The pack Function Character Codes : pack « System Functions « Perl

1. Perl
2. System Functions
3. pack

The pack Function Character Codes

     


Character Code           Meaning

a                        Convert to its ASCII character value; pad empty characters with null

A                        Convert to its ASCII character value; pad empty characters with spaces

b                        Convert to a bit string from low to high order bit

B                        Convert to a bit string from high to low order bit

c                        Convert to a signed character

C                        Convert to an unsigned character

d                        Convert to a double-precision (floating-point number in the native platform format)

f                        Convert to a single-precision (floating-point number in the native platform format)

h                        Convert a hex string, putting the lower order nibble first

H                        Convert a hex string to ASCII characters, putting the high order nibble first

i                        Convert to signed integer format

I                        Convert to unsigned integer format

l                        Convert to signed long format

L                        Convert to unsigned long format

n                        Convert to short big endian order

N                        Convert to long big endian order

p                        Convert a pointer to string format

P                        Convert a pointer to a fixed-length string

s                        Convert to signed short format

S                        Convert to unsigned short format

v                        Convert to short little endian format

V                        Convert to long little endian format

u                        Convert to uu encoded format

x                        Insert null byte

X                        Back up one byte

@                        Null fill to absolute position




#!/usr/local/bin/perl

$packed = pack "a10" , "Test";

print "$packed Null Padded\n\n";

print "pad empty characters with spaces\n\n";

$packed = pack "A10" , "Test";

print "$packed Space Padded\n\n";

$packed = pack "b32" , "01000101010100100100100101000011";

print "$packed The right most bit is the most significant\n\n";

$packed = pack "B32" , "01000101010100100100100101000011";

print "$packed The left most bit is the most significant\n\n";

$packed = pack "c4", 0x45, 0x52, 0x49, 0x43;

print "$packed Numbers (hex) to ASCII, unsigned\n\n";

$packed = pack "C4", , 101, 114, 105, 99;

print "$packed Numbers (decimal) to ASCII, signed\n\n";

$packed = pack "h8", "11111111111";

print "$packed Hex low Nibble first to  ASCII\n\n";

$packed = pack "H8", "1111111111";

print "$packed Hex High Nibble first to ASCII\n\n";

$packed = pack "d", , 101.134;

print "$packed Double Precision native format packed for shipment\n\n";

$packed = pack "f", , 101.134;

print "$packed Single Precision native format packed for shipment\n\n";

$packed = pack "i5", , "97","98","99","100","101";

print "$packed Unsigned Packed Integers\n\n";

$packed = pack "I5", , "97","98","99","100","101";

   
    
    
    
    
  

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