c - 生成守护函数和信号处理程序

Question

我想生成一个守护进程并应用信号处理程序并将它们记录在文件中。我无法在文件中记录信号处理程序。另外我不确定这些信号处理程序是否正常工作......如何检查它们。请帮忙

/* A signal handler */

void signal_handler(int signal)
{
    printf("Caught signal %d\t", signal);
    if (signal == SIGINT)
    printf("Interrupt (Ctrl-C)");
    else if (signal == SIGQUIT)
    {
    printf("QUIT");
    exit(0);
    }
    else if (signal == SIGABRT)
    {
    printf("Process Aborted");
    exit(0);
    }
    else if (signal == SIGTRAP)
    printf("Trace/breakpoint trap");
    else if (signal == SIGKILL)
    {
    printf("Kill");
    exit(0);
    }
    else if (signal == SIGTERM)
    printf("Termination");
    else if (signal == SIGCONT)
    printf("Continue if stopped");
    else if (signal == SIGTSTP)
    printf("Pause the execution");
    printf("\n");
}

Here is the main function

FILE *fp= NULL; 
fp = fopen ("Log.txt", "w+");
do
{
    daemon(1, 1);// fork to a background daemon process 
    //printf("daemon is not working");
    printf("daemon-ed \n ");
    /* Registering signal handlers */
    signal(SIGINT, signal_handler);
    signal(SIGQUIT, signal_handler); // Set signal_handler() as the
    signal(SIGABRT, signal_handler); // signal handler for these
    signal(SIGTRAP, signal_handler); // signals.
    signal(SIGKILL, signal_handler);
    signal(SIGTERM, signal_handler);
    signal(SIGCONT, signal_handler);
    signal(SIGTSTP, signal_handler);

    fprintf(fp, "%s", signal);
    fflush(fp);
    // Implement and call some function that does core work for this daemon.

    fclose(fp);
}while(-1);


 return 0;

Answer 1

fprintf() 到文件确实非常简单下面的示例来自http://www.cplusplus.com/reference/cstdio/fprintf/

您需要文件指针，您可以在 main FILE * pFile 中声明它，例如

然后使用fopen给pFile值

之后您可以使用 fprintf 写入文件

/* fprintf example */
#include <stdio.h>

int main ()
{
   FILE * pFile;
   int n;
   char name [100];

   pFile = fopen ("myfile.txt","w");
   for (n=0 ; n<3 ; n++)
   {
     puts ("please, enter a name: ");
     gets (name);
     fprintf (pFile, "Name %d [%-10.10s]\n",n,name);
   }
   fclose (pFile);

   return 0;
}