Explanation of file operation examples in PHP

This article mainly shares with you the explanation of file operation examples in PHP. file_put_contents (file address, content [,FILE_APPEND]); FILE_APPEND means append writing. Without the third parameter, the content in the original file will be cleared before writing.

file_get_content (file address); Read the content in the file.

The above two functions are both read and write operations on files, but they can only read the contents of the entire file at once. When the file is too large, this function is not applicable. At this time, the following series of functions can be used to operate the file.

# FOPEN (file address, open method);

# PHP method: R (read) read only the mode.

w (write) writing mode. Empty the contents of the file and then write it (automatically create a file that does not exist).

Replace x with The same as w, but the file cannot be created automatically and an error will be reported when the file does not exist.

a (append) append. Add input at the end of the original file. (That is, the file pointer is at the end after opening the file)

                                                                                                                                                                                                                                                                              . After opening the file, the file pointer is placed at the beginning. Unlike r, it can also perform writing operations at the pointer position.

                                                                                                                                                                                                                                   Zero out the contents of the file and place the pointer at the beginning of the file. Both read and write operations are possible.

a+ Append read and write mode. Writing is always at the end of the file, and the speed is limited by the pointer position.

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fread(file handle[,length] ); Read the content of the specified length (in bytes, up to 8192 bytes).

                                                                                                                                                                          fgets (file handle, length); reads a string of specified length (actual read length = specified length - 1). In addition to the length, the end of the line is also the termination read operation of this function. Depends on which condition is met first. Generally used to read a row of data.

                                                                                                                                                    fgetc (file handle); reads one byte at a time.

Note: The three reading functions all operate on the pointer, and the pointer will be moved during the reading process.

FWRITE (file handle, write content); write the content at the specified location, usually instructed by the file pointer.

                                                                                                                                                                      fclose (file handle); close the file.

Functions that operate pointers:

ftell (file handle): Get the position of the pointer.

                                                                                                                                                          fseek (file handle, number of bytes): sets the position of the pointer.

Other functions:

filemtime (file address); the time when the file was last modified.

filesize (file address); file size (bytes).

related suggestion:

Sharing of PHP file operation examples

Summary of PHP file operation methods

Detailed introduction to PHP file operations

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