How do I convert decimal to hexadecimal in Perl?

Question

How can I convert a number, $d = 1024, in decimal to 0xFF in hex in Perl?

The d variable needs to be assigned to a different variable and be printed, so for readability I required it to be in hexadecimal format.

Just one small hint: 1024 in hex is 0x200 while 0xFF is 255 in decimal. — , Aug 30 '13 at 06:59
For the other way around, hexadecimal to decimal, see Stack Overflow question *[How can I convert hex strings into numbers in Perl?](http://stackoverflow.com/questions/1531993)*. — Peter Mortensen, Mar 08 '16 at 00:32
1024 = 4 * 256 = 0x400 : `perl -Mbigint -E 'say 1024->as_hex'` prints 0x400 — Tinmarino, Dec 09 '18 at 21:26
For decimal to octal: *[Perl how can I print a character in octal?](https://stackoverflow.com/questions/18091384/)* (2013). The gist is using `%o` instead of `%X` with sprintf(). But isn't there a more canonical question? — Peter Mortensen, Feb 21 '23 at 07:24

score 54 · Accepted Answer · edited Aug 17 '16 at 09:23

54

1024 in decimal is not 0xFF in hex. Instead, it is 0x400.

You can use sprintf as:

my $hex = sprintf("0x%X", $d);

edited Aug 17 '16 at 09:23

Peter Mortensen

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answered May 07 '12 at 11:12

codaddict

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There is no faster way to do it (for a one liner) ? – Tinmarino Sep 02 '18 at 20:40

daxim · Answer 2 · 2013-10-14T11:48:37.130

30

Caveat: sprintf overflows at 2⁶⁴ ≅ 10¹⁹, on 32-bit even already at only 2³² ≅ 4×10⁹.

For large numbers, enable the lexical pragma bigint. as_hex is documented in Math::BigInt.

use bigint;
my $n = 2**65;
print $n->as_hex;   # '0x20000000000000000'

edited Oct 14 '13 at 11:48

answered May 07 '12 at 11:54

daxim

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score 2 · Answer 3 · edited Oct 28 '14 at 09:46

2

I put these snippets into Perl files in my $PATH:

Convert list of decimal numbers into hexadecimal and binary

for ($i = 0; $i < @ARGV; $i++) {
    printf("%d\t= 0x%x\t= 0b%b\n", $ARGV[$i], $ARGV[$i], $ARGV[$i]);
}

Convert list of hexadecimal numbers into decimal and binary

for ($i = 0; $i < @ARGV; $i++) {
    $val = hex($ARGV[$i]);
    printf("0x%x\t= %d\t= 0b%b\n", $val, $val, $val);
}

Convert list of binary numbers into decimal and hexadecimal

for ($i = 0; $i < @ARGV; $i++) {
    # The binary numbers you type must start with '0b'
    $val = oct($ARGV[$i]);
    printf("0b%b\t= %d\t= 0x%x\n", $val, $val, $val);
}

edited Oct 28 '14 at 09:46

Peter Mortensen

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answered Mar 01 '14 at 14:32

CodyChan

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It would be more idiomatic Perl if you used foreach to go through the data elements instead of the C-style for() to go through the array indices. – chicks Nov 17 '14 at 21:25
"0x%x" will output in lower case. Use "0x%X" for the correct uppercase. – Peter Mortensen Jun 16 '15 at 08:08

score 0 · Answer 4 · answered May 07 '12 at 11:13

0

You can use the classical printf().

printf("%x",$d);

answered May 07 '12 at 11:13

tuxuday

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"%x" will output in lower case. Use "%X" for the correct uppercase. – Peter Mortensen Jun 16 '15 at 08:07

How do I convert decimal to hexadecimal in Perl?

4 Answers4

I put these snippets into Perl files in my $PATH:

Convert list of decimal numbers into hexadecimal and binary

Convert list of hexadecimal numbers into decimal and binary

Convert list of binary numbers into decimal and hexadecimal

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