How to delete duplicate lines in text files in php_PHP tutorial

How to delete duplicate lines in text files in php

　 How to delete duplicate lines in text files in php

This example describes how to delete duplicate lines in text files in PHP. Share it with everyone for your reference. The specific analysis is as follows:

This php function is used to delete duplicate lines in the file. You can also specify whether to ignore case and specify the newline character

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/** * RemoveDuplicatedLines * This function removes all duplicated lines of the given text file. * * @param string * @param bool * @return string */ function RemoveDuplicatedLines($Filepath, $IgnoreCase=false, $NewLine="n"){ if (!file_exists($Filepath)){ $ErrorMsg = 'RemoveDuplicatedLines error: '; $ErrorMsg .= 'The given file ' . $Filepath . ' does not exist!'; die($ErrorMsg); } $Content = file_get_contents($Filepath); $Content = RemoveDuplicatedLinesByString($Content, $IgnoreCase, $NewLine); // Is the file writeable? if (!is_writeable($Filepath)){ $ErrorMsg = 'RemoveDuplicatedLines error: '; $ErrorMsg .= 'The given file ' . $Filepath . ' is not writeable!'; die($ErrorMsg); } // Write the new file $FileResource = fopen($Filepath, 'w '); fwrite($FileResource, $Content); fclose($FileResource); } /** * RemoveDuplicatedLinesByString * This function removes all duplicated lines of the given string. * * @param string * @param bool * @return string */ function RemoveDuplicatedLinesByString($Lines, $IgnoreCase=false, $NewLine="n"){ if (is_array($Lines)) $Lines = implode($NewLine, $Lines); $Lines = explode($NewLine, $Lines); $LineArray = array(); $Duplicates = 0; // Go trough all lines of the given file for ($Line=0; $Line < count($Lines); $Line ){ // Trim whitespace for the current line $CurrentLine = trim($Lines[$Line]); // Skip empty lines if ($CurrentLine == '') continue; // Use the line contents as array key $LineKey = $CurrentLine; if ($IgnoreCase) $LineKey = strtolower($LineKey); // Check if the array key already exists, // if not add it otherwise increase the counter if (!isset($LineArray[$LineKey])) $LineArray[$LineKey] = $CurrentLine; else $Duplicates ; } // Sort the array asort($LineArray); // Return how many lines got removed return implode($NewLine, array_values($LineArray)); }

　　使用范例：

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// Example 1 // Removes all duplicated lines of the file definied in the first parameter. $RemovedLinesCount = RemoveDuplicatedLines('test.txt'); print "Removed $RemovedLinesCount duplicate lines from the test.txt file."; // Example 2 (Ignore case) // Same as above, just ignores the line case. RemoveDuplicatedLines('test.txt', true); // Example 3 (Custom new line character) // By using the 3rd parameter you can define which character // should be used as new line indicator. In this case // the example file looks like 'foo;bar;foo;foo' and will // be replaced with 'foo;bar' RemoveDuplicatedLines('test.txt', false, ';');

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// Example 1 // Removes all duplicated lines of the file definied in the first parameter. $RemovedLinesCount = RemoveDuplicatedLines('test.txt'); print "Removed $RemovedLinesCount duplicate lines from the test.txt file."; // Example 2 (Ignore case) // Same as above, just ignores the line case. RemoveDuplicatedLines('test.txt', true); // Example 3 (Custom new line character) // By using the 3rd parameter you can define which character // should be used as new line indicator. In this case // the example file looks like 'foo;bar;foo;foo' and will // be replaced with 'foo;bar' RemoveDuplicatedLines('test.txt', false, ';'); 　　希望本文所述对大家的php程序设计有所帮助。 http://www.bkjia.com/PHPjc/991652.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/991652.htmlTechArticlephp删除文本文件中重复行的方法 php删除文本文件中重复行的方法 本文实例讲述了php删除文本文件中重复行的方法。分享给大家供大家参考...