readline
(PHP 4, PHP 5)
readline — Reads 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());
?>
Коментарии
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
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";
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 $prompt;
return rtrim( fgets( STDIN ), "\n" );
}
Note that readline() will return boolean "false" when the user presses CTRL+D.
If you want to prefill the prompt with something when using readline, this worked for me:
<?php
function readline_callback($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: ' . $prompt_answer . "\n";
?>
I wanted a function that would timeout if readline was waiting too long... this works on php CLI on linux:
<?php
function readline_timeout($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.
The readline library is not available on Windows.
<?php
if (PHP_OS == 'WINNT') {
echo '$ ';
$line = stream_get_line(STDIN, 1024, PHP_EOL);
} else {
$line = readline('$ ');
}
?>
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: ');
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.
Works under windows, and under php 7.2.0 :
$arr = [];
for ($i=0; $i < 3; $i++) {
$arr[$i] = readline("Commande : ");
}
// Output
print_r($arr);
----------
Output:
Commande : 658
Commande : 965
Commande : 478
Array
(
[0] => 658
[1] => 965
[2] => 478
)
If you want to block remove previous text and wonder that an empty string does not work: the workaround is to use an space with cursor left:
<?php
echo "> ";
readline(" \e[D");
?>
Christian's code works well, but if you want to be able to hide the user input and not echo it to screen, you need to add -s to the read command. The code below is an expanded function that allows an optional prompt and optional hiding of the input:
function read_password($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;
}
for some reason readline() doesn't support unicode, readline STRIPS æøåÆØÅ - for a readline function with unicode support, try
<?php
function readline_with_unicode_support(?string $prompt = null)/*: string|false*/
{
if ($prompt !== null && $prompt !== '') {
echo $prompt;
}
$line = fgets(STDIN);
// readline() removes the trailing newline, fgets does not,
// to emulate the real readline(), we also need to remove it
if ($line !== false && strlen($line) >= strlen(PHP_EOL) && substr_compare($line, PHP_EOL, -strlen(PHP_EOL), strlen(PHP_EOL), true) === 0) {
$line = substr($line, 0, -strlen(PHP_EOL));
}
return $line;
}
<?php
/**
* readline() with unicode support
* php's builtin readline has dodgy unicode support, it only works
* with the correct environment locale settings, it doesn't seem to work at Cygwin (strips æøåÆØÅ),
* and it has historically had bugs like https://bugs.php.net/bug.php?id=81598
* meanwhile this readline has consistent unicode support across all platforms (including Cygwin)
* and doesn't care about locale settings.
*
* @param string $prompt
* @return string|false
*/
function readline_with_unicode_support(?string $prompt = null)/*: string|false*/
{
if ($prompt !== null && $prompt !== '') {
echo $prompt;
}
$line = fgets(STDIN);
// readline() removes the trailing newline, fgets() does not,
// to emulate the real readline(), we also need to remove it
if ($line !== false && strlen($line) >= strlen(PHP_EOL) && substr_compare($line, PHP_EOL, -strlen(PHP_EOL)) === 0) {
$line = substr($line, 0, -strlen(PHP_EOL));
}
return $line;
}
<?
/*
*
I've noticed strange behavior from readline while using it for user input from a CLI.
When I press multiple tabs it prints a scandir to the input stream.
Below is the code:
*
*/
$msg = "";
while ($msg != "quit")
{
while (($msg == "") || ($msg == "\r"))
$msg = readline ("> ");
}
?>
To stop auto complete , register an auto complete function that returns no matches to auto complete.
function dontAutoComplete ($input, $index)
{ return ([]); }
readline_completion_function ("dontAutoComplete");