71 lines
1.5 KiB
PHP
71 lines
1.5 KiB
PHP
<?php
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/**
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* Input_PO - YAGSDisasm Input block device for .PO image files
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*
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*/
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class Input_PO
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{
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// have we been initialized yet?
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private $is_initialized = false;
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// source filename
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private $source_filename;
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// number of 512-byte blocks in image
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private $total_blocks;
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// volume length in bytes
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private $total_bytes;
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// our file descriptor
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private $fp;
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public function __construct( $filename )
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{
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$fp = fopen( $filename, 'r' );
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if( !$fp )
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{
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throw new Exception( 'Input_PO: Unable to open source file '.$filename );
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}
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// source filename
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$this->source_filename = $filename;
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// bytes of disk data
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$this->total_bytes = filesize( $filename );
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// block count (little-endian)
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$this->total_blocks = $this->total_bytes / 512;
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$this->is_initialized = true;
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$this->fp = $fp;
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}
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/**
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* getBlocks( $starting_block, $num_blocks ) - Retrieve $num_blocks 512-byte blocks from the file, starting at $starting_block
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* @param $starting_block int, $num_blocks int
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* @return $data str
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*/
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public function getBlocks( $starting_block, $num_blocks )
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{
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fseek( $fp, $starting_block*512, SEEK_SET );
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$data = '';
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for( $blk=0;$blk<$num_blocks;$blk++ )
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{
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$data .= fread( $fp, 512 );
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}
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return $data;
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}
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/**
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* printInfo() - Print some information about this PO image
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*/
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public function printInfo()
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{
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echo "Source Filename: ".$this->source_filename."\n";
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echo " Image Format: ProDOS\n";
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echo " Block Count: ".$this->total_blocks."\n";
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echo " Total Bytes: ".$this->total_bytes."\n";
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}
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} |