将CreateProcess与通过bat文件设置的环境变量一起使用

Question

I'm executing an external application using the CreateProcess function, in order which such application be executed I need run a .bat file before to set some environments variables. The issue is when i call CreateProcess to run the bat file and then execute CreateProcess again for run the external app the environment variables are not used. The question is how i can use the environment variables set in the bat file when I execute CreateProcess function the second time?

Answer 1

If the initial createprocess batch file is simply to setup the environment variables, create the enviornment variable block instead and pass it directly via the CreateProcess() call.

Some sample code is available here for getting/setting environment variables and for passing a block to CreateProcess() http://www.delphidabbler.com/articles?article=6

Answer 2

You can use CreateProcess() to run the OS's cmd.exe program to execute multiple commands at one time, eg:

TCHAR szCmd[(MAX_PATH * 3) + 16] = {0};
TCHAR szPathToCmdExe[MAX_PATH+1] = {0}
GetEnvironmentVariable(TEXT("COMSPEC"), szPathToCmdExe, MAX_PATH+1);
wsprintf(szCmd, TEXT("\"%s\" /C \"%s && %s\""), szPathToCmdExe, szPathToBat, szPathToProgram);
CreateProcess(NULL, szCmd, ...);

Answer 3

If you execute the other application from the batch file it would have those environment variables set. You could pass the executable name as a parameter to the batch file. When you set environment variables within the batch file, they only exist until that batch file exits.