How to print your log in VxWorks 6.x

Issue:

For embedded software developer using printf is the most used debug method on target. But in vxworks6.x, it start to change because the default stdout/stderr is redirected. If you connect to device by shell/telnet, printf in the code will not put to the stdout/stderr in the current shell.

Solution:

You can put a the following code in the debug version. Once you have connect to target by shell/telnet, call the function to redirect some task /all task io to the current shell.

void ioRedirect(void)
{
    int shellTid = 0;
    int shellOpFd = 0;
    int globalStdFd = 0;

    shellTid = taskIdSelf();
    shellOpFd = ioTaskStdGet(shellTid, 1);
    globalStdFd = ioGlobalStdGet(1);

    (void)logMsg("LM:Initial task output.shellFd %d, GlobalFd %d.\n", shellOpFd, globalStdFd, 0, 0, 0, 0);

    printf("p:Initial task output.shellFd %d, GlobalFd %d.\n", shellOpFd, globalStdFd);

    /*you can specify the task who need printf*/
    /*ioTaskStdSet(GSETaskId,1,shellOpFd);
    ioTaskStdSet(mstEvtId,1,shellOpFd);*/

    /*or set the global io*/
    ioGlobalStdSet(1, shellOpFd);
    globalStdFd = ioGlobalStdGet(1);

    logMsg("LM:Initial task output.shellFd %d, GlobalFd change to %d.\n", shellOpFd, globalStdFd, 0, 0, 0, 0);

    printf("p:Initial task output to globalStdFd %d.\n", globalStdFd);
}