mueval: Safely evaluate Haskell expressions

[ bsd3, development, language, library, program ] [ Propose Tags ]

Mueval is a Haskell interpreter. It uses the GHC API to evaluate arbitrary Haskell expressions. Importantly, mueval takes many precautions to defang and avoid "evil" code. It uses resource limits, whitelisted modules, special Show instances for IO, threads, changes of directory, and so on to sandbox the Haskell code. (It is much like Lambdabot's famous evaluation functionality.)

Currently there is a major hole in Mueval: it is possible use a function without importing it, which allows the module whitelisting to be bypassed, and hence, unsafePerformIO and its various type-breaking friends can be used to do arbitrary things. Mueval uses a blacklist to avoid the most naive and obvious dangerous function imports, but this is a very weak mechanism and cannot be relied upon.

Until this hole is fixed, Mueval should *not* be used on potentially hostile input.

Mueval is currently POSIX-only.


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Versions [RSS] 0.2, 0.2.1, 0.3, 0.3.1, 0.4, 0.4.5, 0.4.6, 0.5, 0.5.1, 0.6, 0.6.1, 0.6.2, 0.6.3, 0.6.4, 0.7.0, 0.7.1, 0.8, 0.8.1, 0.8.2, 0.9, 0.9.1,,, 0.9.3, 0.9.4
Dependencies base, directory, hint (>=0.2.2), mtl, show, unix [details]
License BSD-3-Clause
Author Gwern
Maintainer Gwern <>
Category Development, Language
Home page
Uploaded by GwernBranwen at 2008-06-26T15:56:41Z
Distributions Arch:0.9.3, Debian:0.9.3, FreeBSD:, NixOS:0.9.4
Reverse Dependencies 5 direct, 1 indirect [details]
Executables mueval
Downloads 26673 total (77 in the last 30 days)
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Status Docs uploaded by user
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