init commit

3sem/seminars/l8/01.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <errno.h>
+
+void
+str_to_ll(char *str, long long *num)
+{
+    errno = 0;
+    char *endptr;
+    *num = strtoll(str, &endptr, 10);
+
+    if (*endptr || errno || endptr == str) {
+        fprintf(stderr, "Invalid number: %s\n", str);
+        exit(1); // TODO: по-хорошему заменить на внешний обработчик ошибок
+    }
+
+    return;
+}
+
+void
+make_proc(int deepth, int max_deepth)
+{
+    if (deepth == max_deepth) {
+        return;
+    }
+
+    printf("Deepth: %d\n", deepth);
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        fprintf(stderr, "Fork failed\n");
+        exit(1);
+    } else if (pid == 0) {
+        make_proc(deepth + 1, max_deepth);
+        exit(0);
+    } else {
+        wait(NULL);
+    }
+
+    return;
+}
+
+int
+main(int argc, char *argv[])
+{
+    if (argc != 2) {
+        fprintf(stderr, "Usage: %s <deepth>\n", argv[0]);
+        return 1;
+    }
+
+    long long deepth;
+    str_to_ll(argv[1], &deepth);
+    make_proc(0, deepth);
+
+    return 0;
+}