+/**
+ * SquirrelMail wrapper for popen()/proc_open()
+ *
+ * This emulates popen() by using proc_open() if at all
+ * possible (reverts seamlessly to popen() if proc_open()
+ * is not supported in current PHP installation).
+ *
+ * This is intended for use with the related sq_pclose(),
+ * sq_get_pipe_stdout() and sq_get_pipe_stderr() functions,
+ * the latter of which add an easy interface for retrieving
+ * output from a child process that was opened with traditional
+ * popen() syntax (in write mode), while not breaking under
+ * earlier versions of PHP.
+ *
+ * @param string $command The command identifying what to
+ * execute in the child process.
+ * @param string $mode The desired mode for the
+ * unidirectional pipe that is returned;
+ * either 'r' for read or 'w' for write.
+ *
+ * @return resource A handle on the desired read or write pipe
+ * to the child process, or FALSE if the
+ * process cannot be created.
+ *
+ * @since 1.5.2
+ *
+ */
+function sq_popen($command, $mode) {
+
+ $mode = strtolower($mode{0});
+
+
+ if (!function_exists('proc_open'))
+ return popen($command, $mode);
+
+
+ // set up our process store if not done already
+ //
+ global $processes;
+ if (empty($processes))
+ $processes = array();
+
+
+ // define read, write and error pipes
+ //
+ $descriptors = array(0 => array('pipe', 'r'),
+ 1 => array('pipe', 'w'),
+ 2 => array('pipe', 'w'));
+
+
+ // start the child process
+ //
+ $proc = proc_open($command, $descriptors, $pipes);
+ if (!is_resource($proc))
+ return FALSE;
+
+
+ // when in read mode, we'll return a handle to the child's write pipe
+ //
+ if ($mode == 'r')
+ $return_value = $pipes[1];
+ else if ($mode == 'w')
+ $return_value = $pipes[0];
+ else
+ die('sq_popen() expects $mode to be "r" or "w"');
+
+
+ // store the handle to the process and its pipes
+ // internally, keyed by whatever handle we'll be
+ // returning
+ //
+ $processes[$return_value] = array($proc, $pipes);
+
+
+ return $return_value;
+
+}
+
+
+/**
+ * Get STDERR output from a child process
+ *
+ * This is designed to be used with processes that were
+ * opened with sq_popen(), and will return any output
+ * that may be available from STDERR of the child process
+ * at the current time.
+ *
+ * If a value is given for $timeout_seconds, this function
+ * will wait that long for output in case there is none
+ * right now.
+ *
+ * In PHP environments that do not support proc_open(),
+ * an empty string will always be returned.
+ *
+ * @param resource $handle The handle to the child process,
+ * as returned from sq_popen().
+ * @param int $timeout_seconds The number of seconds to wait
+ * for output if there is none
+ * available immediately (OPTIONAL;
+ * default is not to wait)
+ * @param boolean $quiet When TRUE, errors are silently
+ * ignored (OPTIONAL; default is TRUE).
+ *
+ * @return string Any STDERR output that may have been found.
+ *
+ * @since 1.5.2
+ *
+ */
+function sq_get_pipe_stderr($handle, $timeout_seconds=0, $quiet=TRUE) {
+
+ // yes, we are testing for proc_OPEN
+ // because we need to know how the
+ // handle was actually OPENED
+ //
+ if (!function_exists('proc_open'))
+ return '';
+
+
+ // get our process out of the process store
+ //
+ global $processes;
+ if (!is_array($processes) || !isset($processes[$handle])) {
+ if (!quiet) {
+ plain_error_message(_("Failed to find corresponding open process handle"));
+ }
+ return '';
+ }
+ $proc = $processes[$handle];
+
+
+ // get all we can from stderr, don't wait longer
+ // than our timeout for input
+ //
+ $contents = '';
+ $read = array($proc[1][2]);
+ $write = NULL;
+ $except = NULL;
+ if (stream_select($read, $write, $except, $timeout_seconds))
+ while (!feof($proc[1][2])) $contents .= fread($proc[1][2], 8192);
+ return $contents;
+
+}
+
+
+/**
+ * Get STDOUT output from a child process
+ *
+ * This is designed to be used with processes that were
+ * opened with sq_popen(), and will return any output
+ * that may be available from STDOUT of the child process
+ * at the current time.
+ *
+ * If a value is given for $timeout_seconds, this function
+ * will wait that long for output in case there is none
+ * right now.
+ *
+ * In PHP environments that do not support proc_open(),
+ * an empty string will always be returned.
+ *
+ * @param resource $handle The handle to the child process,
+ * as returned from sq_popen().
+ * @param int $timeout_seconds The number of seconds to wait
+ * for output if there is none
+ * available immediately (OPTIONAL;
+ * default is not to wait)
+ * @param boolean $quiet When TRUE, errors are silently
+ * ignored (OPTIONAL; default is TRUE).
+ *
+ * @return string Any STDOUT output that may have been found.
+ *
+ * @since 1.5.2
+ *
+ */
+function sq_get_pipe_stdout($handle, $timeout_seconds=0, $quiet=TRUE) {
+
+ // yes, we are testing for proc_OPEN
+ // because we need to know how the
+ // handle was actually OPENED
+ //
+ if (!function_exists('proc_open'))
+ return '';
+
+
+ // get our process out of the process store
+ //
+ global $processes;
+ if (!is_array($processes) || !isset($processes[$handle])) {
+ if (!quiet) {
+ plain_error_message(_("Failed to find corresponding open process handle"));
+ }
+ return '';
+ }
+ $proc = $processes[$handle];
+
+
+ // get all we can from stdout, don't wait longer
+ // than our timeout for input
+ //
+ $contents = '';
+ $read = array($proc[1][1]);
+ $write = NULL;
+ $except = NULL;
+ if (stream_select($read, $write, $except, $timeout_seconds))
+ while (!feof($proc[1][1])) $contents .= fread($proc[1][1], 8192);
+ return $contents;
+
+}
+
+
+/**
+ * SquirrelMail wrapper for pclose()/proc_close()
+ *
+ * This is designed to be used with processes that were
+ * opened with sq_popen(), and will correctly close
+ * all pipes/handles that were opened as well as the
+ * child process itself.
+ *
+ * @param resource $handle The handle to the child process,
+ * as returned from sq_popen().
+ * @param boolean $quiet When TRUE, errors are silently
+ * ignored (OPTIONAL; default is TRUE).
+ *
+ * @return int The termination status of the child process.
+ *
+ * @since 1.5.2
+ *
+ */
+function sq_pclose($handle, $quiet=TRUE) {
+
+ // yes, we are testing for proc_OPEN
+ // because we need to know how the
+ // handle was actually OPENED
+ //
+ if (!function_exists('proc_open'))
+ return pclose($handle);
+
+
+ // get our process out of the process store
+ //
+ global $processes;
+ if (!is_array($processes) || !isset($processes[$handle])) {
+ if (!quiet) {
+ plain_error_message(_("Failed to find corresponding open process handle"));
+ }
+ return 127;
+ }
+ $proc = $processes[$handle];
+ unset($processes[$handle]);
+
+
+ // close all pipes
+ //
+ fclose($proc[1][0]);
+ fclose($proc[1][1]);
+ fclose($proc[1][2]);
+
+
+ // close process
+ //
+ return proc_close($proc[0]);
+
+}
+
+
+/**
+ * Sanitize a value using htmlspecialchars() or similar, but also
+ * recursively run htmlspecialchars() (or similar) on array keys
+ * and values.
+ *
+ * If $value is not a string or an array with strings in it,
+ * the value is returned as is.
+ *
+ * @param mixed $value The value to be sanitized.
+ * @param mixed $quote_style Either boolean or an integer. If it
+ * is an integer, it must be the PHP
+ * constant indicating if/how to escape
+ * quotes: ENT_QUOTES, ENT_COMPAT, or
+ * ENT_NOQUOTES. If it is a boolean value,
+ * it must be TRUE and thus indicates
+ * that the only sanitizing to be done
+ * herein is to replace single and double
+ * quotes with ' and ", no other
+ * changes are made to $value. If it is
+ * boolean and FALSE, behavior reverts
+ * to same as if the value was ENT_QUOTES
+ * (OPTIONAL; default is ENT_QUOTES).
+ *
+ * @return mixed The sanitized value.
+ *
+ * @since 1.5.2
+ *
+ **/
+function sq_htmlspecialchars($value, $quote_style=ENT_QUOTES) {
+
+ if ($quote_style === FALSE) $quote_style = ENT_QUOTES;
+
+ // array? go recursive...
+ //
+ if (is_array($value)) {
+ $return_array = array();
+ foreach ($value as $key => $val) {
+ $return_array[sq_htmlspecialchars($key, $quote_style)]
+ = sq_htmlspecialchars($val, $quote_style);
+ }
+ return $return_array;
+
+ // sanitize strings only
+ //
+ } else if (is_string($value)) {
+ if ($quote_style === TRUE)
+ return str_replace(array('\'', '"'), array(''', '"'), $value);
+ else
+ return htmlspecialchars($value, $quote_style);
+ }
+
+ // anything else gets returned with no changes
+ //
+ return $value;
+
+}