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.
Then I thought that this might be a generally useful extension to touch, so I thought I’d take a stab at adding it directly to the touch source code in GNU coreutils. Here’s my patch, which I sent to the mailing list:
--- 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));
}
+/*
+ */
+
+/* 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;
+}
+
+/* */
+
/* 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;
and I also have this patch in Subversion here.
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.