genfile: implement the --set-time optionHEADmaster

* doc/genfile.texi: Document changes.
* tests/genfile.c: New options: --set-time and --no-dereference.

2 files changed, 87 insertions, 7 deletions

diff --git a/doc/genfile.texi b/doc/genfile.texi
index 17c97d2..1c3de81 100644
--- a/doc/genfile.texi
+++ b/doc/genfile.texi
@@ -14,7 +14,7 @@ the testsuite, hence its name. However, new operation modes were being
 implemented as the testsuite grew more sophisticated, and now
 @command{genfile} is a multi-purpose instrument.
 
-    There are three basic operation modes:
+    There are four basic operation modes:
 
 @table @asis
 @item File Generation
@@ -24,6 +24,10 @@ generates data files.
 @item File Status
     In this mode @command{genfile} displays status of specified files.
 
+@item Set File Time
+    Set last access and modification times of files given in the
+command line.
+
 @item Synchronous Execution.
     In this mode @command{genfile} executes the given program with
 @option{--checkpoint} option and executes a set of actions when
@@ -31,9 +35,10 @@ specified checkpoints are reached.
 @end table
 
 @menu
-* Generate Mode::     File Generation Mode.
-* Status Mode::       File Status Mode.
-* Exec Mode::         Synchronous Execution mode.
+* Generate Mode::       File Generation Mode.
+* Status Mode::         File Status Mode.
+* Set File Time::       Set File Time Mode.
+* Exec Mode::           Synchronous Execution Mode.
 @end menu
 
 @node Generate Mode
@@ -278,6 +283,34 @@ directory:
 genfile --stat=name,atime *
 @end smallexample
 
+   By default, @command{genfile} follows symbolic links and returns
+information about files pointed to by them.  To get information about
+the symlink files themselves, use the @option{--no-dereference}
+(@option{-h}) option.
+
+@node Set File Time
+@appendixsec Set File Time
+@cindex Set File Time Mode, @command{genfile}
+    This mode is requested by the @option{--set-time} (@option{-t})
+command line option.  In this mode @command{genfile} operates
+similarly to the @command{touch} command: for each file listed in the
+command line, it sets its access and modification times to the current
+timestamp or to the value given with the @option{--date} option.  The
+@option{--date} option takes a date specification in
+an almost arbitrary format as its argument (@pxref{Date input
+formats}), e.g.:
+
+@example
+genfile --set-time --date='2 days ago' a b c
+@end example
+
+    By default, @command{genfile} follows symbolic links and sets
+times of the file they point to.  This can be changed by supplying the
+@option{--no-dereference} (@option{-h}) option: if it is given,
+@command{genfile} will change access and modification times of the
+symbolic link itself.  Notice, that not all operating systems allow
+this.
+
 @node Exec Mode
 @appendixsec Exec Mode
 
@@ -346,6 +379,14 @@ option was given, in which case they are changed to the specified
 time. Argument to @option{--date} option is a date specification in
 an almost arbitrary format (@pxref{Date input formats}).
 
+@item -h
+@itemx --no-dereference
+    Modifies the action of the @option{--touch} option.  If both
+options are given and @var{file} argument to the @option{--touch}
+names a symbolic link, @command{genfile} will modify access and
+modification times of the symbolic link file itself, instead the
+file the symlink points to.
+
 @item --exec @var{command}
     Execute given shell command.
 
diff --git a/tests/genfile.c b/tests/genfile.c
index be4a2d3..0074c5c 100644
--- a/tests/genfile.c
+++ b/tests/genfile.c
@@ -77,7 +77,8 @@ enum genfile_mode
     mode_generate,
     mode_sparse,
     mode_stat,
-    mode_exec
+    mode_exec,
+    mode_set_times
   };
 
 enum genfile_mode mode = mode_generate;
@@ -106,6 +107,9 @@ int verbose;
 /* Quiet mode */
 int quiet;
 
+/* Don't dereference symlinks (for --stat) */
+int no_dereference_option;
+
 const char *argp_program_version = "genfile (" PACKAGE ") " VERSION;
 const char *argp_program_bug_address = "<" PACKAGE_BUGREPORT ">";
 static char doc[] = N_("genfile manipulates data files for GNU paxutils test suite.\n"
@@ -155,6 +159,14 @@ static struct argp_option options[] = {
    N_("Print contents of struct stat for each given file. Default FORMAT is: ")
    DEFAULT_STAT_FORMAT,
    GRP+1 },
+  {"no-dereference", 'h', NULL, 0,
+   N_("stat symbolic links instead of referenced files"),
+   GRP+1 },
+
+  {"set-times", 't', NULL, 0,
+   N_("Set access and modification times of the files to the time supplied"
+      " by --date option"),
+   GRP+1 },
 
 #undef GRP
 #define GRP 20
@@ -348,6 +360,14 @@ parse_opt (int key, char *arg, struct argp_state *state)
 	stat_format = arg;
       break;
 
+    case 't':
+      mode = mode_set_times;
+      break;
+
+    case 'h':
+      no_dereference_option = 1;
+      break;
+
     case 'r':
       mode = mode_exec;
       checkpoint_granularity = arg ? arg : "1";
@@ -647,7 +667,7 @@ print_stat (const char *name)
   char *fmt, *p;
   struct stat st;
 
-  if (stat (name, &st))
+  if ((no_dereference_option ? lstat : stat) (name, &st))
     {
       error (0, errno, _("stat(%s) failed"), name);
       return;
@@ -725,6 +745,17 @@ print_stat (const char *name)
   free (fmt);
 }
 
+void
+set_times (char const *name)
+{
+  struct timespec ts[2];
+
+  ts[0] = ts[1] = touch_time;
+  if (utimensat (AT_FDCWD, name, ts, no_dereference_option ? AT_SYMLINK_NOFOLLOW : 0) != 0)
+    {
+      error (EXIT_FAILURE, errno, _("cannot set time on `%s'"), name);
+    }
+}
 
 /* Exec Mode */
 
@@ -740,7 +771,7 @@ exec_checkpoint (struct action *p)
 	struct timespec ts[2];
 
 	ts[0] = ts[1] = p->ts;
-	if (utimensat (AT_FDCWD, p->name, ts, 0) != 0)
+	if (utimensat (AT_FDCWD, p->name, ts, no_dereference_option ? AT_SYMLINK_NOFOLLOW : 0) != 0)
 	  {
 	    error (0, errno, _("cannot set time on `%s'"), p->name);
 	    break;
@@ -987,6 +1018,14 @@ main (int argc, char **argv)
 	print_stat (*argv++);
       break;
 
+    case mode_set_times:
+      if (argc == 0)
+	error (EXIT_USAGE, 0, _("--set-times requires file names"));
+
+      while (argc--)
+	set_times (*argv++);
+      break;
+
     case mode_sparse:
       generate_sparse_file (argc, argv);
       verify_file (file_name);