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--- uphp:functions:read_unpack [2021/01/28 10:09]
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-======fread_unpack======
-<badge>WMMEGA FW >= 2.1179</badge>
-Read data from a file into an indexed array in binary form.
-====Description====
-<well size="sm"><html>
-<span style="font-size:125%;color:green">int
-<span style="color:black">fread_unpack (
-<span style="color:green">int
-<span style="color:blue">$handle<span style="color:black">,
-<span style="color:green">string
-<span style="color:blue">$format
-<span style="color:black">,
-<span style="color:green">int
-<span style="color:blue">$count<span style="color:black">
-<span style="color:black">,
-<span style="color:green">int
-<span style="color:blue">$interval<span style="color:black">
-)
-</html></well>
-This function performs a binary-safe read of data from a file into an indexed array that is automatically created.  The format parameter determines the element size of the array.
-====Parameters====
-<html><b><span style="color:blue">$handle<span style="color:black"></b></html>:  Valid handle of a previously opened file
-<html><b><span style="color:blue">$format<span style="color:black"></b>:  <b><span style="color:green">String<span style="color:black"></b> containing one of the following items:</html>
-^ Value  ^ Description                                      ^
-| l      | signed long (always 32 bit, machine byte order)  |
-| f      | floating point(always 32 bit, machine byte order)  |
-| c      | signed byte   |
-<html><b><span style="color:blue">$count<span style="color:black"></b></html>:  Number of elements to read (this will be multiplied by the array element size in byte which could be 1,2 or 4 depending on the data type)
-<html><b><span style="color:blue">$interval<span style="color:black"></b></html>:  Interval in elements to skip between reads (keep this to 1 to read a block of data)
-====Return Values====
-<html><b><span style="color:green">array<span style="color:black"></b></html> indexed array containing the data
-====Examples====
-<code php>
-<?
-  // assuming your file contains the following float:
-  // 1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10.0,11.0,12.0,13.0,14.0,15.0,16.0,17.0,18.0,19.0
-  $fh = fopen("/data.dat","r");
-  if (!$fh) {
-    print("File open failed");
-  } else {
-    $arr=fread_unpack($fh,'f',10,1);
-    // this will contain an array of 10 floating points read contiguously
-    print_r($arr);
-    // 1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10
-    $arr=fread_unpack($fh,'f',10,2);
-    // this will contain an array of 10 floating point values spaced at 2 floats apart.
-    print_r($arr);
-    // 1.0,3.0,5.0,7.0,9.0,11.0,13.0,15.0,17.0,19.0
-    fclose($fh);
-  }
-?>
-</code>
-====See Also====
-[[pack()]] - Pack data
-[[unpack()]] - Unpack data
-[[fwrite_pack()]] - Write binary data from an indexed array

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