Home Backend Development PHP Tutorial 效率较高的php下读取文本文件的代码[原创]_php技巧

效率较高的php下读取文本文件的代码[原创]_php技巧

May 17, 2016 am 09:36 AM
php text file

 fread :以字节位计算长度,按照指定的长度和次数读取数据,遇到结尾或完成指定长度读取后停止. 
fgets :整行读取,遇到回车换行或结尾停止.在文本方式时使用.
读字符串函数fgets函数的功能是从指定的文件中读一个字符串到字符数组中,
函数调用的形式为:
fgets(字符数组名,n,文件指针);
其中的n是一个正整数。
表示从文件中读出的字符串不超过 n-1个字符。
在读入的最后一个字符后加上串结束标志'\0'。
例如:fgets(str,n,fp);的意义是从fp所指的文件中读出n-1个字符送入字符数组str中。
按行读取)fgets()每次读入一行就会指向下一行.
所以把前面10行读进去了就清除. 
然后下一次fgets()就是第十一行了. 

fgets()怎么每次都是读一行?你怎么设定?
fread是用于整块数据的读写函数,可用来读写一组数据,如一个数组元素,一个结构变量的值等。
读数据块函数调用的一般形式为: 
fread(buffer,size,count,fp),其中buffer是一个指针,
在fread函数中,它表示存放输入数据的首地址。
size 表示数据块的字节数。
count 表示要读写的数据块块数。
fp 表示文件指针。 
例如: fread(fa,4,5,fp); 其意义是从fp所指的文件中,每次读4

fread -- 读取文件(可安全用于二进制文件)
在区分二进制文件和文本文件的系统上(如 Windows)打开文件时,
fopen() 函数的 mode 参数要加上 'b'。
$handle = fopen($filename, "rb"); 
本人使用的方法,如果你有好的方法,大家分享下啊

复制代码 代码如下:

$handle = @fopen($path, "r"); 
    if ($handle) {     
$buffer = fread($handle, 400); 
echo $buffer; 
fclose($handle); 

?>
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