请问如何用程序设置WINDOWS的环境变量

[bjxiaoye]

请问如何用程序设置WINDOWS的环境变量

[一个傻冒]

SetEnvironmentVariable

The SetEnvironmentVariable function sets the value of an environment variable for the current process.

LPTSTR lpszCurrentVariable;
BOOL fSuccess;

// Copy environment strings into an environment block.

lpszCurrentVariable = tchNewEnv;
if (lstrcpy(lpszCurrentVariable, "API=Win32") == NULL)
ErrorExit("lstrcpy failed");

lpszCurrentVariable += lstrlen(lpszCurrentVariable) + 1;
if (lstrcpy(lpszCurrentVariable, "OperatingSystem=Windows") == NULL)
ErrorExit("lstrcpy failed");

// Terminate the block with a NULL byte.

lpszCurrentVariable += lstrlen(lpszCurrentVariable) + 1;
*lpszCurrentVariable = '\0';

// Create the child process, specifying a new environment block.

fSuccess = CreateProcess(NULL, "childenv", NULL, NULL, TRUE, 0,
(LPVOID) tchNewEnv, // new environment block
NULL, &siStartInfo, &piProcInfo);

if (! fSuccess)
ErrorExit("CreateProcess failed");
If you want the child process to inherit most of the parent's environment with only a few changes, save the current values, make changes for the child process to inherit, create the child process, and then restore the saved values, as shown following.

LPTSTR lpszOldValue;
TCHAR tchBuf[BUFSIZE];
BOOL fSuccess;

// lpszOldValue gets current value of "varname", or NULL if "varname"
// environment variable does not exist. Set "varname" to new value,
// create child process, then use SetEnvironmentVariable to restore
// original value of "varname". If lpszOldValue is NULL, the "varname"
// variable will be deleted.

lpszOldValue = ((GetEnvironmentVariable("varname",
tchBuf, BUFSIZE) > 0) ? tchBuf : NULL);

// Set a value for the child process to inherit.

if (! SetEnvironmentVariable("varname", "newvalue"))
ErrorExit("SetEnvironmentVariable failed");

// Create a child process.

fSuccess = CreateProcess(NULL, "childenv", NULL, NULL, TRUE, 0,
NULL, // inherit parent's environment
NULL, &siStartInfo, &piProcInfo);
if (! fSuccess)
ErrorExit("CreateProcess failed");

// Restore the parent's environment.

if (! SetEnvironmentVariable("varname", lpszOldValue))
ErrorExit("SetEnvironmentVariable failed");