Detailed explanation based on PHP file operations_PHP tutorial

Copy code The code is as follows:

$path1= "E:/myphp/text.txt";
if (!file_exists($path1)){
echo "The file does not exist!";
}else{
$handle1 = fopen($path1, 'r+') or exit("Unable to open file" );
// while (!feof($handle1)){
// echo fgets($handle1)."
";
// }
while(!feof( $handle1)){
echo fgetc($handle1);
}
}

The above code illustrates a simple file reading operation. Explanation:
fopen is to open file resources.
Usage:
$file=fopen("welcome.txt","r");
Specific meaning: The first parameter is the file path. The following parameters are required to use the method to open the file. There are several types:
r Read-only. Start at the beginning of the file.
r+ Read/write. Start at the beginning of the file.
w Write only. Opens and clears the contents of the file; if the file does not exist, creates a new file.
w+ Read/write. Opens and clears the contents of the file; if the file does not exist, creates a new file.
a Append. Opens and writes to the end of a file, or creates a new file if it does not exist.
a+ Read/Append. Maintain file contents by writing to the end of the file.
x Write only. Create new file. Returns FALSE if the file already exists.
x+
Read/write. Create new file. If the file already exists, returns FALSE and an error.

Note: If fopen() cannot open the specified file, it returns 0 (false).
The first 4 are more commonly used.
fgetc:
string fgetc ( resource$handle )
Returns a string containing one character obtained from the file pointed to by handle. Returns FALSE if EOF is encountered.

fgets:
string fgets (int$handle [,int$length])
Read a line from the file pointed to by handle and return a line with a length of at most length - 1 byte string. Stops when a newline character (included in the return value), EOF, or length - 1 bytes has been read (whichever occurs first). If length is not specified, it defaults to 1K, or 1024 bytes.
Returns FALSE on error.

fgetss:
string fgetss ( resource$handle [,int$length [,string$allowable_tags ]] )
Same as fgets(), except that fgetss attempts to read from Remove any HTML and PHP tags from the text. (Same as fgets(), except that it filters html and php tags.)
You can use the optional third parameter to specify which tags are not to be removed.
The feof() function detects whether the end of file (eof) has been reached.

//Judge whether the file or directory exists
bool file_exists(string filename)
Judge whether the file or directory exists, return true if it exists, otherwise return false
Format:

Copy code The code is as follows:

if(file_exists("hello.txt"))
{
Echo “File exists”;
}
//Open file

Format:
fopen(filename,mode)
Description: Open the specified file in the specified format
filename: The file name to be opened
mode: Open mode
fopen("hello.txt","w");
means opening the hello.txt file in writing mode

//Write file
Format:
fwrite(resource,string);
Description: Add the specified content to the open file
resource: open file
string: Content to be written
Example:
$handle = fopen("hello.txt","w") //If a, data can be appended
fwrite($handle,”1rn”)

//Close the file
Format:
fclose($handle)
Description: Close the open file
Example:
$handle = fopen(“hello .txt”,”w”);
fclose($handle);

//Read a line of data
Format:
fgets(int handle[,int length])
Description: Read length-1 characters. If length is not specified, the default byte is 1KB.
If a newline, EOF or length-1 characters have been read, the program will terminate.
Return false when an error occurs;
Example:
$handle = fopen(“hello.txt”,”r”);
$buffer = fgets($handle,1024);
echo $handle; //Output a line Information

//Read the entire file
Format:
readfile(filename)
Description: Read the entire file and output it to the browser
Example:

readfile(“hello.txt”);
?>

//Get the file size
Format:
filesize(filename)
Description: Get the specified file size, return false on error
Example:
filesize(“a.rar”)

//Delete file
Format:
unlink()
Description: Delete a file, return true if successful, otherwise return false
Example:
unlink ("b.txt")

//Create a directory
Format:
mkdir(dirname)
Description: Create a directory
Example: mkdir("newfolder"); //In the current directory Create new folder

//Delete directory
Format:
rmdir(dirname)
Description: Delete a directory
Example: rmdir("newfolder");

//Get the file name
Format:
basename(filepath)
Description: Return the file name from the specified path
Example:
basename(" c:mytoolsa.txt”) //return a.txt

//Get the file path information
pathinfo(path)
Description: Return the file path information, the result is saved in the array, the array subscript is
dirname (path), basename (file name), extension (extension name)
Example: pathinfo(“c:mytoolsa.txt”)

//Get the absolute path
Format:
realpath(filename)
Description: Get the absolute path of the specified file, return false on failure
Example: realpath(" h.txt”) //F:apacheexampleh.txt

//Copy file
Format:
copy(source,dest)
Instructions: Copy the source file to dest
Example: copy(“h.txt ","newflodera.txt")

//Determine whether it is a directory
Format:
is_dir(filename)
Description: Determine whether the given file name is a directory. If filename exists and
is a directory, return true, otherwise return false. As follows:

if(is_dir(“newfolder”)){

echo “is the file directory”; }

//Open directory

Format: opendir(path)
Description: Open a specified file directory and return a resource identifier

Example:

$hand = opendir (".") //Open the root directory

//Read directory
Format:
readdir($handle)Description: Read an open file directory stream
readdir($hand);

//Close the directory
Format: closedir($handle)
Description: Close an open directory stream
Example: closedir($hand);

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TechArticleCopy the code as follows: $path1= "E:/myphp/text.txt"; if(!file_exists( $path1)){ echo "The file does not exist!"; }else{ $handle1 = fopen($path1, 'r+') or exit("Unable to open file"); /...