For C/C++ programmers.
fscanf() does not work like C/C++, because PHP's fscanf() move file pointer the next line implicitly.
fscanf
(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
fscanf — フォーマットに基づきファイルからの入力を処理する
説明
関数fscanf() は sscanf()
に似ていますが、stream が指すファイルから入力を取得し、
指定したフォーマット format に基づき解釈を行います。
フォーマット文字列におけるあらゆる空白は
入力ストリームのあらゆる空白にマッチします。
これはつまりフォーマット文字列のタブ (\t) すらも
入力ストリームの空白1個にマッチしてしまうことを意味します。
fscanf() をコールするたびに、ファイルから 1 行ずつ読み込みます。
パラメータ
戻り値
この関数のパラメータが二つだけの場合、処理された値は配列として返されます。 他方、オプションのパラメータが指定された場合、 この関数は、代入された値の数を返します。 オプション引数は参照渡しとする必要があります。
string で利用可能な部分文字列よりも、
format で期待された部分文字列の数が多い場合は、null が返されます。
その他のエラーが発生した場合は、false が返されます。
例
例1 fscanf() の例
<?php
$handle = fopen("users.txt", "r");
while ($userinfo = fscanf($handle, "%s\t%s\t%s\n")) {
list ($name, $profession, $countrycode) = $userinfo;
//... これらの値を使用して何か行う
}
fclose($handle);
?>
例2 users.txt の内容
javier argonaut pe hiroshi sculptor jp robert slacker us luigi florist it
add a note
User Contributed Notes 10 notes
yasuo_ohgaki at hotmail dot com ¶
23 years ago
Bertrand dot Lecun at prism dot uvsq dot Fr ¶
17 years ago
It would be great to precise in the fscanf documentation
that one call to the function, reads a complete line.
and not just the number of values defined in the format.
If a text file contains 2 lines each containing 4 integer values,
reading the file with 8 fscanf($fd,"%d",$v) doesnt run !
You have to make 2
fscanf($fd,"%d %d %d %d",$v1,$v2,$v3,$v4);
Then 1 fscanf per line.
eugene at pro-access dot com ¶
22 years ago
If you want to read text files in csv format or the like(no matter what character the fields are separated with), you should use fgetcsv() instead. When a text for a field is blank, fscanf() may skip it and fill it with the next text, whereas fgetcsv() correctly regards it as a blank field.
worldwideroach at hotmail dot com ¶
19 years ago
Yet another function to read a file and return a record/string by a delimiter. It is very much like fgets() with the delimiter being an additional parameter. Works great across multiple lines.
function fgetd(&$rFile, $sDelim, $iBuffer=1024) {
$sRecord = '';
while(!feof($rFile)) {
$iPos = strpos($sRecord, $sDelim);
if ($iPos === false) {
$sRecord .= fread($rFile, $iBuffer);
} else {
fseek($rFile, 0-strlen($sRecord)+$iPos+strlen($sDelim), SEEK_CUR);
return substr($sRecord, 0, $iPos);
}
}
return false;
}
nico at nicoswd dot com ¶
11 years ago
If you want to parse a cron file, you may use this pattern:
<?php
while ($cron = fscanf($fp, "%s %s %s %s %s %[^\n]s"))
{
}
?>
loco.xxx at gmail dot com ¶
18 years ago
to include all type of visible chars you should try:
<?php fscanf($file_handler,"%[ -~]"); ?>
robert at NOSPAM dot NOSPAM ¶
22 years ago
actually, instead of trying to think of every character that might be in your file, excluding the delimiter would be much easier.
for example, if your delimiter was a comma use:
%[^,]
instead of:
%[a-zA-Z0-9.| ... ]
Just make sure to use %[^,\n] on your last entry so you don't include the newline.
arentzen at religion dot dk ¶
17 years ago
If you want fscanf()to scan one variable in a large number of lines, e.g an Ipadress in a line with more variables, then use fscanf with explode()
<?
$filename = "somefile.txt";
$fp = fopen($filename, "r") or die ("Error opening file! \n");
$u = explode(" ",$line); // $u is the variable eg. an IPadress
while ($line = fscanf($fp,"%s",$u)) {
if(preg_match("/^$u/",$_SERVER['REMOTE_ADDR'])) {$badipadresss++;} // do something and continue scan
}
?>
Besides, fscanf()is much faster than fgets()
james at zephyr-works dot com ¶
23 years ago
fscanf works a little retardedly I've found. Instead of using just a plain %s you probably will need to use sets instead. Because it works so screwy compared to C/C++, fscanf does not have the ability to scan ahead in a string and pattern match correctly, so a seemingly perfect function call like:
fscanf($fh, "%s::%s");
With a file like:
user::password
Will not work. When fscanf looks for a string, it will look and stop at nothing except for a whitespace so :: and everything except whitespace is considered part of that string, however you can make it a little smarter by:
fscanf($fh, "%[a-zA-Z0-9,. ]::%[a-zA-Z0-9,. ]" $var1, $var2);
Which tells it that it can only accept a through z A through Z 0 through 9 a comma a period and a whitespace as input to the string, everything else cause it to stop taking in as input and continue parsing the line. This is very useful if you want to get a sentence into the string and you're not sure of exactly how many words to add, etc.
hdh265 at 163 dot com ¶
9 years ago
The use of PHP code in the ACM submission
Here is a sample solution for problem 1001 using PHP:
<?php
while (fscanf(STDIN, "%d%d", $a, $b) == 2) {
print ($a + $b) . "\n";
}
