如何實(shí)現(xiàn)程序查看系統(tǒng)環(huán)境變量
[ljl@dhcp-8116-1 uc]$ env
C++程序:
#include <iostream>
using namespace std;
int main(int args,char** argv,char** env)
{
while(env&&*env)
{
cout << *env <<endl;
++env;
}
return 0;
}
使用main函數(shù)的重載.
char** env 是一個(gè)二維數(shù)組指針,可以遍利二維數(shù)組得到環(huán)境變量.
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#include <iostream>
using namespace std;
const unsigned size = 5;
void printInfo(char** env)
{
while(env && *env)
{
cout << *env << endl;
env++;
}
}
void init(int** data)
{
while(data && *data)
{
for(int i = 0; i < 5; i++)
(*data)[i] = i;
data++;
}
}
void printInfo(int** point)
{
while(point && *point)
{
for(int i = 0; i < 5; i++)
{
cout << (*point)[i] << "\t";
}
cout << endl;
point++;
}
}
int main()
{
char p[4][15] = {{"hello"},{"world"},{"my"},{"girl"}};
char* point[5];
for(int i = 0; i < sizeof(p)/sizeof(p[0]); i++)
{
point[i] = p[i];
}
point[4] = NULL;
printInfo(point);
int* piArr[size];
for(int i = 0; i < size-1; i++)
{
int* pi = new int[5];
piArr[i] = pi;
}
piArr[size-1] = NULL;
init(piArr);
printInfo(piArr);
return 0;
}
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