PHP Conference Nagoya 2025

readline

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

readlineReads a line

Description

readline(?string $prompt = null): string|false

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. If there is no more data to read, then false is returned.

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());
?>

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User Contributed Notes 5 notes

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16
Antony Penn
4 years ago
Christian's code works well, but if you want to be able to hide the user input and not echo it to screen, you need to add -s to the read command. The code below is an expanded function that allows an optional prompt and optional hiding of the input:

function read_password($prompt=null, $hide=false)
{
if($prompt) print $prompt;
$s = ($hide) ? '-s' : '';
$f=popen("read $s; echo \$REPLY","r");
$input=fgets($f,100);
pclose($f);
if($hide) print "\n";
return $input;
}
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7
turdsurfer
7 years ago
If your CLI script accepts input from STDIN and you also want it to prompt for a password (e.g. as mysql client does), then readline() won't work for you.
What you need to do is read from the terminal device as shown below.

function readline_terminal($prompt = '') {
$prompt && print $prompt;
$terminal_device = '/dev/tty';
$h = fopen($terminal_device, 'r');
if ($h === false) {
#throw new RuntimeException("Failed to open terminal device $terminal_device");
return false; # probably not running in a terminal.
}
$line = rtrim(fgets($h),"\r\n");
fclose($h);
return $line;
}
$pass = readline_terminal('Password: ');
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2
cox at idecnet dot com
22 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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0
Anonymous
7 years ago
a few observations....

I use Cygwin PHP v7 and readline is available. The readline_list_history() function though is not defined.

A prompt with escape sequences are sanitized, so use something like:

<?php
echo("\e[0m\e[34mPromt>\e[0m");
$inp = readline(' ');
?>

I have not fully documented it, but I see that sometimes strings beginning with punctuation characters do not make it into the history with readline_add_history(). They also sometimes clear the prompt string.
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-1
rojaro at gmail dot com
16 years ago
Note that readline() will return boolean "false" when the user presses CTRL+D.
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