Use php to implement PHP script engine built-in functions again

// It's really boring. It's a strange idea. I want to re-use PHP to implement some encapsulated functions in PHP,
// The following code mainly implements some string processing functions in PHP, and implements some PHP
// None, but the same function of string processing functions can also be implemented in other languages.
// Now, such as using C/VBScript/Perl, you can have your own function library.
// The following functions may not be able to run successfully, just for learning.
//
// If there is no special declaration, it is all because heiyeluren is original. To use any function, keep the author information.

/**
* String Functions Reconstruct
*
* Copyright (c) 2005 heiyeluren * Author: heiyeluren

* $ Id: StringFunctions. php, v 0.1 e 2005-5-29 heiyeluren Exp $
**/

// {Strlen ()
/**
* Count string length
*
* @ Param string $ str need count length string variable
* @ Return int return count result
* @ Version v0.1
* @ Create 2005-5-24
* @ Modified 2005-5-24
* @ Author heiyeluren */
Function strlen1 ($ str)
{
If ($ str = '')
Return 0;

$ Count = 0;
While (1)
{
If ($ str [$ count]! = NULL)
{
$ Count ++;
Continue;
}
Else
Break;
}
Return $ count;
}
//}}}

// {Substr ()
/**
* Get sub string
*
* @ Param string $ str need get sub string variable
* @ Param int $ start get sub string
* @ Param int $ length need get string length
* @ Return string return sub string
* @ Version v0.2
* @ Create 2005-5-24
* @ Modified 2005-5-25
* @ Author heiyeluren */
Function substr1 ($ str, $ start, $ length = 0)
{
If ($ str = '')
Return;
If ($ start> strlen ($ str ))
Return;
If ($ length! = NULL) & ($ start> 0) & ($ length> strlen ($ str)-$ start ))
Return;
If ($ length! = NULL) & ($ start <0) & ($ length> strlen ($ str) + $ start ))
Return;

If ($ length = NULL)
$ Length = (strlen ($ str)-$ start );

If ($ start <0)
{
For ($ I = (strlen ($ str) + $ start); $ I <(strlen ($ str) + $ start + $ length); $ I ++)
{
$ Substr. = $ str [$ I];
}
}

If ($ length> 0)
{
For ($ I = $ start; $ I <($ start + $ length); $ I ++)
{
$ Substr. = $ str [$ I];
}
}

If ($ length <0)
{
For ($ I = $ start; $ I <(strlen ($ str) + $ length); $ I ++)
{
$ Substr. = $ str [$ I];
}
}
Return $ substr;
}
//}}}

// {Strrev ()
/**
* Reversal string order
*
* @ Param string $ str need reversal string variable
* @ Return string reversal string
* @ Version v0.1
* @ Create 2005-5-24
* @ Modified 2005-5-24
* @ Author heiyeluren */
Function strrev1 ($ str)
{
If ($ str = '')
Return 0;
For ($ I = (strlen ($ str)-1); $ I> = 0; $ I --)
{
$ Rev_str. = $ str [$ I];
}
Return $ rev_str;
}
//}}}

// {Strcmp ()
/**
* String comparison
*
* @ Param string $ s1 first string
* @ Param string $ s2 second string
* @ Return int return-1, str1 <str2; return 1, str1> str2, str1 = str2,
* Return 0, other, return false
* @ Version v0.1
* @ Create 2005-5-24
* @ Modified 2005-5-24
* @ Author heiyeluren */
Function strcmp1 ($ s1, $ s2)
{
If (strlen ($ s1) <strlen ($ s2 ))
Return-1;
If (strlen ($ s1)> strlen ($ s2 ))
Return 1;

For ($ I = 0; $ I <strlen ($ s1); $ I ++)
{
If ($ s1 [$ I] ==$ s2 [$ I])
Continue;
Else
Return false;
}
Return 0;
}
//}}}

// {Strchr (), strstr (), strpos ()
/**
* Find first occurrence of a string
*
* @ Param string $ str parent string
* @ Param string $ substr need match sub string
* @ Return int return find sub string at parent string first place,
* F not find, return false
* @ Version v0.4
* @ Create 2005-5-24
* @ Modified 2005-5-29
* @ Author heiyeluren */
Function strchr1 ($ str, $ substr)
{
$ M = strlen ($ str );
$ N = strlen ($ substr );

If ($ m <$ n)
Return false;

For ($ I = 0; $ I <= ($ m-$ n + 1); $ I ++)
{
$ Sub = substr ($ str, $ I, $ n );
If (strcmp ($ sub, $ substr) = 0)
Return $ I;
}
Return false;
}
//}}}

// {Str_replace ()
/**
* Replace all occurrences of the search string with the replacement string
*
* @ Param string $ substr need replace sub string variable
* @ Param string $ newsubstr new sub string
* @ Param string $ str operate parent string
* @ Return string return replace after new parent string
* @ Version v0.2
* @ Create 2005-5-24
* @ Modified 2005-5-29
* @ Author heiyeluren */
Function str_replace1 ($ substr, $ newsubstr, $ str)
{
$ M = strlen ($ str );
$ N = strlen ($ substr );
$ X = strlen ($ newsubstr );

If (strchr ($ str, $ substr) = false)
Return false;

For ($ I = 0; $ I <= ($ m-$ n + 1); $ I ++)
{
$ I = strchr ($ str, $ substr );
$ Str = str_delete ($ str, $ I, $ n );
$ Str = str_insert ($ str, $ I, $ newstr );
}
Return $ str;
}
//}}}

/************ The following string processing functions are not found in PHP, play ***************/

// {Insert_str (), delete_str (), index_str ()
/**
* Basic string operate
*
* @ Param string $ str need get sub string variable
* @ Param int $ start get sub string
* @ Param int $ length need get string length
* @ Return string return sub string
* @ Version v0.1
* @ Create 2005-5-24
* @ Modified 2005-5-24
* @ Author heiyeluren */
Function str_insert ($ str, $ I, $ substr)
{

For ($ j = 0; $ j <$ I; $ j ++)
{
$ Startstr. = $ str [$ j];
}

For ($ j = $ I; $ j <strlen ($ str); $ j ++)
{
$ Laststr. = $ str [$ j];
}
$ Str = ($ startstr. $ substr. $ laststr );

Return $ str;
}

Function str_delete ($ str, $ I, $ j)
{
For ($ c = 0; $ c <$ I; $ c ++)
{
$ Startstr. = $ str [$ c];
}

For ($ c = ($ I + $ j); $ c <strlen ($ str); $ c ++)
{
$ Laststr. = $ str [$ c];
}

$ Str = ($ startstr. $ laststr );

Return $ str;
}
//}}}

// {Strcpy ()
/**
* Use designate sub string replace string
*
* @ Param string $ str need get sub string variable
* @ Param int $ start get sub string
* @ Param int $ length need get string length
* @ Return string return sub string
* @ Version v0.1
* @ Create 2005-5-27
* @ Modified 2005-5-27
* @ Author heiyeluren */
Function strcpy ($ s1, $ s2)
{
If (strlen ($ s1) = NULL)
Return;
If (! Isset ($ s2 ))
Return;

For ($ I = 0; $ I <strlen ($ s1); $ I ++)
{
$ S2 [] = $ s1 [$ I];
}
Return $ s2;
}
//}}}

// {Strcat ()
/**
* Use designate sub string replace string
*
* @ Param string $ str need get sub string variable
* @ Param int $ start get sub string
* @ Param int $ length need get string length
* @ Return string return sub string
* @ Version v0.1
* @ Create 2005-5-27
* @ Modified 2005-5-27
* @ Author heiyeluren */
Function strcat ($ s1, $ s2)
{
If (! Isset ($ s1 ))
Return;
If (! Isset ($ s2 ))
Return;

$ Newstr = $ s1. $ s2;

Return $ newsstr;
}
//}}}

// {Php_encode (), php_decode ()
/**
* Simple string encode/decode function
*
* @ Param string $ str need code/encode string variable
* @ Return string code/encode after string
* @ Version v0.2
* @ Create 2005-3-11
* @ Modified 2005-5-24
* @ Author heiyeluren */

/* String encode function */
Function php_encode ($ str)
{
If ($ str = ''& strlen ($ str)> 128)
Return false;

For ($ I = 0; $ I <strlen ($ str); $ I ++)
{
$ C = ord ($ str [$ I]);
If ($ c> 31 & $ c <107)
$ C + = 20;
If ($ c> 106 & $ c <127)
$ C-= 75;
$ Word = chr ($ c );

$ S. = $ word;
}
Return $ s;
}

/* String decode function */
Function php_decode ($ str)
{
If ($ str = ''& strlen ($ str)> 128)
Return false;

For ($ I = 0; $ I <strlen ($ str); $ I ++)
{
$ C = ord ($ word );
If ($ c> 106 & $ c <127)
$ C = $ c-20;
If ($ c> 31 & $ c <107)
$ C = $ c + 75;
$ Word = chr ($ c );

$ S. = $ word;
}
Return $ s;
}
//}}}

// {Php_encrypt (), php_decrypt ()
/**
* Simple string encrypt/decrypt function
*
* @ Param string $ str need crypt string variable
* @ Return string encrypt/decrypt after string
* @ Version v0.1
* @ Create 2005-5-27
* @ Modified 2005-5-29
* @ Author heiyeluren */

/* Define crypt key */
$ Encrypt_key = 'abcdefghijklmnopqrstuvwxyz1234567890 ';
$ Decrypt_key = 'ngzqtcobmuhelkpdawxfyivrsj2468038559 ';

/* String encrypt function */
Function php_encrypt ($ str)
{
Global $ encrypt_key, $ decrypt_key;

If (strlen ($ str) = 0)
Return false;

For ($ I = 0; $ I <strlen ($ str); $ I ++)
{
For ($ j = 0; $ j <strlen ($ encrypt_key); $ j ++)
{
If ($ str [$ I] ==$ encrypt_key [$ j])
{
$ Enstr. = $ decrypt_key [$ j];
Break;
}
}
}
Return $ enstr;
}

/* String decrypt function */
Function php_decrypt ($ str)
{
Global $ encrypt_key, $ decrypt_key;

If (strlen ($ str) = 0)
Return false;

For ($ I = 0; $ I <strlen ($ str); $ I ++)
{
For ($ j = 0; $ j <strlen ($ decrypt_key); $ j ++)
{
If ($ str [$ I] ==$ decrypt_key [$ j])
{
$ Enstr. = $ encrypt_key [$ j];
Break;
}
}
}
Return $ enstr;
}
//}}}

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