Console / shell tips & tricks

[Caffeine]

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nd() { test -d "$1" || mkdir "$1" && cd "$1" ; }
alias o="less -iMS"
nX()
{
  for i in `seq 0 9`
  do
    if [ ! -e "/tmp/.X${i}-lock" ] ; then
      XFree86 ":$i" -query localhost &
      break
    fi
  done
}

the last one, nX, starts a new X login on a new display. (You should add localhost to /etc/X11/xdm/Xaccess)

I can't get this to work...
The nX function starts a new X window, but I get no login prompt (gdm, in my case).
Am I doing something wrong? I tried to add just 'localhost' in Xaccess. Should I add something more? I also tried to add CHOOSER localhost, but that didn't work either.
Maybe I'm just stupid... But I would really like this to work, so any help is very appreciated!

I'm having the same problem. What's the correct entry in Xaccess?

[Jarjar]

For killing wine(x) when it ... fucks up.

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/usr/bin/killall-that-contains: (can't think of a name; help me!)
#!/bin/sh
if [ $1 == "-9" ]
then
        for i in $(ps aux|grep $2|grep -v grep|cut -c10-15)
        do
                kill -9 $i
        done
else
        for i in $(ps aux|grep $1|grep -v grep|cut -c10-15)
        do
                kill $i
        done
fi

Warning: Bash scripting newbie.
The only alias I use, except for ll/ls (--color=yes --show-control-chars) is
alias startx='startx -- -dpi 100'

Edit: Oopsie! I reversed the if and else; it kill -9'ed if you told it not to and the other way around...fixed.

[guero61]

My few toys that are useful outside of the private networks I use --

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alias psg="ps -awef |grep"
alias psu="ps -u"
alias ct="tar -cvzf"
alias xt="tar -xvpf"
alias xzt="tar -xvzpf"
alias xjt="tar -xvjpf"
alias ll="ls -lF --color"
alias lla="ls -laF --color"
alias r="fc -s"

set -o vi

Those, and I love using "cd -", it saves so much typing!

[Jimbow]

Here are some (hopefully) non-dups:

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alias snice="sudo nice -n 5"
alias smerge="snice emerge"
alias kern="snice make dep && snice make clean bzImage modules modules_install"

loc () {
    locate -i $@ | grep -v ^/usr/portage | grep -v ^/var
}

burn () {
    sudo cdrecord -v speed=4 dev=0,0,0 -data $1
}

start () {
    nohup $@ &
}

#-------- long ls listings /w pager --------
ll  () { ls -lF   $@ | more;}
lla () { ls -lAF  $@ | more;}
llt () { ls -lAFt $@ | more;}

#-------- clean: removes emacs *~ and #*# files --------
clean () {
    if [[ "$#" == "0" ]] ; then set '.'; fi;
    for dir in $@; do
        if [[ -d $dir ]]; then
            rm -f ${dir}/*~ $dir/#*#;
        else
            echo "clean: missing directory '${dir}'"
        fi
    done;
}

#-------- li: ls -F if directory, less if file --------
li (){
    if [[ -d $1 ]] ; then
         ls -F $1;
    elif [[ -f $1 ]] ; then
        less $1;
    else
        ls -F $1
    fi
}

[Yarrick]

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ls -h

can also be useful. It displays file sizes as human-readable, using giga/mega/kilo/bytes for size instead of just bytes.

somtimes i miss an alias to mkdir && cd a new folder... havent written one yet though.

[morgap98]

i can't get my laptop to parse the .bashrc file. The only time that i can make changes to my bash prompts are through the /etc/profile script.

NOTE: if i type "bash" [enter] then it will parse my .bashrc,

how can i get this to automatically happen, i don't think i should be modifiying my /etc/profile script like this!!!

</P33T>

[BackSeat]

For those unfamiliar with ^R reverse search in bash, here's an extra tip. After ^R type a few characters and the command line that contained those characters will be shown. Type ^R again at that point, and the search will continue back through the history.

For those aliasing ls='ls --color' you might prefer to use

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lss='ls --color=auto'

That way the coloUr escape sequences are only sent if the output is connected to a terminal (so sending the output of ls to a file doesn't result in embedded escape sequences.

In a similar way, I alias grep:

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alias grep --color-auto

which highlights the matching pattern in the output. Try it: you'll never want to be without it.

Finally (for now), if you think 'less' is just a way of paging through a file, read the man page. There is more flexibility in this program than a lot of people realise.

BS

[Redson]

Not really a "trick", but here's something I put in my bashrc:

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fortune

Great way to start the day [/code]

That is awesome! You inspired me to write my first pseudo bash script!!!!
It essentially picks a certain type of fortune depending on what day it is.
I put it in my bashrc:

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NUMBER_OF_FORTUNES=3
DATE=`eval date +%d`  #Produces only the date Number.

let "DATE=$DATE%$NUMBER_OF_FORTUNES"

case "$DATE" in
	[0]  ) fortune;; #Random fortune
	[1]  ) fortune /usr/share/fortune/starwars;;  #Quoute from Star Wars
	[2]  ) fortune /usr/share/fortune/homer;;  #Quote from Homer
esac

note that to do this you need to
emerge fortune-mod-homer
emerge fortune-mod-starwars

I would also recommend doing emerge -s fortune for a list of other cool fortune files.

[Redson]

i can't get my laptop to parse the .bashrc file. The only time that i can make changes to my bash prompts are through the /etc/profile script.

NOTE: if i type "bash" [enter] then it will parse my .bashrc,

how can i get this to automatically happen, i don't think i should be modifiying my /etc/profile script like this!!!

</P33T>

Hello fellow N00B! I had this problem for a while, fortunately somebody finally told me you have to put

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[ -f ~/.bashrc ] && source ~/.bashrc

at the end of your .bash_profile so it reads your .bashrc

After doing that I think you have to do

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source .bash_profile
env-update

though I'm not sure about that. Then remember to restart your shell before the .bashrc takes effect

[ebrostig]

Since we are all sharing and beeing very happy in this thread, I thought I was going to add to the confusion

Here is my .bash_profile

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alias ls="ls --color=auto"
alias l="ls -l "
alias lm="ls -l| more"
alias la="ls -a "
alias llm="ls -la | more"
alias ln="ls -lLt | more"
alias cdo="cd $ORACLE_HOME"
## LS_COLORS should be on one line, broken up here as not to mess up phpBB too much :)
export LS_COLORS='no=00:fi=00:di=01;34:ln=00;36:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:
or=40;31;01:ex=00;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.zip=01;31:*.z=01;31:
*.Z=01;31:*.gz=01;31:*.bz2=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.jpg=01;35:*.jpeg=01;35:
*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:
*.tif=01;35:*.tiff=01;35:*.png=01;35:*.mpg=01;35:*.mpeg=01;35:*.avi=01;35:*.fli=01;35:*.gl=01;35:
*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.ogg=01;35:*.mp3=01;35:*.wav=01;35:';
alias grep="grep --color=auto"
shopt -s cdspell 
shopt -s cdable_vars
shopt -s checkhash 
shopt -s checkwinsize 
shopt -s mailwarn
shopt -s sourcepath
shopt -s no_empty_cmd_completion
shopt -s histappend histreedit
shopt -s extglob

shopt -s extglob	# necessary

complete -A hostname   rsh rcp telnet rlogin r ftp ping disk ssh
complete -A command    nohup exec eval trace strace gdb
complete -A command    command type which 
complete -A export     printenv
complete -A variable   export local readonly unset
complete -A enabled    builtin
complete -A alias      alias unalias
complete -A function   function
complete -A user       su mail finger

complete -A helptopic  help	# currently same as builtins
complete -A shopt      shopt
complete -A stopped -P '%' bg
complete -A job -P '%'     fg jobs disown

complete -A directory  mkdir rmdir

complete -f -X '*.gz'   gzip
complete -f -X '!*.ps'  gs ghostview gv
complete -f -X '!*.pdf' acroread
complete -f -X '!*.+(gif|jpg|jpeg|GIF|JPG|bmp)' xv gimp

function lowercase()  # move filenames to lowercase
{
    for file ; do
        filename=${file##*/}
        case "$filename" in
        */*) dirname==${file%/*} ;;
        *) dirname=.;;
        esac
        nf=$(echo $filename | tr A-Z a-z)
        newname="${dirname}/${nf}"
        if [ "$nf" != "$filename" ]; then
            mv "$file" "$newname"
            echo "lowercase: $file --> $newname"
        else
            echo "lowercase: $file not changed."
        fi
    done
}

function xtitle () 
{ 
    case $TERM in
	xterm* | dtterm | rxvt) 
	    echo -n -e "\033]0;$*\007" ;;
	*)  ;;
    esac
}

alias top='xtitle Processes on $HOST && top'
alias eworld='xtitle Emerge update world && emerge -u --deep world'
alias esync='xtitle Emerge rsync in progress && emerge rsync'
alias ncftp="xtitle ncFTP ; ncftp"
alias splus="xtitle SQL*Plus && sqlplus \"/ as sysdba\""

Erik

[balk]

Finally (for now), if you think 'less' is just a way of paging through a file, read the man page. There is more flexibility in this program than a lot of people realise.

BS

How often I press '/' in any other program when trying to search for a word! Should be implemented in every browser too. Less rules

I also curse on Windows when I try to alt-drag a window... nice features

[grant.mcdorman]

Code: Select all

nX()
{
  for i in `seq 0 9`
  do
    if [ ! -e "/tmp/.X${i}-lock" ] ; then
      XFree86 ":$i" -query localhost &
      break
    fi
  done
}

the last one, nX, starts a new X login on a new display. (You should add localhost to /etc/X11/xdm/Xaccess)

I can't get this to work...
The nX function starts a new X window, but I get no login prompt (gdm, in my case).
Am I doing something wrong? I tried to add just 'localhost' in Xaccess. Should I add something more? I also tried to add CHOOSER localhost, but that didn't work either.
Maybe I'm just stupid... But I would really like this to work, so any help is very appreciated!

You need to do several things to get this to work.

First off, most display managers - especially kdm and gdm - are configured to ignore the -query (technically, it's XDMCP Query). You need to modify your window manager configuration file.

Display manager configuration

For kdm, it is in /usr/kde/3.1/share/config/kdm/kdmrc (the 3.1 will vary, of course, if you're running a release other than 3.1.x). In this file you will find:

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[Xdmcp]
# Whether KDM should listen to XDMCP requests. Default is true.
#Enable=false
# The UDP port KDM should listen on for XDMCP requests. Don't change the 177.
#Port=177
# File with the private keys of X-terminals. Required for XDM authentication.
# Default is ""
#KeyFile=/usr/kde/3.1/share/config/kdm/kdmkeys
# XDMCP access control file in the usual XDM-Xaccess format.
# Default is /usr/kde/3.1/share/config/kdm/Xaccess
# XXX i'm planning to absorb this file into kdmrc, but i'm not sure how to
# do this best.
Xaccess=/etc/X11/xdm/Xaccess

Make sure that the 'Enable=false' line is commented out, and the 'Xaccess=/etc/X11/xdm/Xaccess' is not commented out.

For gdm, please check this next section; I don't have gdm installed. However, according to the online references I can find, its configuration files are in /etc/gdm/Init/gdm.conf.

In this file, set it up as follows:

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[xdmcp]
Enable=1

I can't see a configuration for Xaccess, so presumably it uses the standard one.

Xaccess configuration
For most purposes, you just need to add the following line to /etc/X11/xdm/Xaccess:

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*

That's it (one asterix). You can make it more restrictive - the comments in the file should be adequate.

The nX function should now work.

Note, by the way, that there is a hole in this script: the presence of the /tmp/.Xn-lock is not a 100% guarantee that there's a server running, as this file might be left around if the server crashes.

Important: Firewalling
Be sure to have UDP port 177 closed on your firewall (if it's a sensible firewall, you have to explicitly open ports). The protocol used - XDMCP - is not that secure; in addition, if you use the Xaccess setup I've suggested your display manager will offer login windows to any X display - including random unknown ones on the Internet, if they can get at ports 177 and 6000 on your machine.

[nephros]

oh well, I might just add to that:

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alias dir="echo NO SUCH FILE OR DIRECTORY"
alias x="startx"
alias y="startx -- :1"
alias h="history"
alias ..="cd .."
alias cd..="cd .."
alias ...="cd ~"
alias nano="nano -w -T 4"
alias pico="nano -w -T 4"

and for root:

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alias unmerge="emerge unmerge"
alias semerge="screen emerge"

also note that you can prefix any command with a \ backslash to escape any aliases you have set. So \pico would launch a real pico instead of the nano alias...

[flickerfly]

If you haven't noticed, the left and right windows keys on your keyboard will change you to the virtual terminal to the left and right of your current one. Nice.

How? I use fluxbox, you?

[carambola5]

If you haven't noticed, the left and right windows keys on your keyboard will change you to the virtual terminal to the left and right of your current one. Nice.

How? I use fluxbox, you?

For fluxbox, put this in your ~/.fluxbox/keys

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...
None Super_R :NextWorkspace
None Super_L :PrevWorkspace
...

Other fun keys mods are (assuming a multimedia keyboard):

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None XF86AudioPlay :ExecCommand xmms -t
None XF86AudioStop :ExecCommand xmms -s
None XF86AudioPrev :ExecCommand xmms -r
None XF86AudioNext :ExecCommand xmms -f
None XF86AudioLowerVolume :ExecCommand ~/bin/changevol d
None XF86AudioRaiseVolume :ExecCommand ~/bin/changevol u
None Print :ExecCommand ~/bin/screenie

where changevol is (I removed my muting code because I'm not sure if it works or not):

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#!/bin/bash
case $1 in
  "d") aumix -v-2
    ;;
  "u") aumix -v+2
    ;;
  "*") echo "Error"
esac

and screenie is:

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#!/bin/bash
PICPATH=$HOME/pictures/screenshots
if [ -f "$PICPATH/index.dat" ]; then echo 1 > $PICPATH/index.dat; fi
INDEX=`cat $PICPATH/index.dat`
import -window root $PICPATH/ss$INDEX.png
echo $(($INDEX + 1)) > $PICPATH/index.dat

(I think that'll work)

[Brandy]

I find it remarkable how many people don't use the history command. That, combined with the '!n' to re-issue a frequently-used command saves me tons and tons of time.

I agree. The history is sometimes very useful. You can also use it to fix spelling mistakes.
Let's say you want to add a new user:

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root@dante / # usradd -m -c "Brandy Westcott" brandy -g users -G wheel,portage -s /bin/bash
bash: usradd: command not found

hmm... bad spelling. No problem:

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^sr^ser
useradd -m -c "Brandy Westcott" brandy -g users -G wheel,portage -s /bin/bash

^string1^string2 is really just the same as !!:s/string1/string2

Ciao, Brandy

[flickerfly]

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...
None Super_R :NextWorkspace
None Super_L :PrevWorkspace
...

Thanks, I don't have a multimedia keyboard here though. This will be nice to work with and I'll keep the multimedia stuff in memory for later. Thanks.

[burmashave]

Wow, this is a superb thread! I've been using Linux for about 2 years now; however, I couldn't figure out how the power users got by without using some gui tools.

I've added "history" and "ls" commands to my bashrc, and also added fortune. Thanks for all the above suggestions.

I often find myself grepping about for files, and the only find command I can remember is "find --iname", so I wrote a script to handle my find operations:

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#! /bin/sh

# findfile -- a utility for finding files and directories

PATH=/usr/bin:/bin; export PATH

case $1 in 
	fn) find -iname $2 -print 2>/dev/null | more;;
    fs) find -size +$2k -print 2>/dev/null | more;;
    fm) find -cmin -$2 -print 2>/dev/null | more;;
    fd) find -iname $2 -type d -print 2>/dev/null | more;;
    fds) du -m * 2>/dev/null | sort -rn | head -$2;;
    ffs) PERCENTAGE=$2
		df -kl | grep -iv filesystem |  awk '{  print $6" "$5} '| while
		 	read LINE; do
  			PERC=`echo $LINE | cut -d"%" -f1 | awk '{  print $2 } '`
  			if [ $PERC -gt $PERCENTAGE ]
            	then
    			echo $LINE  
  			fi
         	done;;
	fbad) find . -type l -print 2>/dev/null | perl -nle '-e || print';;
    f) echo "findfile usage:"
       echo 
	   echo "fn <name>   find file <name>, case insensitive, errors suppressed, wildcards OK"
	   echo "fs <n>      find file greater than <n> kilobytes"
	   echo "fm <n>      find file modified within last n minutes"
	   echo "fd <name>   find directory <name>, case insensitive"
	   echo "fds <n>     find top <n> directories, based on diskspace usage (in megabytes)"
	   echo "ffs <n>     find file systems with usage greater than <n> percent"
	   echo "fbad        find bad symlinks"
	   echo "f           list findfile options"
	   echo
    esac

Then, I added the following aliases to bashrc:

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alias fn="findfile fn"
alias fs="findfile fs"	
alias fm="findfile fm"
alias fd="findfile fd"	
alias fds="findfile fds"
alias ffs="findfile ffs"
alias fbad="findfile fbad"
alias f="findfile f"

I put the findfile script in PATH, and now I can find files using a short command, or simply enter "f" to get a list of my find options:

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admin@cruise admin $ f
findfile usage:
 
fn <name>   find file <name>, case insensitive, errors suppressed, wildcards OK
fs <n>        find file greater than <n> kilobytes
fm <n>        find file modified within last n minutes
fd <name>  find directory <name>, case insensitive
fds <n>       find top <n> directories, based on diskspace usage (in megabytes)
ffs <n>       find file systems with usage greater than <n> percent
fbad            find bad symlinks
f                 list findfile options

As my title implies, I am a noob, so I would welcome any suggestions about my script.

Another thing I put in bashrc is an alias for my SSH connections:

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alias myserver="ssh -l admin xxx.xxx.xxx.xxx" # ssh to server

If you're using a key to authenticate, the command "myserver" will automatically initiate a session.

[thadk]

Quick Question: How can you make any process run like a daemon. I.e. how can you run a process and then close the xterm window or ssh session and still have the process run in the background.

Also I have a tip: To search through files looking for specific content you can use:

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$ find . -exec grep -H [search-string] {} \;
OR
$ grep -R [search-string] *

[scap1784]

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alias burn="cdrecord -vv speed=8 dev=0,0,0  -eject "

I also made a few 4 letter words aliases for fortune so when my friends get on here and get mad at the computer it talks back! kinda a stress reiliver i guess

[viperlin]

probably THE most usefull one ever:

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alias lsd="ls --color -d */"

try it, it's lovely and really usefull in those massive directory's.

[vers_iq]

dumb question, but how is the hisory better than just cycling through the list with the up arrow? Seems like you would have to read thru the list anyway

The function of history is not only to repeat a certain command, but it's most useful to keep track the chain of command line in certain console. expecially if u are in the middle of a task which requires u to enter command inputs in particular order.

[Bellrang QT]

Probably another dumb question...

Is there a way to control what shows up in the titlebar of Putty? When I emerge (using an ssh session with Putty), the titlebar is changed. When emerge is done, the titlebar just displayed "xterm".

When I ssh into my RedHat box, it shows user@machine... that's kinda nice.

Any ideas?

[nico--]

Quick Question: How can you make any process run like a daemon. I.e. how can you run a process and then close the xterm window or ssh session and still have the process run in the background.

Use &:

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mpg123 mylegallyrippedmp3file.mp3 &

If you leave the xterm open you still get output from the program... you have to redirect the output to /dev/null but i can't remember how to do that, heh.

[thadk]

No, I'm pretty sure that a backgrounded(&) process dies when it's parent (the xterm/ssh session) does. I'm trying to figure out how to make it so the parent is pid 1 (at least thats the definition of a daemon I found)

With kde I can sort of do what I want with `kdeinit`