From 49a1b33df4074b6be58d2e23759801f2eaefbd16 Mon Sep 17 00:00:00 2001
From: Uwe Steinmann <steinm@debian.org>
Date: Mon, 16 May 2022 15:54:04 +0200
Subject: [PATCH] check extension dependency on shell commands

---
 CHANGELOG                     |  1 +
 inc/inc.ClassExtensionMgr.php |  8 ++++++++
 inc/inc.Utils.php             | 31 +++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index 5f7f5d223..ab08c277e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -4,6 +4,7 @@
 - add hook additionalDocumentContentInfo
 - add restapi function 'statstotal'
 - custom attributes of type 'date' regard the date format
+- check extension dependency on shell commands
 
 --------------------------------------------------------------------------------
                      Changes in version 5.1.25
diff --git a/inc/inc.ClassExtensionMgr.php b/inc/inc.ClassExtensionMgr.php
index b70f0fe3b..07e7d51d3 100644
--- a/inc/inc.ClassExtensionMgr.php
+++ b/inc/inc.ClassExtensionMgr.php
@@ -441,6 +441,14 @@ class SeedDMS_Extension_Mgr {
 							}
 						}
 						break;
+					case 'cmd':
+						if(is_array($dval) && $dval) {
+							foreach($dval as $d) {
+								if(!commandExists($d))
+									$this->errmsgs[] = sprintf("Missing command '%s'", $d);
+							}
+						}
+						break;
 					default:
 						$tmp = explode('-', $dval, 2);
 						if(isset($this->extconf[$dkey]['version'])) {
diff --git a/inc/inc.Utils.php b/inc/inc.Utils.php
index 3192b6fbd..6628a5df2 100644
--- a/inc/inc.Utils.php
+++ b/inc/inc.Utils.php
@@ -696,6 +696,37 @@ function addDirSep($str) { /* {{{ */
 		return trim($str);
 } /* }}} */
 
+/**
+ * Determines if a command exists on the current environment
+ *
+ * @param string $command The command to check
+ * @return bool True if the command has been found ; otherwise, false.
+ */
+function commandExists ($command) {
+	$whereIsCommand = (PHP_OS == 'WINNT') ? 'where' : 'command -v';
+
+	$process = proc_open(
+		"$whereIsCommand $command",
+		array(
+			0 => array("pipe", "r"), //STDIN
+			1 => array("pipe", "w"), //STDOUT
+			2 => array("pipe", "w"), //STDERR
+		),
+		$pipes
+	);
+	if ($process !== false) {
+		$stdout = stream_get_contents($pipes[1]);
+		$stderr = stream_get_contents($pipes[2]);
+		fclose($pipes[1]);
+		fclose($pipes[2]);
+		proc_close($process);
+
+		return $stdout != '';
+	}
+
+	return false;
+}
+
 /**
  * Send a file from disk to the browser
  *