欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  后端开发

php删除文本文件中重复行的方法_PHP教程

程序员文章站 2024-02-01 14:28:58
...

php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。具体分析如下:

  这个php函数用来删除文件中的重复行,还可以指定是否忽略大小写,和指定换行符

  ?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

/**

* 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

// 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:

  ?

1

2

3

4

5

6

7

8

9

10

11

12

13

// 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。

www.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...
相关标签: php 文本 文件

上一篇: Vue入门

下一篇: