Measure string size in Bytes in php

Question

I am doing a real estate feed for a portal and it is telling me the max length of a string should be 20 000 bytes  20kb   but I have never run across this before   How can I measure byte size of a varchar string  So I can then do a while loop to trim it down

User · Accepted Answer

You have to figure out if the string is ascii encoded or encoded with a multi-byte format.

In the former case, you can just use strlen.

In the latter case you need to find the number of bytes per character.

the strlen documentation gives an example of how to do it : http://www.php.net/manual/en/function.strlen.php#72274

User · Answer

PHP s strlen   function returns the number of ASCII characters   strlen  borsc   -  5  bytes   strlen  bor  c   -  7  bytes    limit in kBytes   20000    pointer   0  while strlen  your string   gt     pointer   1     limit in kBytes         str to handle   substr  your string    pointer    limit in kBytes     limit in kBytes          here you can handle  0 - n  parts of string      pointer        str to handle   substr  your string    pointer    limit in kBytes    limit in kBytes      here you can handle last part of string      or you can use a function like this   function parseStrToArr  string   limit in kBytes        ret   array          pointer   0      while strlen  string   gt     pointer   1     limit in kBytes             ret     substr  string    pointer    limit in kBytes     limit in kBytes            pointer                ret     substr  string    pointer    limit in kBytes    limit in kBytes        return  ret      arr   parseStrToArr  your string   limit in kBytes   20000

User · Answer

You can use mb strlen   to get the byte length using a encoding that only have byte-characters  without worring about multibyte or singlebyte strings  For example  as drake127 saids in a comment of mb strlen  you can use  8bit  encoding    lt  php      string    Ci  n ca  ones por banda       echo mb strlen  string   8bit      gt    You can have problems using strlen function since php have an option to overload strlen to actually call mb strlen  See more info about it in http   php net manual en mbstring overload php  For trim the string by byte length without split in middle of a multibyte character you can use   mb strcut string  str  int  start    int  length    string  encoding

User · Answer

Further to PhoneixS answer to get the correct length of string in bytes - Since mb strlen   is slower than strlen    for the best performance one can check  mbstring func overload  ini setting so that mb strlen   is used only when it is really required    content length   ini get  mbstring func overload     mb strlen  content    8bit     strlen  content

User · Answer

Do you mean byte size or string length   Byte size is measured with strlen    whereas string length is queried using mb strlen    You can use substr   to trim a string to X bytes  note that this will break the string if it has a multi-byte encoding - as pointed out by Darhazer in the comments  and mb substr   to trim it to X characters in the encoding of the string

[php] Measure string size in Bytes in php

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