init commit

3sem/seminars/l8/03.c

@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <string.h>
+#include <linux/limits.h>
+#include <sys/mman.h>
+#include <stdint.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;
+}
+
+int
+main(int argc, char *argv[])
+{
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <deepth> <file>\n", argv[0]);
+        return 1;
+    }
+
+    long long deepth;
+    str_to_ll(argv[1], &deepth);
+
+    truncate(argv[2], sizeof(int) * deepth);
+    int fd = open(argv[2], O_CREAT | O_RDWR, 0666);
+    int *addr = mmap(NULL, sizeof(int) * deepth, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+
+    for (int i = 1; i <= deepth; i++) {
+        if (fork() == 0) {
+            addr[deepth - i] = i;
+
+            return 0;
+        }
+    }
+
+    // for (int i = 1; i <= deepth; i++) {
+    //     wait(NULL);
+    // }
+
+    while (wait(NULL) != -1)
+        ;
+
+    munmap(addr, sizeof(int) * argc);
+
+    return 0;
+}