php 한글 메뉴얼 도움말 검색 사이트 Binary-safe file read [function.fread]

설명

string fread ( resource $handle , int $length )

fread() reads up to length bytes from the file pointer referenced by handle. Reading stops as soon as one of the following conditions is met:

length bytes have been read
EOF (end of file) is reached
a packet becomes available or the socket timeout occurs (for network streams)
if the stream is read buffered and it does not represent a plain file, at most one read of up to a number of bytes equal to the chunk size (usually 8192) is made; depending on the previously buffered data, the size of the returned data may be larger than the chunk size.

인수

handle: 일반적으로 fopen()으로 생성하는 파일 시스템 포인터 resource.
length: Up to length number of bytes read.

반환값

Returns the read string 실패 시 FALSE를 반환합니다.

예제

Example #1 A simple fread() example


<?php
// get contents of a file into a string
$filename = "/usr/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>

Example #2 Binary fread() example

Warning

On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen() mode parameter.


<?php
$filename = "c:\\files\\somepic.gif";
$handle = fopen($filename, "rb");
$contents = fread($handle, filesize($filename));
fclose($handle);
?>

Example #3 Remote fread() examples

Warning

When reading from anything that is not a regular local file, such as streams returned when reading remote files or from popen() and fsockopen(), reading will stop after a packet is available. This means that you should collect the data together in chunks as shown in the examples below.


<?php
// For PHP 5 and up
$handle = fopen("http://www.example.com/", "rb");
$contents = stream_get_contents($handle);
fclose($handle);
?>


<?php
$handle = fopen("http://www.example.com/", "rb");
if (FALSE === $handle) {
    exit("Failed to open stream to URL");
}

$contents = '';

while (!feof($handle)) {
    $contents .= fread($handle, 8192);
}
fclose($handle);
?>

주의

Note:
If you just want to get the contents of a file into a string, use file_get_contents() as it has much better performance than the code above.

Note:
Note that fread() reads from the current position of the file pointer. Use ftell() to find the current position of the pointer and rewind() to rewind the pointer position.

참고

fwrite() - Binary-safe file write
fopen() - Opens file or URL
fsockopen() - Open Internet or Unix domain socket connection
popen() - Opens process file pointer
fgets() - Gets line from file pointer
fgetss() - Gets line from file pointer and strip HTML tags
fscanf() - Parses input from a file according to a format
file() - Reads entire file into an array
fpassthru() - Output all remaining data on a file pointer
ftell() - Returns the current position of the file read/write pointer
rewind() - Rewind the position of a file pointer