init commit

3sem/seminars/l6/01.c

@@ -0,0 +1,50 @@
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/file.h>
+#include <sys/types.h>
+#include <string.h>
+#include <dirent.h>
+#include <linux/limits.h>
+
+struct Files
+{
+    char *pathname;
+    __ino_t st_ino;
+    __dev_t st_dev;
+};
+
+int
+main(int argc, char **argv)
+{
+    struct stat st;
+    if (lstat(".", &st) == -1) {
+        printf("stat error\n");
+        return 1;
+    }
+
+    DIR *dir = opendir("..");
+    struct dirent *de;
+    while ((de = readdir(dir))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
+            continue;
+        }
+
+        struct stat sttmp;
+
+        char buf[PATH_MAX];
+        snprintf(buf, PATH_MAX, "%s/%s", "..", de->d_name);
+        if (lstat(buf, &sttmp) == -1) {
+            printf("lstat error\n");
+            return 1;
+        }
+        printf("%s\n", de->d_name);
+        if (sttmp.st_dev == st.st_dev && sttmp.st_ino == st.st_ino) {
+            printf("%s\n", de->d_name);
+        }
+    }
+
+    return 0;
+}

3sem/seminars/l6/02.c

@@ -0,0 +1,33 @@
+#include <time.h>
+#include <stdio.h>
+
+void
+f(int *y, int *m, int *d, int offset)
+{ // offset in seconds
+    struct tm t = {0};
+    // struct tm* tptr = calloc(1, sizeof(struct tm));
+    t.tm_isdst = -1;
+    t.tm_year = *y - 1900;
+    t.tm_mon = *m - 1;
+    t.tm_mday = *d;
+    time_t time = mktime(&t);
+    time += offset;
+    localtime_r(&time, &t);
+    *y = t.tm_year + 1900;
+    *m = t.tm_mon + 1;
+    *d = t.tm_mday;
+
+    return;
+}
+
+int
+main(void)
+{
+    int y = 2021;
+    int m = 1;
+    int d = 1;
+    f(&y, &m, &d, 65 * 60 * 60 * 24);
+    printf("%d-%d-%d\n", y, m, d);
+
+    return 0;
+}

3sem/seminars/l6/03.c

@@ -0,0 +1,45 @@
+#include <time.h>
+#include <stdio.h>
+#include <stdlib.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;
+}
+
+int
+main(int argc, char **argv)
+{
+    long long year, day, dw, res = 0;
+    str_to_ll(argv[1], &year);
+    str_to_ll(argv[2], &day);
+    str_to_ll(argv[3], &dw);
+
+    struct tm t = {0};
+    t.tm_isdst = -1;
+    t.tm_mday = 1;
+    t.tm_year = year - 1900;
+
+    while (t.tm_year == year - 1900) {
+        mktime(&t);
+        if (t.tm_mday == day && dw == t.tm_wday) {
+            res++;
+        }
+        t.tm_mday++;
+    }
+
+    printf("%d\n", (int) res);
+
+    return 0;
+}

3sem/seminars/l6/04.c

@@ -0,0 +1,47 @@
+#include <time.h>
+#include <stdio.h>
+#include <stdlib.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;
+}
+
+int
+main(int argc, char **argv)
+{
+    long long year, mth, res = 0;
+    str_to_ll(argv[1], &year);
+    str_to_ll(argv[2], &mth);
+
+    struct tm t = {0};
+    t.tm_isdst = -1;
+    t.tm_mday = 1;
+    t.tm_mon = mth - 1;
+    t.tm_year = year - 1900;
+
+    while (t.tm_mon == mth - 1) {
+        if (t.tm_wday > 0 && t.tm_wday < 5) {
+            res += 8;
+        } else if (t.tm_wday == 5) {
+            res += 6;
+        }
+        t.tm_mday++;
+        mktime(&t);
+    }
+
+    printf("%d\n", (int) res);
+
+    return 0;
+}