Struct procfs::process::Process

pub struct Process {
    pub pid: i32,
    pub stat: Stat,
    pub owner: u32,
    // some fields omitted
}

Represents a process in /proc/<pid>.

The stat structure is pre-populated because it’s useful info, but other data is loaded on demand (and so might fail, if the process no longer exist).

Fields

pid: i32

The process ID

(same as the Stat.pid field).

stat: Stat

Process status, based on the /proc/<pid>/stat file.

owner: u32

The user id of the owner of this process

Implementations

impl Process

pub fn limits(&self) -> ProcResult<Limits>

Return the limits for this process

impl Process

pub fn mountstats(&self) -> ProcResult<Vec<MountStat>>

Returns the MountStat data for this processes mount namespace.

pub fn mountinfo(&self) -> ProcResult<Vec<MountInfo>>

Returns info about the mountpoints in this this process’s mount namespace

This data is taken from the /proc/[pid]/mountinfo file

(Since Linux 2.6.26)

impl Process

pub fn namespaces(&self) -> ProcResult<Vec<Namespace>>

Describes namespaces to which the process with the corresponding PID belongs. Doc reference: https://man7.org/linux/man-pages/man7/namespaces.7.html

impl Process

pub fn new(pid: pid_t) -> ProcResult<Process>

Returns a Process based on a specified PID.

This can fail if the process doesn’t exist, or if you don’t have permission to access it.

pub fn new_with_root(root: PathBuf) -> ProcResult<Process>

Returns a Process based on a specified /proc/<pid> path.

pub fn myself() -> ProcResult<Process>

Returns a Process for the currently running process.

This is done by using the /proc/self symlink

pub fn cmdline(&self) -> ProcResult<Vec<String>>

Returns the complete command line for the process, unless the process is a zombie.

pub fn pid(&self) -> pid_t

Returns the process ID for this process.

pub fn is_alive(&self) -> bool

Is this process still alive?

pub fn cwd(&self) -> ProcResult<PathBuf>

Retrieves current working directory of the process by dereferencing /proc/<pid>/cwd symbolic link.

This method has the following caveats:

• if the pathname has been unlinked, the symbolic link will contain the string “ (deleted)“ appended to the original pathname

• in a multithreaded process, the contents of this symbolic link are not available if the main thread has already terminated (typically by calling pthread_exit(3))

• permission to dereference or read this symbolic link is governed by a ptrace(2) access mode PTRACE_MODE_READ_FSCREDS check

pub fn root(&self) -> ProcResult<PathBuf>

Retrieves current root directory of the process by dereferencing /proc/<pid>/root symbolic link.

This method has the following caveats:

• if the pathname has been unlinked, the symbolic link will contain the string “ (deleted)“ appended to the original pathname

• in a multithreaded process, the contents of this symbolic link are not available if the main thread has already terminated (typically by calling pthread_exit(3))

• permission to dereference or read this symbolic link is governed by a ptrace(2) access mode PTRACE_MODE_READ_FSCREDS check

pub fn environ(&self) -> ProcResult<HashMap<OsString, OsString>>

Gets the current environment for the process. This is done by reading the /proc/pid/environ file.

pub fn exe(&self) -> ProcResult<PathBuf>

Retrieves the actual path of the executed command by dereferencing /proc/<pid>/exe symbolic link.

This method has the following caveats:

• if the pathname has been unlinked, the symbolic link will contain the string “ (deleted)“ appended to the original pathname

• in a multithreaded process, the contents of this symbolic link are not available if the main thread has already terminated (typically by calling pthread_exit(3))

• permission to dereference or read this symbolic link is governed by a ptrace(2) access mode PTRACE_MODE_READ_FSCREDS check

pub fn io(&self) -> ProcResult<Io>

Return the Io stats for this process, based on the /proc/pid/io file.

(since kernel 2.6.20)

pub fn maps(&self) -> ProcResult<Vec<MemoryMap>>

Return a list of the currently mapped memory regions and their access permissions, based on the /proc/pid/maps file.

pub fn smaps(&self) -> ProcResult<Vec<(MemoryMap, MemoryMapData)>>

Returns a list of currently mapped memory regions and verbose information about them, such as memory consumption per mapping, based on the /proc/pid/smaps file.

(since Linux 2.6.14 and requires CONFIG_PROG_PAGE_MONITOR)

pub fn fd_count(&self) -> ProcResult<usize>

Gets the number of open file descriptors for a process

pub fn fd(&self) -> ProcResult<Vec<FDInfo>>

Gets a list of open file descriptors for a process

pub fn coredump_filter(&self) -> ProcResult<Option<CoredumpFlags>>

Lists which memory segments are written to the core dump in the event that a core dump is performed.

By default, the following bits are set: 0, 1, 4 (if the CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS kernel configuration option is enabled), and 5. This default can be modified at boot time using the core dump_filter boot option.

This function will return Err(ProcError::NotFound) if the coredump_filter file can’t be found. If it returns Ok(None) then the process has no coredump_filter

pub fn autogroup(&self) -> ProcResult<String>

Gets the process’s autogroup membership

(since Linux 2.6.38 and requires CONFIG_SCHED_AUTOGROUP)

pub fn auxv(&self) -> ProcResult<HashMap<u32, u32>>

Get the process’s auxiliary vector

(since 2.6.0-test7)

pub fn wchan(&self) -> ProcResult<String>

Gets the symbolic name corresponding to the location in the kernel where the process is sleeping.

(since Linux 2.6.0)

pub fn status(&self) -> ProcResult<Status>

Return the Status for this process, based on the /proc/[pid]/status file.

pub fn stat(&self) -> ProcResult<Stat>

Returns the status info from /proc/[pid]/stat.

Note that this data comes pre-loaded in the stat field. This method is useful when you get the latest status data (since some of it changes while the program is running)

pub fn loginuid(&self) -> ProcResult<u32>

Gets the process’ login uid. May not be available.

pub fn oom_score(&self) -> ProcResult<u32>

The current score that the kernel gives to this process for the purpose of selecting a process for the OOM-killer

A higher score means that the process is more likely to be selected by the OOM-killer. The basis for this score is the amount of memory used by the process, plus other factors.

(Since linux 2.6.11)

pub fn statm(&self) -> ProcResult<StatM>

Set process memory information

Much of this data is the same as the data from stat() and status()

pub fn task_main_thread(&self) -> ProcResult<Task>

Return a task for the main thread of this process

pub fn schedstat(&self) -> ProcResult<Schedstat>

Return the Schedstat for this process, based on the /proc/<pid>/schedstat file.

(Requires CONFIG_SCHED_INFO)

pub fn tasks(&self) -> ProcResult<TasksIter>

Iterate over all the Tasks (aka Threads) in this process

Note that the iterator does not receive a snapshot of tasks, it is a lazy iterator over whatever happens to be running when the iterator gets there, see the examples below.

Examples

Simple iteration over subtasks

If you want to get the info that most closely matches what was running when you call tasks you should collect them as quikcly as possible, and then run processing over that collection:

let name = "testing:example";
let t = thread::Builder::new().name(name.to_string())
  .spawn(move || { // do work
  })?;

let proc = Process::myself()?;

// Collect a snapshot
let threads: Vec<_> = proc.tasks()?.flatten().map(|t| t.stat().unwrap().comm).collect();
threads.iter().find(|s| &**s == name).expect("thread should exist");

The TaskIterator is lazy

This means both that tasks that stop before you get to them in iteration will not be there, and that new tasks that are created after you start the iterator will appear.

let proc = Process::myself()?;

// Task iteration is lazy
let mut task_iter = proc.tasks()?.flatten().map(|t| t.stat().unwrap().comm);

let name = "testing:lazy";
let t = thread::Builder::new().name(name.to_string())
  .spawn(move || { // do work
  })?;

task_iter.find(|s| &**s == name).expect("thread should exist");

Tasks that stop while you’re iterating may or may not appear:

let name = "testing:stopped";
let t = thread::Builder::new().name(name.to_string())
  .spawn(move || { // do work
  })?;

let proc = Process::myself()?;

// Task iteration is lazy
let mut task_iter = proc.tasks()?.flatten().map(|t| t.stat().unwrap().comm);

t.join().unwrap();

// It's impossible to know if this is going to be gone
let _ = task_iter.find(|s| &**s == name).is_some();

impl Process

pub fn cgroups(&self) -> ProcResult<Vec<ProcessCgroup>>

Describes control groups to which the process with the corresponding PID belongs.

The displayed information differs for cgroupsversion 1 and version 2 hierarchies.

Trait Implementations

impl Clone for Process

fn clone(&self) -> Process

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Process

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.