Article ID: 235601 - Last Review: September 6, 2005 - Revision: 3.0

BUG: Putenv() function may cause memory leak when the function is used to remove or to replace an environment variable in Visual C++

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This article was previously published under Q235601

SYMPTOMS

A memory leak results from calls to putenv in the following circumstances:

An environment variable is removed.
An environment variable is replaced.
The input parameter does not contain an equal sign (=) character.

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STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section.

This problem was corrected in Microsoft Visual C++ .NET.

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MORE INFORMATION

Steps to Reproduce Behavior

The following sample code demonstrates the types of calls that will cause a memory leak.

#include <stdlib.h>

void main()
{
    for (;;) {

        putenv( "MYVAR1=mystring" ); // Replaces string MYVAR1
                                     // after first iteration.

        putenv( "MYVAR2=mystring" ); // Creates and removes MYVAR2.
        putenv( "MYVAR2=" );         // 

        putenv( "MYVAR3" );          // Invalid string missing "=".
    }
}

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