[Fwd: Re: Patch for touch to make it have a -p option, similar to mkdir]

[Marc Abramowitz]

Just curious if there are any comments on how to improve this patch, or 
is it just a bad idea to add this kind of functionality to a simple tool 
like touch?

-Marc

-------- Original Message --------
Subject:        Re: Patch for touch to make it have a -p option, similar to 
mkdir
Date:   Thu, 28 Dec 2006 15:40:30 -0800 (PST)
From:   Marc Abramowitz <address@hidden>
To:     Marc Abramowitz <address@hidden>, address@hidden



Actually, the patch that I just posted is incorrect, because it didn't 
actually add a -p option and did that behavior always. Here's a revised 
patch with the -p option added:

--- coreutils-6.7.orig/src/touch.c      2006-10-22 09:54:15.000000000 -0700
+++ coreutils-6.7/src/touch.c   2006-12-28 15:35:28.000000000 -0800
@@ -34,6 +34,8 @@
#include "safe-read.h"
#include "stat-time.h"
#include "utimens.h"
+#include "savewd.h"
+#include "mkdir-p.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "touch"
@@ -112,6 +114,62 @@
    error (EXIT_FAILURE, 0, _("invalid date format %s"), quote 
(flex_date));
}

+/* <hack
+   comment="Copied from mkdir.c; move to lib?"
+   date="2006-12-28"
+   author="Marc Abramowitz">
+ */
+
+/* Options passed to subsidiary functions.  */
+struct mkdir_options
+{
+  /* Function to make an ancestor, or NULL if ancestors should not be
+     made.  */
+  int (*make_ancestor_function) (char const *, char const *, void *);
+
+  /* Mode for ancestor directory.  */
+  mode_t ancestor_mode;
+
+  /* Mode for directory itself.  */
+  mode_t mode;
+
+  /* File mode bits affected by MODE.  */
+  mode_t mode_bits;
+
+  /* If not null, format to use when reporting newly made directories.  */
+  char const *created_directory_format;
+};
+
+static struct mkdir_options global_mkdir_options;
+
+static void
+announce_mkdir (char const *dir, void *options)
+{
+  struct mkdir_options const *o = options;
+  if (o->created_directory_format)
+    error (0, 0, o->created_directory_format, quote (dir));
+}
+
+/* Make ancestor directory DIR, whose last component is COMPONENT,
+   with options OPTIONS.  Assume the working directory is COMPONENT's
+   parent.  Return 0 if successful and the resulting directory is
+   readable, 1 if successful but the resulting directory is not
+   readable, -1 (setting errno) otherwise.  */
+static int
+make_ancestor (char const *dir, char const *component, void *options)
+{
+  struct mkdir_options const *o = options;
+  int r = mkdir (component, o->ancestor_mode);
+  if (r == 0)
+    {
+      r = ! (o->ancestor_mode & S_IRUSR);
+      announce_mkdir (dir, options);
+    }
+  return r;
+}
+
+/* </hack> */
+
/* Update the time of file FILE according to the options given.
   Return true if successful.  */

@@ -129,6 +187,18 @@
    fd = STDOUT_FILENO;
  else if (! no_create)
    {
+      {
+        char *dir = dir_name (file);
+        struct savewd wd;
+        savewd_init (&wd);
+        void *make_ancestor_function = 
global_mkdir_options.make_ancestor_function;
+        mode_t mode = global_mkdir_options.mode;
+        mode_t mode_bits = global_mkdir_options.mode_bits;
+        make_dir_parents (dir, &wd, make_ancestor_function, 
&global_mkdir_options,
+                          mode, announce_mkdir,
+                          mode_bits, (uid_t) -1, (gid_t) -1, true);
+      }
+         
      /* Try to open FILE, creating it if necessary.  */
      fd = fd_reopen (STDIN_FILENO, file,
                     O_WRONLY | O_CREAT | O_NONBLOCK | O_NOCTTY,
@@ -246,6 +316,7 @@
  -m                     change only the modification time\n\
"), stdout);
      fputs (_("\
+  -p, --parents          no error if existing, make parent directories 
as needed\n\
  -r, --reference=FILE   use this file's times instead of current time\n\
  -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current 
time\n\
  --time=WORD            change the specified time:\n\
@@ -272,6 +343,10 @@
  bool date_set = false;
  bool ok = true;
  char const *flex_date = NULL;
+  global_mkdir_options.make_ancestor_function = NULL;
+  global_mkdir_options.mode = S_IRWXUGO;
+  global_mkdir_options.mode_bits = 0;
+  global_mkdir_options.created_directory_format = NULL;

  initialize_main (&argc, &argv);
  program_name = argv[0];
@@ -284,7 +359,7 @@
  change_times = 0;
  no_create = use_ref = false;

-  while ((c = getopt_long (argc, argv, "acd:fmr:t:", longopts, NULL)) 
!= -1)
+  while ((c = getopt_long (argc, argv, "acd:fmpr:t:", longopts, NULL)) 
!= -1)
    {
      switch (c)
       {
@@ -307,6 +382,12 @@
         change_times |= CH_MTIME;
         break;

+        case 'p':
+          global_mkdir_options.make_ancestor_function = make_ancestor;
+          mode_t umask_value = umask (0);
+          global_mkdir_options.ancestor_mode = (S_IRWXUGO & 
~umask_value) | (S_IWUSR | S_IXUSR);
+          break;
+
       case 'r':
         use_ref = true;
         ref_file = optarg;


*/Marc Abramowitz <address@hidden>/* wrote:

   The other day I realized that often when I'm using touch, I'd like
   it to have the ability to create ancestor directories that don't
   exist, a la mkdir -p. I quickly hacked together a shell script to do
   what I want:
   http://marc.abramowitz.info/archives/2006/12/22/adding-a-p-option-to-touch/

   Then I thought that this might be a generally useful extension to
   touch, so I thought I'd take a stab at adding it to touch. Here it is:

   --- coreutils-6.7.orig/src/touch.c 2006-10-22 09:54:15.000000000 -0700
   +++ coreutils-6.7/src/touch.c 2006-12-28 13:45:22.000000000 -0800
   @@ -34,6 +34,8 @@
    #include "safe-read.h"
    #include "stat-time.h"
    #include "utimens.h"
   +#include "savewd.h"
   +#include "mkdir-p.h"
    
    /* The official name of this program (e.g., no `g' prefix).  */
    #define PROGRAM_NAME "touch"
   @@ -112,6 +114,60 @@
        error (EXIT_FAILURE, 0, _("invalid date format %s"), quote
   (flex_date));
    }
    
   +/* <hack
   +   comment="Copied from mkdir.c; move to lib?"
   +   date="2006-12-28"
   +   author="Marc Abramowitz">
   + */
   +
   +/* Options passed to subsidiary functions.  */
   +struct mkdir_options
   +{
   +  /* Function to make an ancestor, or NULL if ancestors should not be
   +     made.  */
   +  int (*make_ancestor_function) (char const *, char const *, void *);
   +
   +  /* Mode for ancestor directory.  */
   +  mode_t ancestor_mode;
   +
   +  /* Mode for directory itself.  */
   +  mode_t mode;
   +
   +  /* File mode bits affected by MODE.  */
   +  mode_t mode_bits;
   +
   +  /* If not null, format to use when reporting newly made
   directories.  */
   +  char const *created_directory_format;
   +};
   +
   +static void
   +announce_mkdir (char const *dir, void *options)
   +{
   +  struct mkdir_options const *o = options;
   +  if (o->created_directory_format)
   +    error (0, 0, o->created_directory_format, quote (dir));
   +}
   +
   +/* Make ancestor directory DIR, whose last component is COMPONENT,
   +   with options OPTIONS.  Assume the working directory is COMPONENT's
   +   parent.  Return 0 if successful and the resulting directory is
   +   readable, 1 if successful but the resulting directory is not
   +   readable, -1 (setting errno) otherwise.  */
   +static int
   +make_ancestor (char const *dir, char const *component, void *options)
   +{
   +  struct mkdir_options const *o = options;
   +  int r = mkdir (component, o->ancestor_mode);
   +  if (r == 0)
   +    {
   +      r = ! (o->ancestor_mode & S_IRUSR);
   +      announce_mkdir (dir, options);
   +    }
   +  return r;
   +}
   +
   +/* </hack> */
   +
    /* Update the time of file FILE according to the options given.
       Return true if successful.  */
    
   @@ -129,6 +185,19 @@
        fd = STDOUT_FILENO;
      else if (! no_create)
        {
   +      {
   +        char *dir = dir_name (file);
   +        struct savewd wd;
   +        savewd_init (&wd);
   +        void *make_ancestor_function = make_ancestor;
   +        struct mkdir_options options;
   +        mode_t mode = options.mode = options.ancestor_mode = S_IRWXUGO;
   +        mode_t mode_bits = options.mode_bits = 0;
   +        make_dir_parents (dir, &wd, make_ancestor_function, &options,
   +                          mode, announce_mkdir,
   +                          mode_bits, (uid_t) -1, (gid_t) -1, true);
   +      }
   +         
          /* Try to open FILE, creating it if necessary.  */
          fd = fd_reopen (STDIN_FILENO, file,
              O_WRONLY | O_CREAT | O_NONBLOCK | O_NOCTTY,


   This feels fairly hacky to me, as there's a fair amount of code
   duplication from mkdir.c - my hope is that the coreutils maintainers
   can take this and clean it up, perhaps by moving some of the common
   functionality into the lib directory.

   I hope this is useful. Happy holidays all.

   -Marc
    http://marc.abramowitz.info/



--
Marc Abramowitz
 
http://marc.abramowitz.info