A-M baby

Task/File-modification-time/C/file-modification-time-1.c

@@ -0,0 +1,27 @@
+#include <sys/stat.h>
+#include <stdio.h>
+#include <time.h>
+#include <utime.h>
+
+const char *filename = "input.txt";
+
+int main() {
+  struct stat foo;
+  time_t mtime;
+  struct utimbuf new_times;
+
+  if (stat(filename, &foo) < 0) {
+    perror(filename);
+    return 1;
+  }
+  mtime = foo.st_mtime; /* seconds since the epoch */
+
+  new_times.actime = foo.st_atime; /* keep atime unchanged */
+  new_times.modtime = time(NULL);    /* set mtime to current time */
+  if (utime(filename, &new_times) < 0) {
+    perror(filename);
+    return 1;
+  }
+
+  return 0;
+}

Task/File-modification-time/C/file-modification-time-2.c

@@ -0,0 +1,24 @@
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <err.h>
+
+const char *filename = "input.txt";
+
+int main() {
+  struct stat foo;
+  struct timeval new_times[2];
+
+  if (stat(filename, &foo) < 0)
+    err(1, "%s", filename);
+
+  /* keep atime unchanged */
+  TIMESPEC_TO_TIMEVAL(&new_times[0], &foo.st_atim);
+
+  /* set mtime to current time */
+  gettimeofday(&new_times[1], NULL);
+
+  if (utimes(filename, new_times) < 0)
+    err(1, "%s", filename);
+
+  return 0;
+}

Task/File-modification-time/C/file-modification-time-3.c

@@ -0,0 +1,30 @@
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <time.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+const char *filename = "input.txt";
+
+int main() {
+  struct stat foo;
+  struct timespec new_times[2];
+
+  if (stat(filename, &foo) < 0) {
+    perror(filename);
+    return 1;
+  }
+
+  /* keep atime unchanged */
+  new_times[0] = foo.st_atim;
+
+  /* set mtime to current time */
+  clock_gettime(CLOCK_REALTIME, &new_times[1]);
+
+  if (utimensat(AT_FDCWD, filename, new_times, 0) < 0) {
+    perror(filename);
+    return 1;
+  }
+
+  return 0;
+}

Task/File-modification-time/C/file-modification-time-4.c

@@ -0,0 +1,107 @@
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+/* Print "message: last Win32 error" to stderr. */
+void
+oops(const wchar_t *message)
+{
+	wchar_t *buf;
+	DWORD error;
+
+	buf = NULL;
+	error = GetLastError();
+	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+	    FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+	    NULL, error, 0, (wchar_t *)&buf, 0, NULL);
+
+	if (buf) {
+		fwprintf(stderr, L"%ls: %ls", message, buf);
+		LocalFree(buf);
+	} else {
+		/* FormatMessageW failed. */
+		fwprintf(stderr, L"%ls: unknown error 0x%x\n",
+		    message, error);
+	}
+}
+
+int
+setmodtime(const wchar_t *path)
+{
+	FILETIME modtime;
+	SYSTEMTIME st;
+	HANDLE fh;
+	wchar_t date[80], time[80];
+
+	fh = CreateFileW(path, GENERIC_READ | FILE_WRITE_ATTRIBUTES,
+	    0, NULL, OPEN_EXISTING, 0, NULL);
+	if (fh == INVALID_HANDLE_VALUE) {
+		oops(path);
+		return 1;
+	}
+
+	/*
+	 * Use GetFileTime() to get the file modification time.
+	 */
+	if (GetFileTime(fh, NULL, NULL, &modtime) == 0)
+		goto fail;
+	FileTimeToSystemTime(&modtime, &st);
+	if (GetDateFormatW(LOCALE_USER_DEFAULT, DATE_LONGDATE, &st, NULL,
+	    date, sizeof date / sizeof date[0]) == 0 ||
+	    GetTimeFormatW(LOCALE_USER_DEFAULT, 0, &st, NULL,
+	    time, sizeof time / sizeof time[0]) == 0)
+		goto fail;
+	wprintf(L"%ls: Last modified at %s at %s (UTC).\n",
+	    path, date, time);
+
+	/*
+	 * Use SetFileTime() to change the file modification time
+	 * to the current time.
+	 */
+	GetSystemTime(&st);
+	if (GetDateFormatW(LOCALE_USER_DEFAULT, DATE_LONGDATE, &st, NULL,
+	    date, sizeof date / sizeof date[0]) == 0 ||
+	    GetTimeFormatW(LOCALE_USER_DEFAULT, 0, &st, NULL,
+	    time, sizeof time / sizeof time[0]) == 0)
+		goto fail;
+	SystemTimeToFileTime(&st, &modtime);
+	if (SetFileTime(fh, NULL, NULL, &modtime) == 0)
+		goto fail;
+	wprintf(L"%ls: Changed to %s at %s (UTC).\n", path, date, time);
+
+	CloseHandle(fh);
+	return 0;
+
+fail:
+	oops(path);
+	CloseHandle(fh);
+	return 1;
+}
+
+/*
+ * Show the file modification time, and change it to the current time.
+ */
+int
+main()
+{
+	int argc, i, r;
+	wchar_t **argv;
+
+	/* MinGW never provides wmain(argc, argv). */
+	argv = CommandLineToArgvW(GetCommandLineW(), &argc);
+	if (argv == NULL) {
+		oops(L"CommandLineToArgvW");
+		exit(1);
+	}
+
+	if (argc < 2) {
+		fwprintf(stderr, L"usage: %ls file...\n", argv[0]);
+		exit(1);
+	}
+
+	r = 0;
+	for (i = 1; argv[i] != NULL; i++)
+		if (setmodtime(argv[i])) r = 1;
+	return r;
+}