Solved

# How do I convert an int to byte array in PHP?

Posted on 2010-08-25
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I need to convert an integer value to a 2 byte array and then to a 2 character string to write to a text file.  I obtain the value from the file using:

\$fhandle = fopen(\$this->FilePath, 'r');
echo 'My Val = '.\$myVal[1]; //let's say that \$myVal = 1234

How do I convert the value back to the original format from an integer?

Thank you,

j
0
Question by:j-tech

LVL 3

Accepted Solution

Mathias earned 500 total points
ID: 33528511
Take a look at this:

Output:
----------
0x1234
LB: 0x34
HB: 0x12
0x1234
LB: 0x34
HB: 0x12
0x12345678LW: 0x5678
HW: 0x1234
0x12345678LW: 0x5678
HW: 0x1234
Start: 0x1234
Array: 0x34, 0x12,
Array: 52, 18
String: 4
Hex output
34 12                                           | 4.
----------
``````<?php

// Function found at: http://www.theserverpages.com/scripts/

// Please leave this comment intact when using this code!

function hexoutput(\$data, \$width=16)

{

\$st=0;

\$txt="";

\$out="";

for (\$i=0; \$i<strlen(\$data); \$i++)

{

\$n=ord(substr(\$data,\$i,1));

\$out.=\$c." ";

if (\$n==32 || \$n>32 && \$n<127 || \$n>160)

{

\$txt.=substr(\$data,\$i,1);

}

else

{

\$txt.=".";

}

if (\$i % \$width == \$width-1)

{

\$out.="| ".\$txt."\n";

\$txt="";

}

}

\$out.=str_repeat("   ",\$width-(\$i % \$width));

\$out.="| ".\$txt;

\$out.="\n";

return \$out;

}

function LO_BYTE(\$x)

{

return (\$x & 0x00FF);

}

function HI_BYTE(\$x)

{

return ((\$x & 0xFF00) >> 8);

}

function LO_WORD(\$x)

{

return (\$x & 0xFFFF);

}

function HI_WORD(\$x)

{

return ((\$x >> 16) & 0xFFFF);

}

function MAKE_WORD(\$a, \$b)

{

return ((\$b << 8) + \$a);

}

function MAKE_LONG(\$a, \$b)

{

return (\$a | (\$b << 16));

}

echo '<pre>';

\$test = 0x1234;

echo sprintf("0x%04X\n", \$test);

echo sprintf("LB: 0x%02X\n", LO_BYTE(\$test));

echo sprintf("HB: 0x%02X\n", HI_BYTE(\$test));

\$test = MAKE_WORD(LO_BYTE(\$test), HI_BYTE(\$test));

echo sprintf("0x%04X\n", \$test);

echo sprintf("LB: 0x%02X\n", LO_BYTE(\$test));

echo sprintf("HB: 0x%02X\n", HI_BYTE(\$test));

\$test = 0x12345678;

echo sprintf("0x%08X", \$test);

echo sprintf("LW: 0x%04X\n", LO_WORD(\$test));

echo sprintf("HW: 0x%04X\n", HI_WORD(\$test));

\$test = MAKE_LONG(LO_WORD(\$test), HI_WORD(\$test));

echo sprintf("0x%04X", \$test);

echo sprintf("LW: 0x%04X\n", LO_WORD(\$test));

echo sprintf("HW: 0x%04X\n", HI_WORD(\$test));

\$test = 0x1234;

echo sprintf("Start: 0x%04X\n", \$test);

echo "Array: ";

\$arr = array(LO_BYTE(\$test), HI_BYTE(\$test));

foreach (\$arr as \$a)

echo sprintf("0x%02X, ", \$a);

echo "\n";

echo "Array: ".implode(", ", \$arr)."\n";

echo "String: ";

\$str = '';

foreach (\$arr as \$a)

{

\$str .= sprintf("%c", \$a);

}

echo \$str."\n";

echo "Hex output\n";

echo hexoutput(\$str);

echo '</pre>';

?>
``````
0

Author Comment

ID: 33533377
Thanks TDS, that worked perfectly.  Also helped with converting an integer to a single byte array to single character string.  Appreciate it!
0

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