Issue #61 Add form feed to trimmed characters

Author: mikehaertl

README.md

@@ -1,5 +1,5 @@
 php-shellcommand
-===========
+================
 
 [![GitHub Tests](https://github.com/mikehaertl/php-shellcommand/workflows/Tests/badge.svg)](https://github.com/mikehaertl/php-shellcommand/actions)
 [![Packagist Version](https://img.shields.io/packagist/v/mikehaertl/php-shellcommand?label=version)](https://packagist.org/packages/mikehaertl/php-shellcommand)
@@ -61,15 +61,15 @@ $command->addArg('--name=', "d'Artagnan");
 
 // Add argument with several values
 // results in --keys key1 key2
-$command->addArg('--keys', array('key1','key2'));
+$command->addArg('--keys', ['key1','key2']);
 ```
 
 ### Pipe Input Into Command
 
 From string:
 ```php
 <?php
-$command = new ('jq') // jq is a pretty printer
+$command = new ('jq'); // jq is a pretty printer
 $command->setStdIn('{"foo": 0}');
 if (!$command->execute()) {
     echo $command->getError();
@@ -115,19 +115,19 @@ fclose($fh);
 ```php
 <?php
 // Create command with options array
-$command = new Command(array(
+$command = new Command([
     'command' => '/usr/local/bin/mycommand',
 
     // Will be passed as environment variables to the command
-    'procEnv' => array(
+    'procEnv' => [
         'DEMOVAR' => 'demovalue'
-    ),
+    ],
 
     // Will be passed as options to proc_open()
-    'procOptions' => array(
+    'procOptions' => [
         'bypass_shell' => true,
-    ),
-));
+    ],
+]);
 ```
 
 ## API
@@ -185,7 +185,7 @@ pass `command`, `execCommand` and `args` as options. This will call the respecti
        and `=`, the (optional) `$value` will be separated by a space. The key will get
        escaped if `$escapeArgs` is `true`.
     * `$value`: The optional argument value which will get escaped if `$escapeArgs` is `true`.
-       An array can be passed to add more than one value for a key, e.g. `addArg('--exclude', array('val1','val2'))`
+       An array can be passed to add more than one value for a key, e.g. `addArg('--exclude', ['val1','val2'])`
        which will create the option "--exclude 'val1' 'val2'".
     * `$escape`: If set, this overrides the `$escapeArgs` setting and enforces escaping/no escaping
  * `setStdIn()`: String or resource to supply to command via standard input.

src/Command.php

@@ -328,30 +328,36 @@ public function addArg($key, $value = null, $escape = null)
 
     /**
      * @param bool $trim whether to `trim()` the return value. The default is `true`.
+     * @param string $characters the list of characters to trim. The default
+     * is ` \t\n\r\0\v\f`.
      * @return string the command output (stdout). Empty if none.
      */
-    public function getOutput($trim = true)
+    public function getOutput($trim = true, $characters = " \t\n\r\0\v\f")
     {
-        return $trim ? trim($this->_stdOut) : $this->_stdOut;
+        return $trim ? trim($this->_stdOut, $characters) : $this->_stdOut;
     }
 
     /**
      * @param bool $trim whether to `trim()` the return value. The default is `true`.
+     * @param string $characters the list of characters to trim. The default
+     * is ` \t\n\r\0\v\f`.
      * @return string the error message, either stderr or an internal message.
      * Empty string if none.
      */
-    public function getError($trim = true)
+    public function getError($trim = true, $characters = " \t\n\r\0\v\f")
     {
-        return $trim ? trim($this->_error) : $this->_error;
+        return $trim ? trim($this->_error, $characters) : $this->_error;
     }
 
     /**
      * @param bool $trim whether to `trim()` the return value. The default is `true`.
+     * @param string $characters the list of characters to trim. The default
+     * is ` \t\n\r\0\v\f`.
      * @return string the stderr output. Empty if none.
      */
-    public function getStdErr($trim = true)
+    public function getStdErr($trim = true, $characters = " \t\n\r\0\v\f")
     {
-        return $trim ? trim($this->_stdErr) : $this->_stdErr;
+        return $trim ? trim($this->_stdErr, $characters) : $this->_stdErr;
     }
 
     /**