PHP 7.0.6 Released

readline

(PHP 4, PHP 5, PHP 7)

readlineReads a line

Description

string readline ([ string $prompt ] )

Reads a single line from the user. You must add this line to the history yourself using readline_add_history().

Parameters

prompt

You may specify a string with which to prompt the user.

Return Values

Returns a single string from the user. The line returned has the ending newline removed.

Examples

Example #1 readline() Example

<?php
//get 3 commands from user
for ($i=0$i 3$i++) {
        
$line readline("Command: ");
        
readline_add_history($line);
}

//dump history
print_r(readline_list_history());

//dump variables
print_r(readline_info());
?>

User Contributed Notes

Anonymous
4 years ago
The readline library is not available on Windows.

<?php
if (PHP_OS == 'WINNT') {
  echo
'$ ';
 
$line = stream_get_line(STDIN, 1024, PHP_EOL);
} else {
 
$line = readline('$ ');
}
?>
rojaro at gmail dot com
7 years ago
Note that readline() will return boolean "false" when the user presses CTRL+D.
soletan at toxa dot de
9 years ago
To haukew at gmail dot com:

readline provides more features than reading a single line of input ... your example misses line editing and history. If you don't need that, use something as simple as this:

function readline( $prompt = '' )
{
    echo $prompt;
    return rtrim( fgets( STDIN ), "\n" );
}
sean
6 years ago
I wanted a function that would timeout if readline was waiting too long... this works on php CLI on linux:

<?php

function readline_timeout($sec, $def)
{
    return
trim(shell_exec('bash -c ' .
       
escapeshellarg('phprlto=' .
           
escapeshellarg($def) . ';' .
           
'read -t ' . ((int)$sec) . ' phprlto;' .
           
'echo "$phprlto"')));
}

?>

Just call readline_timeout(5, 'whatever') to either read something from stdin, or timeout in 5 seconds and default to 'whatever'.  I tried just using shell_exec without relying on bash -c, but that didn't work for me, so I had to go the round about way.
roddric dot kasen at gmail dot com
1 month ago
<?php

class ConsoleQuestion
{

    function
readline()
    {
        return
rtrim(fgets(STDIN));
    }
}

//Example1
$line = new ConsoleQuestion();
$prompt = "What Is Your Name: ";
echo
$prompt;
$answer = $line->readline();
echo
"You Entered: " . $answer;

//Example2 (comment Ex1 then uncomment Ex2)
/*$prompt = "What Is Your Name: ";
echo $prompt;
$answer =  "You Entered: " . rtrim( fgets( STDIN ));
echo $answer;*/

?>
taneli at crasman dot fi
7 years ago
If you want to prefill the prompt with something when using readline, this worked for me:

<?php
 
function readline_callback($ret)
  {
    global
$prompt_answer, $prompt_finished;
   
$prompt_answer = $ret;
   
$prompt_finished = TRUE;
   
readline_callback_handler_remove();
  }

 
readline_callback_handler_install('Enter some text> ',
                                   
'readline_callback');

 
$prefill = 'foobar';
  for (
$i = 0; $i < strlen($prefill); $i++)
  {
   
readline_info('pending_input', substr($prefill, $i, 1));
   
readline_callback_read_char();
  }

 
$prompt_finished = FALSE;
 
$prompt_answer = FALSE;
  while (!
$prompt_finished)
   
readline_callback_read_char();
  echo
'You wrote: ' . $prompt_answer . "\n";
?>
christian at gaeking dot de
12 years ago
A workaround if readline is not compiled into php, because for example the command is only needed within an installation routine. It works as follows under Linux:

$f=popen("read; echo \$REPLY","r");
$input=fgets($f,100);
pclose($f);       
echo "Entered: $input\n";
cox at idecnet dot com
14 years ago
In CGI mode be sure to call:

ob_implicit_flush(true);

at the top of your script if you want to be able to output data before and after the prompt.

-- Tomas V.V.Cox
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