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 — Parses input from a file according to a format
Description
The function fscanf() is similar to
sscanf(), but it takes its input from a file
associated with stream and interprets the
input according to the specified format.
Any whitespace in the format string matches any whitespace in the input
stream. This means that even a tab (\t) in the format
string can match a single space character in the input stream.
Each call to fscanf() reads one line from the file.
Parameters
-
stream -
A file system pointer resource that is typically created using fopen().
-
format -
The interpreted format for
string, which is described in the documentation for sprintf() with following differences:- Function is not locale-aware.
-
F,g,Gandbare not supported. -
Dstands for decimal number. -
istands for integer with base detection. -
nstands for number of characters processed so far. -
sstops reading at any whitespace character. -
*instead ofargnum$suppresses the assignment of this conversion specification.
-
vars -
The optional assigned values.
Return Values
If only two parameters were passed to this function, the values parsed will be returned as an array. Otherwise, if optional parameters are passed, the function will return the number of assigned values. The optional parameters must be passed by reference.
If there are more substrings expected in the format
than there are available within string,
null will be returned. On other errors, false will be returned.
Examples
Example #1 fscanf() Example
<?php
$handle = fopen("users.txt", "r");
while ($userinfo = fscanf($handle, "%s\t%s\t%s\n")) {
list ($name, $profession, $countrycode) = $userinfo;
//... do something with the values
}
fclose($handle);
?>
Example #2 Contents of users.txt
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";
}
