31m\]'
GRN='\[\033[01;32m\]'          
GRAY='\[\033[01;30m\]'
PINK='\[\033[01;35m\]'
NORM='\[\033[01;00;0m\]'
CYAN='\[\033[01;36m\]'


export GRAD1 GRAD2 YLOBRN WHTBRN REDBRN BLUBRN GRNBRN REDBLK PPLBLK WHTBLK NONE HBLK HBLU BLU YEL WHT PRPL RED GRN GRAY PINK NORM CYAN

# what I use for normal users
PS1="$CYAN[\s]$YEL[\t] $GRN\u$YEL@$BLU\h $WHT[\w]\$$NONE $NORM"

try it out............