Comments on: Linux / UNIX: Convert Hexadecimal to Decimal Number

By: sovan

sovan — Fri, 25 Nov 2011 18:09:01 +0000

how the conversion will possible when a user will give a number on his choice or from command line argument.

By: adithya kiran

adithya kiran — Wed, 23 Feb 2011 06:54:16 +0000

Hi,

You can use the following command to convert from any to any base.. for example binary to dec and dec to binary

# perl -e ‘printf “%b\n” 10′
1010
# perl -e ‘printf “%d\n” 0b1010′
10

By: Justin Anonymous

Justin Anonymous — Wed, 23 Sep 2009 18:00:48 +0000

As others have mentioned, there is so much wrong with this article. Someone needs to update it.

drpyro: what is not mentioned is once you set ibase, all numbers after are treated in that base. For your code, it should look like this:
echo "ibase=2; obase=1010; 111101101" | bc

Get it? The obase number has to be in binary (1010b = 10 decimal).

By: drpyro

drpyro — Sat, 04 Jul 2009 01:49:22 +0000

this command fail to give me the result on base 10, im i writing it the wrong way ? echo "ibase=2;obase=10;111101101" | bc when i omit obase i have the right answer exp: echo "ibase=2;111101101" | bc which is :493 I'm using bc 1.06.94

By: PK

PK — Mon, 16 Mar 2009 06:48:54 +0000

One more way I know.

from dec. to hex. conversion:
$echo ‘ibase=10; obase=16; 1237184449′ | bc
49BDEFC1

from hex. to dec. conversion: (here you specify obase in hex notation ( A=10 )
$echo ‘ibase=16; obase=A; 49BDEFC1′ | bc
1237184449

By: PK

PK — Mon, 16 Mar 2009 06:42:43 +0000

I agrre with Mockey Chen.

convert dec to hex:
$ printf “%x” 100

convert hex to dec:
$ printf “%d” 0xf4

Or simply do in bash (for hex to dec. conversion):
echo $((0×100))

By: mhymn

mhymn — Wed, 25 Feb 2009 11:31:36 +0000

aptitude install gbase && man gbase
:)

By: asdf

asdf — Sun, 15 Feb 2009 16:21:07 +0000

0xac != 99, which one should see on a first glance or at least manually check before posting.
bc defaulting to decimal for input AND output saved you in your first example.
Finally clobbering and depending on the .bashrc when there is printf on every unix is unnecessary.

By: Mockey Chen

Mockey Chen — Mon, 09 Feb 2009 02:10:20 +0000

How about just using printf, for example:
convert dec to hex:
$ printf “%x” 100

convert hex to dec:
$ printf “%d” 0xf4

simple and easy way.

By: Maqbool Patel

Maqbool Patel — Sun, 08 Feb 2009 05:17:54 +0000

Thanks, these days I am working on some byte level code reading file offsets and I was using a calculator to do this conversion. Never thought of this. Saved me lots of time. Especially the trick of adding to the .bashrc file, neat.

By: Peck

Peck — Sat, 07 Feb 2009 16:24:08 +0000

There’s an error on d2h. It’s ibase=16 to change input format to hex.
This gives the right value AC -> 172

By: tim

tim — Sat, 07 Feb 2009 13:11:09 +0000

You can also source your .bashrc file:
. ~/.bashrc

By: Vivek Gite

Vivek Gite — Sat, 07 Feb 2009 12:04:08 +0000

@Sanjeev,

You need to logout and login again so that functions get loaded.

@Loïc Pefferkorn

Thanks for sharing wcalc tool.

By: sanjeev

sanjeev — Sat, 07 Feb 2009 11:38:00 +0000

I tried this but i am not able to do this.
I edited “~/.bashrc ” file copy and pasted the above code.

By: Loïc Pefferkorn

Loïc Pefferkorn — Sat, 07 Feb 2009 11:35:28 +0000

Hello,
Thank you for the tip.
wcalc is also a handy way to do such convertions, and I found it easier to use :

To convert from hex to decimal :
$ echo “0xff”|wcalc -d
= 255

To convert from decimal to hex:
echo “255″|wcalc -h
= 0xff

Binary and octal bases are also handled., and there is a _lot_ of others options !

By: Amir Watad

Amir Watad — Sat, 07 Feb 2009 03:03:40 +0000

Hi.
A great post. Thank you for sharing.

BTW, a small correction, I think you swapped the function names h2d/d2h by mistake.

Will surely write about this in my blog. will give you the credits of course.

Thanks again.