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A simple bash shell hex converter UNIX
If you have a value in hex format and want to see its decimal value, you can easily convert it using the terminal. To convert 3f hexadecimal type (in a bash shell):
 $ let x=0x3f
 $ echo $x

 $ let x=0xfffe
 $ echo $x
[robg adds: Not much call for hex converters in my line of work, but I thought some of you might find this useful...]
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A simple bash shell hex converter | 12 comments | Create New Account
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Call bash non-interactively
Authored by: adashiel on Mar 04, '03 10:58:55AM

If you're using tcsh, rather than spawning a bash subshell for this, you can invoke bash non-interactively with a "bash -c '<command>'". Thus:

% bash -c 'let x=0x3F ; echo $x'

[ Reply to This | # ]
Try bc(1) too
Authored by: mkhaw on Mar 04, '03 11:46:48AM

bc is also able to do radix conversions in just about any radix (expressible in numerals and uppercase letters). For example, for hex to decimal...

tcsh% bc

Or, for a shell 1-liner...

tcsh% echo "ibase=16; 3F" | bc
Defining a csh alias or sh function named hex2dec is left as an exercise for the reader :^)!

Note (1) you have to use uppercase, (2) once you specify a non-decimal input base (via ibase=...) ALL your input is in the new radix until you change it.

bc is pretty powerful, capable of arbitrary precision math, function definition, complex C-like flow control expressions, etc. See the man page for details.

[ Reply to This | # ]
Don't forget obase
Authored by: wfolta on Mar 04, '03 12:34:14PM
You can convert from, say, octal to hex by:


Note that obase is first since ibase changes your input base for all following commands, including the obase command if you reversed the order.

[ Reply to This | # ]

A simple bash shell hex converter
Authored by: cynikal on Mar 04, '03 02:47:11PM

isntead of two commands, you can do it using arithmetic expression interpolation:

echo $[0xfffe]

same thing..

[ Reply to This | # ]
Authored by: martinx on Mar 04, '03 05:58:46PM

printf is a bit more flexible, you can convert from hex back into decimal,
etc. It works just about like the C library function, only you run it from
the shell.

$ printf "%02X\n", 123
$ printf "%d\n", 0x7B

[ Reply to This | # ]
A simple bash shell hex converter
Authored by: opeer on Mar 04, '03 07:33:46PM

Well, being from a linux environment, two possibly easier methods come to mind:

1) Use the command 'man ascii' shows a complete ascii table w/ conversion
from ASCII to Octal, Hex, and Integer.

2) A utility built-in to OS X is 'hexdump'. Type this at any terminal, then insert your character. Then type '^D' aka cntrl-D twice. Result shows a fake memory address and then the hex value(the first two are the ascii representation of the hex. Also for more options use 'man hexdump'

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Perl version
Authored by: hayne on Mar 04, '03 09:57:58PM
Here's how you could do it as a Perl one-liner:
perl -e 'print 0x3f, "\n"'


perl -e 'printf("%d\n", 0x3f)'

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backslashes (sigh)
Authored by: hayne on Mar 04, '03 10:01:59PM

The last "n" in both version is supposed to be "\\n" - i.e. backslash-n.

It seems the Geeklog bug with backslashes is not yet fixed - sigh.

[ Reply to This | # ]
A simple bash shell hex converter
Authored by: tfiedler on Mar 04, '03 10:32:37PM

Two bash aliases that might help out...

alias h2d='printf "%d\n" ${1}'
alias d2h='printf "0x%x\n" ${1}'

You can then just type "h2d 0xff" or "d2h 15" and get what you are looking for.

[ Reply to This | # ]
A simple bash shell hex converter
Authored by: mervTormel on Mar 04, '03 11:42:42PM

now, when did bash start allowing command line args in aliases?

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And in Python
Authored by: sreeves on Mar 05, '03 10:10:30AM
Python is included with 10.2:

% python -c "print 0x3f"
% python -c "print hex(123)"

[ Reply to This | # ]
A simple bash shell hex converter
Authored by: Kibe on Sep 01, '03 04:00:02PM

Well, i just found a way that is simple enough to actually remember. Type in "bc" w/o the quotes, then return in the default shell(i dont know about ne others) then change the variables "ibase" and "obase" to suit ur input and output respectivly. I.e:

[------:~] --------% bc
bc 1.05
Copyright 1991, 1992, 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
obase = 16

that is how i converted 300 into hex, to go back i wud now type this:
ibase = 16
obase = 10

this works for any numbering system. input limits are base 2-16, output is 2-999.
so if im feeling insane i can convert base 2(binary) into base 600.
type in "man bc" for more info including how base systems higher than 16 are displayed(11-16 use lettering like hex, base 16)

this is the easiest way by far to both use and remember, not to mention actually type corectly.

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