Home / server / Questions / 315077
In Process
Daniel C. Sobral
Asked: 2011-09-24 20:42:18 +0800 CST

Is there a Windows CMD equivalent of Unix shell's exec?

  • 772

Is there any equivalent in Windows to Unix Shell's "exec"? Basically, I need to avoid forking a new process, so that input/output pipes are preserved, as well as process id.

Edit:

So, here's my problem. I have a process A that starts a script, and this script ends by executing a process B. I need for A to get all of B's output, as well as be able to kill B by killing the process it has spawned (the script).

On Unix, executing B with exec does that job.

windows shell windows-command-prompt

4 Answers

  1. AFAIK there isn't. Windows lacks execv() which is how bash exec does it. call works for calling batch files (easy, just interpret the file in the current interpreter, similar to bash's . command) but not for exes.

    This makes it impossible to write one-liner wrapper scripts for scripts in any language on Windows. You'll always get that "Terminate batch job?" crap on Ctrl+C and killing the batch process (not with Ctrl+C, from task manager say) won't kill the child process. I'm now looking for a C template file to do this wrapping.

    UPDATE: Windows does have _execv() in its POSIX compatibility layer in MSVCRT, but AFAIK (haven't tested it) it's just a wrapper around CreateProcess so it will always create a new process, it cannot replace the current process.

    • 11

  2. I think call does what you want, but I'm not 100% sure.

    • 2

  3. You can construct a dynamic batch command and execute it based on the output of previous operations. I'm not sure this would be a solution in your case, but the following code works just fine.

    SET yourDynamicCommand=SET var=1
%yourDynamicCommand%
ECHO var's value is %var%
    • 0
    • Execute batch-files: call
    • Execute exe-files: No command needed, call it directly by /path/to/exe/something.exe
    • -1