How can I find why system can not run my applicati

问题:

I have a c++ program that run a command and pass some arguments to it. The code is as follow:

 int RunApplication(fs::path applicationPathName,std::string arguments)
 {
    std::string applicationShortPath=GetShortFileName(applicationPathName);
    std::string cmd="\""+applicationShortPath +"\"  "+ arguments+" >>log.txt 2>&1 \"";
    std::cout<<cmd<<std::endl;
    int result=std::system(cmd.c_str());
    return result;
 }

When I run system command, the cmd window appears shortly and then closes, but the result is 1 and the cmd was not run (the command should generate output which is not generated).

To check that the cmd is correct, I stopped the application just before system line and copy/ paste cmd content to a cmd window and it worked.

I am wondering how can I find why application is not run in system()?

the cmd has this value just before running it:

"D:/DEVELO~3/x64/Debug/enfuse.exe"  -w --hard-mask --exposure-weight=1 --saturation-weight=0.328 --contrast-weight=0.164 -o "C:/Users/m/AppData/Local/Temp/1.tif"  "C:/Users/m/AppData/Local/Temp/1.jpg" "C:/Users/m/AppData/Local/Temp/2.jpg"  >>log.txt 2>&1 "

How can I find why it is not working?

Is there any way that I set the system so it doesn't close cmd window so I can inspect it?

is there any better way to run a command on OS?

Does Boost has any solution for this?

Edit

After running it with cmd /k, I get this error message:

The input line is too long.

How can I fix it other than reducing cmd line?

回答1:

Use cmd /k to keep the terminal: http://ss64.com/nt/cmd.html

Or just spawn cmd.exe instead and inspect the environment, permissions, etc. You can manually paste that command to see whether it would work from that shell. If it does, you know that paths, permssions and environment are ok, so you have some other issue on your hands (argument escaping, character encoding issues)

回答2:

There are two different things here: if you have to start a suprocess, "system" is not the best way of doing it (better to use the proper API, like CreateProcess, or a multiplatform wrapper, but avoid to go through the command interpreter, to avoid to open to potential malware injection).

But in this case system() is probably the right way to go since you in fact need the command interpreter (you cannot manage things like >>log.txt 2>&1 with only a process creation.)

The problem looks like a failure in the called program: may be the path is not correct or some of the files it has to work with are not existent or accessible with appropriate-permission and so on.

One of the firt thing to do: open a command prompt and paste the string you posted, in there. Does it run? Does it say something about any error?

Another thing to check is how escape sequence are used in C++ literals: to get a '\', you need '\\' since the first is the escape for the second (like \n, or \t etc.). Although it seems not the case, here, it is one of the most common mistakes.

回答3:

• Check here How to execute a command and get output of command within C++ using POSIX?
• Boost.Process is not official yet http://www.highscore.de/boost/process/