PHP common file operation functions and example analysis

This article mainly introduces PHP common file operation functions and example analysis. Interested friends can refer to it. I hope it will be helpful to everyone.

The most commonly used file operations in PHP are reading and writing. Today we will mainly explain the reading and writing functions, and create a page access counting function to record the number of visits to a page.

fopen():There is no file creation function in PHP. The fopen() function is used to create and open files. The form of the function is: resource fopen( string filename , string mode )

The parameter filename is the name of the file that is opened or created and opened, and the parameter mode is the mode of opening. The specific mode is as follows:

fread():Can be used to read files in PHP. The form of the function is: string fread(resource handle, int length)

fread() starts from the file pointer handle Read at most length bytes, and will stop reading the file when encountering the following conditions:

When length bytes have been read,

reaches End of file (EOF)

(for network streams) when a packet is available or (after opening a userspace stream) 8192 bytes have been read

fgets():Used in PHP to read a line of data from a file and point the file pointer to the next line. The form of the function is: string fgets( resource handle, int length)

fgets() Read a line from the pointer handle and return a string with a length of at most (length-1) bytes. It will stop reading the file when it encounters the following conditions:

encounters a newline character

End of file reached (EOF)

(length-1) bytes have been read

If the length parameter is not specified, the default is 1024 bytes .

fwrite():Used in PHP to write strings to files. It returns the number of characters written when successful and false when failed. The function form is: int fwrite( resource handle , string data, int length)

fwrite() writes the contents of the string data to the file pointer handle. The parameters are as follows:

If specified Parameter length, writing will stop when length bytes have been written or the data string has been written.

Let’s take a look at an example: count the number of visits to the index.php page and write it into the count.html file. For this small matter of counting the number of page visits, we won’t bother with the database>_< , the code is as follows:

Put this code in index.php. Every time index.php is accessed, 1 will be added to count.html, then count. html, we can know the total number of visits to index.php.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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