process

Process libraries

Version on this page:1.6.9.0
LTS Haskell 24.0:1.6.25.0
Stackage Nightly 2025-07-14:1.6.25.0
Latest on Hackage:1.6.26.1

See all snapshots process appears in

BSD-3-Clause licensed
Maintained by [email protected]
This version can be pinned in stack with:process-1.6.9.0@sha256:0cafe6e1313790863bd81cf40563baf5feea9ca2957e79a4d92bacfcc455604a,2468

Module documentation for 1.6.9.0

This package contains libraries for dealing with system processes.

The typed-process package is a more recent take on a process API, which uses this package internally. It features better binary support, easier concurrency, and a more composable API. You can read more about it at https://github.com/fpco/typed-process/#readme.

Changes

Changelog for process package

1.6.9 May 2020

  • Windows: Fix buffer size of QueryInformationJobObject request #176

1.6.8.2 March 2020

  • Fix another process wait bug on Windows.

1.6.8.1 March 2020

  • Fix a few warnings on Windows.

1.6.8.0 February 2020

  • Fix several bugs on Windows where use of process jobs would result in the process being prematurely terminated. See #168.

1.6.7.0 November 2019

  • Fix a race condition on Windows that happens when you use process jobs and one of the child processes terminates but doesn’t release its resources immediately. Control returns to the caller too soon in this scenario. See #159

1.6.6.0 October 2019

  • Fix a potential privilege escalation issue (or, more precisely, privileges not being dropped when this was the user’s intent) where the groups of the spawning process’s user would be incorrectly retained due to a missing call to initgroups [#149].
  • Bug fix: Prevent stripping undecodable bytes from environment variables when in a non-unicode locale. #152
  • Expose runInteractiveProcess_lock in System.Process.Internals #154

1.6.5.1 June 2019

  • Version bound bumps
  • Slightly nicer error messages for internal errors

1.6.5.0 December 2018

  • Bug fix: On Windows ignore ERROR_ACCESS_DENIED for TerminateProcess() if the process did terminate #110
  • Improve documentation of the NoStream data constructor

1.6.4.0 July 2018

  • Bug fix: Don’t leak pipes on failure #122
  • Expose cleanupProcess from System.Process #130
  • Drop support for GHC before 7.10.3

1.6.3.0 January 2018

  • Added getPid and export of platform specific Pid type #109

1.6.2.0 October 2017

  • Allow async exceptions to be delivered to masked thread calling waitForProcess #101
  • Update Win32 package version to 2.6.x

1.6.1.0 July 2017

  • Expose CGid, GroupID, and UserID from System.Process.Internals #90 #91

1.6.0.0 February 2017

  • Fix: waitForProcess race condition #46 #58

1.5.0.0 February 2017

  • Bug fix: Don’t close already closed pipes #81
  • Relax version bounds of Win32 to allow 2.5.
  • Add support for monitoring process tree for termination with the parameter use_process_jobs in CreateProcess on Windows. Also added a function terminateJob to kill entire process tree.

1.4.3.0 December 2016

  • New exposed withCreateProcess
  • Derive Show and Eq for CreateProcess, CmdSpec, and StdStream

1.4.2.0 January 2016

  • Added createPipeFD #52
    • New function createPipeFD added which returns a POSIX File Descriptor (CInt) instead of a GHC Handle to a pipe

1.4.1.0 November 2015

  • Use less CPP #47
    • Refactor to have separate Windows and POSIX modules internally
    • Remove the broken non-GHC code paths

1.4.0.0 November 2015

  • Added child_user and child_group to CreateProcess for unix. #45

1.3.0.0 August 2015

  • Add StdStream(NoStream) to have standard handles closed. #13
  • Support for Windows DETACHED_PROCESS and setsid #32
  • Support for Windows CREATE_NEW_CONSOLE #38

1.2.3.0 March 2015

1.2.2.0 Jan 2015

  • Fix delegated CTRL-C handling in createProcess in case of failed process creation. See issue #15 for more details.

  • waitpid on child PID after pre-exec failure in child to prevent zombies. See also issue #14.

1.2.1.0 Dec 2014

  • Add support for base-4.8.0.0

  • Remove Hugs98 specific code

  • New IsString CmdSpec instance

  • Expose documentation for System.Process.Internals

  • With GHC 7.10, System.Cmd and System.Process are now Safe (when compiled with older GHC versions they are just Trustworthy)

  • Expose createProcess_ function, and document behavior of UseHandle for createProcess. See issue #2.

  • New System.Process.createPipe operation. See also GHC #8943

1.2.0.0 Dec 2013

  • Update to Cabal 1.10 format
  • Remove NHC specific code
  • Add support for base-4.7.0.0
  • Improve showCommandForUser to reduce redundant quoting
  • New functions callProcess, callCommand, spawnProcess and spawnCommand
  • Implement WCE handling according to http://www.cons.org/cracauer/sigint.html
  • New delegate_ctlc field in CreateProcess for WCE handling
  • Use ExitFailure (-signum) on Unix when a proc is terminated due to a signal.
  • Deprecate module System.Cmd
  • On non-Windows, the child thread now comunicates any errors back to the parent thread via pipes.
  • Fix deadlocks in readProcess and readProcessWithExitCode