How to apply the selection mode of fopen() function?

How to apply the selection mode of fopen() function?

1. fopen() function

Use the fopen() function in PHP to open a file. The specific syntax format is as follows:

resource fopen ( string filename , string $mode [, int use_include_path[, resource zcontext ]] )

Parameter filename specifies the name of the file to be opened.

Note:

The parameter filename can be the file name containing the file path (for example: "C:/Windows/php.ini" or "./php.ini"), which can be used to avoid switching between different systems. To cause trouble, use "/" as the path separator, and the parameter filename can also be the URL given by the Mozhong protocol (for example: "http://mrbccd.cn" or "ftp://www.mrbccd.cn" //"), if you specify a URL address, you can open the remote file.

Parameter mode sets the method of opening the file. The parameter values ​​are as follows:

mode	Mode name	Description
r	Read only	Read mode - for reading, the file pointer is at the beginning of the file
r+	Read and write	Read and write mode —For reading and writing, the file pointer is at the beginning of the file. Writing before the end of the content of the existing file will overwrite the original
W	write-only	write mode - writing to the file, the file pointer points to the header file. If the file exists, all file contents are deleted, otherwise the function will create the file
w+	read-write	read-write mode—for reading and writing, the file pointer points to the header file. If the file exists, all file contents are deleted, otherwise the function will create the file
x	Write with caution	Open the file in write mode and start writing from the beginning of the file. If the file already exists, the file will not be opened, the function returns false, and PHP will generate a warning
x+	Write with caution	Open the file in read/write mode and start writing from the beginning of the file. If the file already exists, the file will not be opened, the function returns false, and PHP will generate a warning
a	Append	The file is opened in append mode, and the file pointer points to the tail file, if the file already has content , then appending will start from the end of the file. If the file does not exist, the function will create the file
a+	Append	Open the file in append mode, and the file pointer points to the header file. If the file already has content, then Will append or read from the end of the file. If the file does not exist, the function will create the file
b	binary	binary mode - used to connect with other modes. This may be used if the file system can differentiate between binary and text files. Windows can differentiate; UNIX does not. This option is recommended for maximum portability. It is the default mode
t	Text	for combination with other modes. This mode is just an option under Windows

The parameter use_include_path can be a selection parameter to determine whether to search for filename files in the directory defined by include_path (include_path option of php.ini). For example: set the value of the include_path option in the php.ini file to "E:AppServwwwMRInstance

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