DZone Snippets: bash code

WWAN Dialer

jmcvetta (Jason McVetta) — Sun, 11 May 2008 18:21:21 GMT

This script dials the built-in Verizon WWAN (mobile broadband) modem on my Thinkpad T61.



#!/bin/bash

#

# Dial the WWAN

#



hang_up () {

    echo 

    echo 'WWAN deactivated'

    echo

    exit

}



trap "hang_up" 2



echo 'Activating WWAN'

sudo modprobe -r airprime usbserial

sudo modprobe usbserial vendor=0x1199 product=0x0220

sudo modprobe airprime

sleep 0.5

sudo wvdial

Howto resize multiple pictures, graphics, images

Tue, 29 Apr 2008 16:41:33 GMT



for k in $(ls *.jpg); do convert -resize 800 -quality 80 $k r800-$k; done

Bash title random Quote routine

robotsu (Gavin) — Thu, 24 Apr 2008 19:43:08 GMT

#
#this is a script in my .bash_profile that gets a random
#quote .txt file and assigns it to the terminal title.
#

quote_path="/Users/glynch/Documents/quotes/*"
files=($quote_path)
N=${#files[@]}
((N=RANDOM%N))
randomfile=${files[$N]}
quote=""
while read line; do quote="$quote $line"; done < $randomfile
echo -n -e "\033]0;$quote\007"

One-line web server in Ruby

ntk () — Wed, 23 Apr 2008 13:22:36 GMT





# From: http://www.ntecs.de/blog/articles/2008/02/09/the-worlds-smallest-webserver

# Author: Michael Neumann

# ... point your browser to http://localhost:3125/etc/motd



ruby -rsocket -e 's=TCPServer.new(5**5);loop{_=s.accept;_<<"HTTP/1.0 200 OK\r\n\r\n#{File.read(_.gets.split[1])rescue nil}";_.close}'

Sort last 1000 shell commands by popularity

sikelianos (Zeke Sikelianos) — Tue, 22 Apr 2008 04:16:17 GMT



  history 1000 | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head

Bashy Perlness for generating Favicon text for OpenSearches

sikelianos (Zeke Sikelianos) — Mon, 21 Apr 2008 19:58:49 GMT



echo -n 'data:image/xicon,' ; perl -ne 's/(.)/"%".unpack("H2",$1)/egs; print' ~/Desktop/favicon.ico ; echo ''

Changing the Bash prompt

jrobertson (James Robertson) — Fri, 11 Apr 2008 22:43:21 GMT

The following shell command changes the bash prompt from this "james@cryton:~/projects/pear_housekeeping2/housekeeping$" to this "james@cryton> "



export PS1="\n\u@\H>"

I tried the above example on Ubuntu 7.10.

Reference:
Tip: Prompt magic [ibm.com]
Bash Prompt HOWTO [tldp.org]

Batch re-size a collection of images from the command line

27stars (27stars) — Tue, 01 Apr 2008 09:33:24 GMT



for img in $(ls *.png); do convert $img -resize 75% smaller-$img; done;

Block many users in a system v0.1.1

Sun, 02 Mar 2008 14:23:38 GMT

Block many users in a system using a text file as argument



#!/bin/bash



#******************************************************************************#

# BlockManyUsers.sh - Block many users in a system using a text file           #

#                       as argument                                            #

#   Copyright (C) 2008 - written by flynets - autisticiorg>   #

#   BlockManyUsers is free software: you can redistribute it and/or modify     #

#   it under the terms of the GNU General Public License as published by       #

#   the Free Software Foundation, either version 3 of the License, or          #

#   any later version.                                                         #

#                                                                              #

#   BlockManyUsers is distributed in the hope that it will be useful,          #

#   but WITHOUT ANY WARRANTY; without even the implied warranty of             #

#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the               #

#   GNU General Public License for more details.                               #

#                                                                              #

#   You should have received a copy of the GNU General Public License          #

#   along with this program.  If not, see .      #

#******************************************************************************#



# Checks if you have the right privileges

if [ "$USER" = "root" ];then

   # Checks if there is an argument

   [ $# -eq 0 ] && { echo >&2 ERROR: You may enter as an argument a text file containing users, one per line. ; exit 1; }

   # checks if there a regular file

   [ -f "$1" ] || { echo >&2 ERROR: The input file does not exists. ; exit 1; }

   TMPIN=$(mktemp)

   # Remove blank lines and delete duplicates

   sed '/^$/d' "$1"| sort -g | uniq > "$TMPIN"

   

   NOW=$(date +"%Y-%m-%d-%X")

   LOGFILE="BMU-log-$NOW.log"



   for user in $(more "$TMPIN"); do

      # Checks if the user already exists.

      cut -d: -f1 /etc/passwd | grep "$user" > /dev/null

      OUT=$?

      if [ $OUT -eq 0 ];then

         # block selected user

         /usr/sbin/usermod -L "$user"

         # save user info in a file

         echo The user \"$user\" has been blocked. >> "$LOGFILE"

      else

        echo >&2 Error the user account \"$user\" doesnt exists! >> "$LOGFILE"

      fi

   done

   rm -f $TMPIN

   exit 0

else

   echo >&2 ERROR: You must be a root user to execute this script.

   exit 1

fi

exit 0

Convert files to avi

scvalex (Alexandru Scvortov) — Fri, 29 Feb 2008 12:58:02 GMT

Bash one-liner that converts all *.flvs in the current directory to .avis.

Note: To convert something else, just change the .flv extension.



for i in *.flv; do mencoder -ovc lavc -oac mp3lame -o "$i.avi" "$i"; done