fgets() and fread() - What is the difference?

不问归期 提交于 2019-12-02 21:53:20
Pascal MARTIN

fgets reads a line -- i.e. it will stop at a newline.

fread reads raw data -- it will stop after a specified (or default) number of bytes, independently of any newline that might or might not be present.


Speed is not a reason to use one over the other, as those two functions just don't do the same thing :

  • If you want to read a line, from a text file, then use fgets
  • If you want to read some data (not necessarily a line) from a file, then use fread.

fread() for binary data and fread has a limit on how many chars you can read

$source_file = fopen( $filename, "r" ) or die("Couldn't open $filename");
while (!feof($source_file)) {
    $buffer = fread($source_file, 5);  
   var_dump($buffer); //return string with length 5 chars!
}

Number 5 is length bytes have been read .

The function fgets reads a single line from a text file. It is reading so long until the end of the current line (or the end of the file) is reached. Therefore, if you would like to read one line from a text file, you should use fgets. The function fread not only reads until the end of the line but to the end of the file [e.g. fread($handle)] or as many bytes as specified as a parameter [e.g. fread($handle, 1024)]. So, if you would like to read a complete file, no matter whether it is a text file with all containing lines or arbitrary raw data from a file, you should use fread.

易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!