Convert string to hex.

If you want to use snoop or tcpdump with advanced search in the packet, then you would need to convert the string to hex string. For this, either you can use a web search and find some web application to do that or you can use a simple C program like this 🙂

/*
* =====================================================================================
*
*       Filename:  ascii.c
*
*    Description:  ascii to dec
*
*        Version:  1.0
*        Ceated:  03/02/2012 12:08:49 PM
*       Revision:  none
*       Compiler:  gcc
*
*         Author:  Amit Agarwal (aka), amit.agarwal@roamware.com
*  Last modified: Thu Mar 08, 2012  08:47PM
*
* =====================================================================================
*/
void main (int argc, char **argv){
    int i=0;
    char a[200]="",b[200]="";
    printf("String - %s, Length - %d\n",argv[1],strlen(argv[1]));
    /*printf("%x\n 0x",argv[1]);*/
    while (i < strlen(argv[1])){
        /*printf("%c",argv[1][i]);*/
        sprintf(a,"%s%x",a,argv[1][i]);
        /*printf("a=%s\n",a);
        printf("b=%s\n",b);*/
        sprintf(b,"%s%d",b,argv[1][i]);
        i++;
    }
    printf ("\n");
    printf ("String : %s\n",argv[1]);
    printf ("Hex    : 0x%s\n", a);
    printf ("Dec    : %s\n", b);

}

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glances – Get a glimpse of the whole system

You would have used top at some point of time. Did you not wish that instead of just the processes it list all the vital statistics of the system as a whole. How good it would be to see the Memory, Net, Processes and Disk usage on the same screen. Well then you should take a look at glances. Here is how it looks:

[][1]

For using this tool, here is what you need to do :

Get yourself som new themes for vim

Well, you would already have some themes for your vim, by default. And if you did not like them then you would have added some of your own too (downloaded from vim.org). But, those are something, that you might not still like and want to make some changes.

Here’s, a new way to do it. Just go to the link mentioned below and click on Generate Dark or Generate Light. You can generate as many as you like and once you like the theme, simply click on vim in the bottom and download 🙂 BTW, you can generate textmate and Emacs theme as well.

Rekursive Grep on Solaris or AIX Systems without GNU egrep -r funcionality

If you work regularly on a Solaris or systems which do not have the “-r” (recursive grep) for grep, then you know what a lifesaver this command can be.

Here is one from command line fu:

find . -type f -exec awk '/linux/ { printf "%s %s: %s\n", FILENAME, NR, $0; }' {} \;

The benefit of using awk here is that you can print the line number also 🙂

Linux hardware details.

Here is one of the scripts that I found on the net while searching for something … Note the URL for the script in the Description.

#!/bin/bash -
#===============================================================================
#
#          FILE:  linux_hw.sh
#
#         USAGE:  ./linux_hw.sh
#
#   DESCRIPTION:  http://www.howtogeek.com/howto/solaris/get-the-processor-type-on-solaris/
#
#       OPTIONS:  ---
#  REQUIREMENTS:  ---
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR: Amit Agarwal (aka), amit.agarwal@roamware.com
#       COMPANY: Roamware India Pvt Ltd
#       CREATED: 09/13/2011 03:57:34 PM IST
# Last modified: Sun Oct 30, 2011  04:59PM
#      REVISION:  ---
#===============================================================================

function linux_hw_CPU {
	typeset num=0
	typeset name=""
	typeset cores=""
	name="$( cat /proc/cpuinfo | awk -F: '
/vendor_id/ { vendor=$2 }
/model name/ { model=$2 }
/cpu MHz/ {
if( model ~ "Hz" ) {speed=""} else { speed=$2? MHz" };
print vendor, model, speed; }
		' | tail -1
	)"

        num=$(if [ -r /proc/vmware/cpuinfo ]; then awk '/pcpu/ { print NF-1 }' /proc/vmware/cpuinfo; else cat /proc/cpuinfo | grep processor| wc -l; fi)

	# ESX: mas info sobre logical/cores/packages
	if [ -r /proc/vmware/sched/ncpus ]
	then
		cores=$( echo $( cat /proc/vmware/sched/ncpus ) )
	fi

	echo $num $( echo "$name ($cores)" | enclose )
}

function enclose {
	tr -s " " | sed -e "s/^/\"/; s/$/\"/; s/\"\ /\"/; s/\ \"/\"/"
}

function linux_hw_CPU {

	typeset num=0
	typeset name=""
	typeset cores=""

	name="$(
		cat /proc/cpuinfo | awk -F: '
/vendor_id/ { vendor=$2 }
/model name/ { model=$2 }
/cpu MHz/ {
if( model ~ "Hz" ) {speed=""} else { speed=$2" MHz" };
print vendor, model, speed; }
		' | tail -1
	)"

	num=$(
		if [ -r /proc/vmware/cpuinfo ]
		then
			awk '/pcpu/ { print NF-1 }' /proc/vmware/cpuinfo
		else
			cat /proc/cpuinfo | grep processor| wc -l
		fi

	)

	if grep -q "physical id" /proc/cpuinfo || grep "siblings" /proc/cpuinfo
	then
		chip_count=$( grep "physical id" /proc/cpuinfo | sort -u | wc -l )
		chip_core=$( grep "siblings" /proc/cpuinfo | tail -1 | cut -d: -f2 )
		cores="($chip_count chips x $chip_core cores)"
	fi

	# Blades HP con
	if [ -x /sbin/hpasmcli ]
	then
		chip_name=$( /sbin/hpasmcli -s "SHOW SERVER" | grep "Name" | head -1 | cut -d: -f2 )
		chip_speed=$( /sbin/hpasmcli -s "SHOW SERVER" | grep "Speed" | head -1 | cut -d: -f2 )
		chip_core=$( /sbin/hpasmcli -s "SHOW SERVER" | grep "Core" | head -1 | cut -d: -f2 )
	fi

	# ESX: mas info sobre logical/cores/packages
	if [ -r /proc/vmware/sched/ncpus ]
	then
		cores="($( echo $( cat /proc/vmware/sched/ncpus ) ))"
	fi

	# Linux Itanium IA64
	if grep -q -i itanium /proc/cpuinfo
	then
		name="$(
		grep "vendor" /proc/cpuinfo | cut -d: -f2- | tail -1 ) $(
		grep "arch " /proc/cpuinfo | cut -d: -f2- | tail -1 ) $(
		grep "family" /proc/cpuinfo | cut -d: -f2- | tail -1 ) $(
		grep "cpu MHz" /proc/cpuinfo | cut -d: -f2- | cut -d. -f1 | tail -1 ) Mhz"

		chip_count=$( grep "physical id" /proc/cpuinfo | sort -u | wc -l )
		chip_core=$( grep "siblings" /proc/cpuinfo | tail -1 | cut -d: -f2 )
		cores="($chip_count chips x $chip_core cores)"
	fi

	echo $num $( echo "$name $cores" | enclose )
}

linux_hw_CPU

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using `!#$’ to referance backward-word

Here is something that I found on the commandlinefu

cp /work/host/phone/ui/main.cpp !#$:s/host/target

Ah well…its very interesting and very useful.

Some explanation:

!# – means the current command (similar to !! being the last command)

$ – represents the last parameter

:s – is used for substitution.

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Compare files excluding certain lines.

Quick tip, you can use any expression for the sed commands in the (). With this trick you can redirect the stdout of 2 commands to the diff command. This might become very useful, if you want to compare 2 files, excluding the first  line.

diff <(sed '1d' file) <(sed '1d' file2)

More interesting example is where the string ABC is converted to abc before comparing in the second file with the following command: