init

sigcat.c

@@ -0,0 +1,52 @@
+#include "sigcat.h"
+
+void setup_default_handlers(void) {
+    struct sigaction sa;
+    memset(&sa, 0, sizeof(sa));
+    sa.sa_handler = default_signal_handler;
+    sa.sa_flags = SA_RESTART;
+
+    for (int i = SIGMIN; i <= SIGMAX; i++) {
+        // Cannot process SIGKILL or SIGSTOP
+        if (i == SIGKILL || i == SIGSTOP) {
+            continue;
+        }
+
+        sigaction(i, &sa, 0);
+    }
+}
+
+void default_signal_handler(int s) {
+    fprintf(outputStream, "sigcat received %s\n", strsignal(s));
+    fflush(outputStream);
+
+    if (s == SIGUSR1 || s == SIGUSR2) {
+        usr_signal_handler(s);
+    }
+}
+
+void usr_signal_handler(int s) {
+    if (s == SIGUSR1) {
+        outputStream = stdout;
+    } else if (s == SIGUSR2) {
+        outputStream = stderr;
+    }
+}
+
+int main(int argc, char *argv[]) {
+    // Defined in header
+    outputStream = stdout;
+
+    setup_default_handlers();
+
+    // Forever loop input until recieve EOF
+    char *line;
+    while ((line = read_line(stdin)) != NULL) {
+        strcat(line, "\n");
+        fprintf(outputStream, line);
+        fflush(outputStream);
+        free(line);
+    }
+
+    return 0;
+}