fgetc

(PHP 4, PHP 5, PHP 7, PHP 8)

fgetc — 从文件指针中读取字符

说明

fgetc ( resource $handle ) : string

从文件句柄中获取一个字符。

参数

handle: 文件指针必须是有效的，必须指向由 fopen() 或 fsockopen() 成功打开的文件(并还未由 fclose() 关闭)。

返回值

返回一个包含有一个字符的字符串，该字符从 handle 指向的文件中得到。碰到 EOF 则返回 false。

Warning

此函数可能返回布尔值 false，但也可能返回等同于 false 的非布尔值。请阅读布尔类型章节以获取更多信息。应使用 === 运算符来测试此函数的返回值。

范例

Example #1 一个 fgetc() 例子


<?php
$fp = fopen('somefile.txt', 'r');
if (!$fp) {
    echo 'Could not open file somefile.txt';
}
while (false !== ($char = fgetc($fp))) {
    echo "$char\n";
}
?>

注释

Note: 此函数可安全用于二进制对象。

参见

fread() - 读取文件（可安全用于二进制文件）
fopen() - 打开文件或者 URL
popen() - 打开进程文件指针
fsockopen() - 打开一个网络连接或者一个Unix套接字连接
fgets() - 从文件指针中读取一行

User Contributed Notes

seraclimov at yandex dot ru 29-Jan-2018 04:57


You can't just simple print separated characters of a text which is encoded in multibyte character set like this;

Because fgetc() will break each multibyte character on its every byte. Consider this example: 



<?php

$path = 'foo/cyrillic.txt';

$handle = fopen($path, 'rb');

while (FALSE !== ($ch = fgetc($handle))) {

    $curs = ftell($hanlde);

    print "[$curs:] $ch\n";

}

/* The result will be something like this:

<

[1]: <

[2]: h

[3]: 2

[4]: >

[5]: ?

[6]: ?

[7]: ?

[8]: ?

[9]: ?

[10]: ?

[11]:  

[12]: ?

[13]: ?

[14]: ?

[15]: ?

[16]: ?

*/ ?>



I don't think this is the best, but it can be a workaround:

<?php

$path = 'path/to/your/file.ext';



if (!$handle = fopen($path, 'rb')) {

    echo "Can't open ($path) file';

    exit;

}



$mbch = '';    // keeps the first byte of 2-byte cyrillic letters

while (FALSE !== ($ch = fgetc($handle))) {        

    //check for the sign of 2-byte cyrillic letters    

    if (empty($mbch) && (FALSE !== array_search(ord($ch), Array(208,209,129)))) {

        $mbch = $ch;    // keep the first byte

        continue;

    }

    $curs = ftell($handle);

    print "[$curs]: " . $mbch . $ch . PHP_EOL;

    // or print "[$curs]: $mbch$ch\n";

    if (!empty($mbch)) $mbch = '';    // erase the byte after using

}

?>

Anonymous 30-Jun-2017 02:10


If you call fgetc(HANDLE) multiple times you must clear buffer before, thus get all unwanted chars to the new new line character.



while (true) {



    //clear buffer - read all unwanted characters

    while(fgetc(STDIN) != "\n");

    

    //get first character from STDIN

    $first = fgetc(STDIN);

}

sfinktah at php dot spamtrak dot org 22-Mar-2011 06:33


To read a single key-press in CLI mode, you can either use ncurses (which will probably require additional modules for PHP) or get nasty with the *nix "/bin/stty" command)



<?php

   function stty($options) {

      exec($cmd = "/bin/stty $options", $output, $el);

      $el AND die("exec($cmd) failed");

      return implode(" ", $output);

   }



   function getchar($echo = false) {

      $echo = $echo ? "" : "-echo";



      # Get original settings

      $stty_settings = preg_replace("#.*; ?#s", "", stty("--all"));



      # Set new ones

      stty("cbreak $echo");



      # Get characters until a PERIOD is typed,  

      # showing their hexidecimal ordinal values.

      printf("> ");

      do {

         printf("%02x ", ord($c = fgetc(STDIN)));

      } while ($c != '.');



      # Return settings

      stty($stty_settings);

   }



   getchar();

?>

alex at alexdemers dot me 11-May-2009 10:30


The best and simplest way to get input from a user in the CLI with only PHP is to use fgetc() function with the STDIN constant:



<?php



echo 'Are you sure you want to quit? (y/n) ';

$input = fgetc(STDIN);



if ($input == 'y')

{

    exit(0);

}



?>

ktraas at gmail dot com (Kevin Traas) 23-Mar-2009 07:08


I was using command-line PHP to create an interactive script and wanted the user to enter just one character of input - in response a Yes/No question.  Had some trouble finding a way to do so using fgets(), fgetc(), various suggestions using readline(), popen(), etc.  Came up with the following that works quite nicely:



$ans = strtolower( trim( `bash -c "read -n 1 -t 10 ANS ; echo \\\$ANS"` ) );