bug 978: New helper function runCommand() -> reduce boilerplate code

Signed-off-by: Michael Tänzer <neo@nhng.de>

1 files changed, 71 insertions, 9 deletions

diff --git a/includes/lib/general.php b/includes/lib/general.php
index 6cfbd10..d91b24e 100644
--- a/includes/lib/general.php
+++ b/includes/lib/general.php
@@ -48,15 +48,15 @@ function get_user_id_from_cert($serial, $issuer_cn)
 }
 
 /**
-* Produces a log entry with the error message with log level E_USER_WARN
-* and a random ID an returns a message that can be displayed to the user
-* including the generated ID
-*
-* @param $errormessage string
-* 		The error message that should be logged
-* @return string containing the generated ID that can be displayed to the
-* 		user
-*/
+ * Produces a log entry with the error message with log level E_USER_WARN
+ * and a random ID an returns a message that can be displayed to the user
+ * including the generated ID
+ *
+ * @param $errormessage string
+ * 		The error message that should be logged
+ * @return string containing the generated ID that can be displayed to the
+ * 		user
+ */
 function failWithId($errormessage) {
 	$errorId = rand();
 	trigger_error("$errormessage. ID: $errorId", E_USER_WARNING);
@@ -68,3 +68,65 @@ function failWithId($errormessage) {
 	$errorId);
 }
 
+
+/**
+ * Runs a command on the shell and return it's exit code and output
+ * 
+ * @param string $command
+ * 		The command to run. Make sure that you escapeshellarg() any non-constant
+ * 		parts as this is executed on a shell!
+ * @param string|bool $input
+ * 		The input that is passed to the command via STDIN, if true the real
+ * 		STDIN is passed through
+ * @param string|bool $output
+ * 		The output the command wrote to STDOUT (this is passed as reference),
+ * 		if true the output will be written to the real STDOUT. Output is ignored
+ * 		by default
+ * @param string|bool $errors
+ * 		The output the command wrote to STDERR (this is passed as reference),
+ * 		if true (default) the output will be written to the real STDERR
+ * 
+ * @return int|bool
+ * 		The exit code of the command, true if the execution of the command
+ * 		failed (true because then
+ * 		<code>if (runCommand('echo "foo"')) handle_error();</code> will work)
+ */
+function runCommand($command, $input = "", &$output = null, &$errors = true) {
+	$descriptorspec = array();
+	
+	if ($input !== true) {
+		$descriptorspec[0] = array("pipe", "r"); // STDIN for child
+	}
+	
+	if ($output !== true) {
+		$descriptorspec[1] = array("pipe", "w"); // STDOUT for child
+	}
+	
+	if ($errors !== true) {
+		$descriptorspec[2] = array("pipe", "w"); // STDERR for child
+	}
+	
+	$proc = proc_open($command, $descriptorspec, $pipes);
+	
+	if (is_resource($proc))
+	{
+		if ($input !== true) {
+			fwrite($pipes[0], $input);
+			fclose($pipes[0]);
+		}
+		
+		if ($output !== true) {
+			$output = stream_get_contents($pipes[1]);
+		}
+		
+		if ($errors !== true) {
+			$errors = stream_get_contents($pipes[2]);
+		}
+		
+		return proc_close($proc);
+		
+	} else {
+		return true;
+	}
+}
+