putenv.cpp

QT4的utils库源码包.解压后运行./configure配置,然后make.使用时在.pro文件中加入两行:LIBS+=-L$$(CPPLIBS)-lutils及INCLUDEPATH+=$$(C

#include "putenv.h"

#include <QTextStream>
#include <QProcess>
#include <QList>
#include <QStringList>
#include <cstring>
#include <stdlib.h>

class EnvStrings : public QList<char*> {
    public:
    ~EnvStrings() {
        /* This works:  */
        int l = count(); 
        for (int i=0; i < l; ++i) {
            delete[] at(i);
        } 
        
        /* The below foreach() causes a segfault.
        foreach (char* ptr, *this) {
            delete[] ptr;
        }
		*/ /** In order to understand why, you need to know that a foreach
			always makes a copy of the collection.
			Since we are copying the object we are destroying, and copy needs
			to be destroyed too, we have infinite recursion, combined with
			repeated deletions the same memory. */


    }
};

void qstd::putenv(QString key, QString value) {
    static EnvStrings newEnv;
    QString str = QString("%1=%2").arg(key).arg(value);
    int len = str.length() + 1;
    char* charStar = new char[len+1];
    strncpy(charStar, str.toAscii(), len);
    newEnv << charStar;
    ::putenv(charStar); /* call Global version */
}