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System.Process.readProcess: incorrect documentation of return value

Originally reported at Haskell Platform bug tracker:


The System.Process docs here:

http://haskell.org/ghc/docs/6.12.2/html/libraries/process-1.0.1.2/System-Process.html#v%3AreadProcess

describes the return value as:

returns either the output string, or, in the case of non-zero exit status, an error code, and any output.

and the given example output is:

Right "Thu Feb 7 10:03:39 PST 2008\n"

This suggests that the return value looks like:

IO (Either ? String)

But the return type is shown (in that same documentation, and in ghci 6.12.3) as IO String, and my own experimentation shows no "Right" being returned in the case of a successful operation - instead I get only the String containing the program output, not wrapped.

Perhaps this is historic.

Trac metadata
Trac field Value
Version 6.12.3
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component libraries/process
Test case
Differential revisions
BlockedBy
Related
Blocking
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Operating system
Architecture
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