Differential D20980 Diff 49996 src/filesystem/PhutilProcessQuery.php

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src/filesystem/PhutilProcessQuery.php

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				<?php

				final class PhutilProcessQuery
				extends Phobject {

				private $isOverseer;
				private $instances;

				public function withIsOverseer($is_overseer) {
				$this->isOverseer = $is_overseer;
				return $this;
				}

				public function withInstances(array $instances) {
				$this->instances = $instances;
				return $this;
				}

				public function execute() {
				if (phutil_is_windows()) {
				throw new Exception(
				pht(
				'Querying system processes is not currently supported on '.
				'Windows.'));
				}

				// TODO: See T12827. This formulation likely does not work properly on
				// Solaris.

				list($processes) = execx('ps -o pid,command -a -x -w -w -w');
				$processes = phutil_split_lines($processes, false);

				$refs = array();
				foreach ($processes as $process) {
				$parts = preg_split('/\s+/', trim($process), 2);
				list($pid, $command) = $parts;

				$ref = id(new PhutilProcessRef())
				->setPID((int)$pid);

				$argv = $this->getArgv($pid, $command);
				$ref->setArgv($argv);

				// If this is an overseer and the command has a "-l" ("Label") argument,
				// the argument contains the "PHABRICATOR_INSTANCE" value for the daemon.
				// Parse it out and annotate the process.
				$instance = null;
				if ($ref->getIsOverseer()) {
				$matches = null;
				if (preg_match('/-l (\S+)/', $command, $matches)) {
				$instance = $matches[1];
				}
				}

				$ref->setInstance($instance);

				$refs[] = $ref;
				}

				if ($this->isOverseer !== null) {
				foreach ($refs as $key => $ref) {
				if ($ref->getIsOverseer() !== $this->isOverseer) {
				unset($refs[$key]);
				}
				}
				}

				if ($this->instances) {
				$instances_map = array_fuse($this->instances);
				foreach ($refs as $key => $ref) {
				if (!isset($instances_map[$ref->getInstance()])) {
				unset($refs[$key]);
				}
				}
				}

				return array_values($refs);
				}

				private function getArgv($pid, $command) {

				// In the output of "ps", arguments in process titles are not escaped, so
				// we can not distinguish between the processes created by running these
				// commands by looking only at the output of "ps":
				//
				// echo 'a b'
				// echo a b
				//
				// Both commands will have the same process title in the output of "ps".

				// This means we may split the command incorrectly in the general case,
				// and this misparsing may be important if the process binary resides in
				// a directory with spaces in its path and we're trying to identify which
				// binary a process is running.

				// On Ubuntu, and likely most other Linux systems, we can get a raw
				// command line from "/proc" with arguments delimited by "\0".

				// On macOS, there's no "/proc" and we don't currently have a robust way
				// to split the process command in a way that parses spaces properly, so
				// fall back to a best effort based on the output of "ps". This is almost
				// always correct, since it is uncommon to put binaries under paths with
				// spaces in them.

				$proc_cmdline = sprintf('/proc/%d/cmdline', $pid);
				try {
				$argv = Filesystem::readFile($proc_cmdline);
				$argv = explode("\0", $argv);

				// The output itself is terminated with "\0", so remove the final empty
				// argument.
				if (last($argv) === '') {
				array_pop($argv);
				}

				return $argv;
				} catch (Exception $ex) {
				// If we fail to read "/proc", fall through to less reliable methods.
				}

				// If we haven't found a better source, just split the "ps" output on
				// spaces.
				return preg_split('/\s+/', $command);
				}
				}