tty/demo_SIGWINCH.c

This is tty/demo_SIGWINCH.c (Listing 62-5, page 1320), an example program file from the book The Linux Programming Interface.

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+/* demo_SIGWINCH.c
+
+   Demonstrate the generation of the SIGWINCH signal. A handler for SIGWINCH
+   allows the program to discover terminal window size changes; when that
+   signal is generated, the program displays the new terminal window size.
+*/
 #include <signal.h>
 #include <termios.h>
 #include <sys/ioctl.h>
 #include "tlpi_hdr.h"
 
 static void
 sigwinchHandler(int sig)
 {
 }
 
 int
 main(int argc, char *argv[])
 {
     struct winsize ws;
     struct sigaction sa;
 
     sigemptyset(&sa.sa_mask);
     sa.sa_flags = 0;
     sa.sa_handler = sigwinchHandler;
     if (sigaction(SIGWINCH, &sa, NULL) == -1)
         errExit("sigaction");
 
     for (;;) {
         pause();                        /* Wait for SIGWINCH signal */
 
         if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == -1)
             errExit("ioctl");
         printf("Caught SIGWINCH, new window size: "
                 "%d rows * %d columns\n", ws.ws_row, ws.ws_col);
     }
 }