Publish a newly compiled brute force version of the gentle version of the Chinese truncation function. It is recommended to use the brute-force version, which is safe and reliable. the gentle version is more efficient in programming. the basic principle is to correct the off and len may be misplaced. the gentle version is from the off and recommended to use the violent version, which is safe and reliable; the gentle version is more efficient from the perspective of programming. haha
The basic principle is to correct off, len may be misplaced, gentle version is from off backward lookup, find the first character <0xa0 is considered as a common character, the search is complete, determine whether there is a dislocation based on the number of times...
/**
* @ Brief simple and efficient string truncation function (supports CJK characters)
*
* It simply determines the ASCII value of the high part and can cope with the vast majority of regular Chinese and English strings.
* UTF-8 encoding of 4 or 3 bytes is not supported.
*
* Key point: modify the off value/len value of the dislocation in the double byte (pay attention to the intention that the default value of $ len is-1)
* Similar to substr (), the low position (starting from 0x40) of GBK code may be faulty.
*/
Function my_substr ($ str, $ off, $ len =-1)
{
$ Mlen = strlen ($ str );
/* Step 4: parameter security check and correction */
If ($ off <0)
$ Off = $ mlen;
If ($ off> $ mlen)
$ Off = 0;
/* Step 2: $ off correction, reverse lookup */
If ($ off> 0)
{
$ Fix = $ off;
$ Mb = false;
Do
{
$ Ch = ord ($ str {$ fix --});
If ($ ch <0x80)
Break;
$ Mb = true;
}
While ($ fix );
If ($ mb)
{
$ Fix = ($ off-$ fix );
If ($ fix & 1)
{
$ Off --;
$ Len;
}
}
}
/* Step 2: $ len correction, same as above */
If ($ len <= 0 | ($ len $ off) >=$ mlen)
{
$ Len = $ mlen-$ off;
}
Else
{
Secure and reliable. the gentle version is more efficient from the programming perspective. The basic principle is to correct off, len may be misplaced, and the gentle version is to reverse from off...
