ruby-core

Yukihiro Matsumoto wrote:
> Hi,
>
> In message "Re: [ruby-core:17954] Expand_path -- Proposal: An alternate method"
>     on Fri, 25 Jul 2008 12:26:16 +0900, "C.E. Thornton" <admin@hawthorne-press.com> writes:
>
> |Shouldn't a program be able to expand ANY legitimate relative path
> |without worrying that some directory in a given tree contains a
> |dir  '~name' where the name "just" happens to be a user on your system?
> |
> |I can see the point of  'expand_path'  following the current convention, but
> |shouldn't there be a way to scan a directory tree without incurring errors
> |for legal directory names?
> |
> | It would follow these rules:
> | 1)    ~current_user   = /home/current_user
> | 2)    Any other directory specification, whether prefixed with
> |        a tilde or not would be interpreted literally.
> |
> | Suggested Method Names:   expand_absolute()
> |                                               absolute_path()  
>
> If I were going to add a new method, that method should convert paths
> from relative to absolute, no user name expansion.
>
> 							matz.
>
>
>   
I have included a patch for your evaluation for "absolute_path()".

It is based on 1.8.7. I inspected 1.9.0 and a similar patch should
also work on that version, Then New Function Documentation
is:

/*
* call-seq:
* File.absolute_path(file_name [, dir_string] ) -> abs_file_name
*
* Converts a pathname to an absolute pathname. Relative paths are
* referenced from the current working directory of the process unless
* <i>dir_string</i> is given, in which case it will be used as the
* starting point. If the given pathname starts with a ``<code>~</code>''
* it is NOT expanded, it is treated as a normal directory name.
*
* File.absolute_path("~oracle/bin") #=> "<relative_path>/~oracle/bin"
*/

Chuck T.

-- 
Competency and chastity have much in common,
they both encompass their own punishment! 

-- C.E. Thornton -- Hawthorne Press --

Attachments (1)

patch (2.5 KB, text/plain)

--- file.c	2008-08-08 01:53:53.000000000 +0000
+++ file.c_new	2008-08-08 01:48:29.000000000 +0000
@@ -2481,8 +2481,9 @@
 static int is_absolute_path _((const char*));
 
 static VALUE
-file_expand_path(fname, dname, result)
+file_expand_path(fname, dname, abs_mode, result)
     VALUE fname, dname, result;
+    int abs_mode;
 {
     char *s, *buf, *b, *p, *pend, *root;
     long buflen, dirlen;
@@ -2492,7 +2493,7 @@
     BUFINIT();
     tainted = OBJ_TAINTED(fname);
 
-    if (s[0] == '~') {
+    if (s[0] == '~' && abs_mode == 0) {
 	if (isdirsep(s[1]) || s[1] == '\0') {
 	    char *dir = getenv("HOME");
 
@@ -2684,7 +2685,7 @@
 rb_file_expand_path(fname, dname)
     VALUE fname, dname;
 {
-    return file_expand_path(fname, dname, rb_str_new(0, MAXPATHLEN + 2));
+    return file_expand_path(fname, dname, 0, rb_str_new(0, MAXPATHLEN + 2));
 }
 
 /*
@@ -2719,6 +2720,41 @@
     return rb_file_expand_path(fname, dname);
 }
 
+VALUE
+rb_file_absolute_path(fname, dname)
+    VALUE fname, dname;
+{
+    return file_expand_path(fname, dname, 1, rb_str_new(0, MAXPATHLEN + 2));
+}
+
+/*
+ *  call-seq:
+ *     File.absolute_path(file_name [, dir_string] ) -> abs_file_name
+ *  
+ *  Converts a pathname to an absolute pathname. Relative paths are
+ *  referenced from the current working directory of the process unless
+ *  <i>dir_string</i> is given, in which case it will be used as the
+ *  starting point. If the given pathname starts with a ``<code>~</code>''
+ *  it is NOT expanded, it is treated as a normal directory name.
+ *     
+ *     File.absolute_path("~oracle/bin")       #=> "<relative_path>/~oracle/bin"
+ */
+
+VALUE
+rb_file_s_absolute_path(argc, argv)
+    int argc;
+    VALUE *argv;
+{
+    VALUE fname, dname;
+
+    if (argc == 1) {
+	return rb_file_absolute_path(argv[0], Qnil);
+    }
+    rb_scan_args(argc, argv, "11", &fname, &dname);
+
+    return rb_file_absolute_path(fname, dname);
+}
+
 static int
 rmext(p, e)
     const char *p, *e;
@@ -4463,6 +4499,7 @@
     rb_define_singleton_method(rb_cFile, "umask", rb_file_s_umask, -1);
     rb_define_singleton_method(rb_cFile, "truncate", rb_file_s_truncate, 2);
     rb_define_singleton_method(rb_cFile, "expand_path", rb_file_s_expand_path, -1);
+    rb_define_singleton_method(rb_cFile, "absolute_path", rb_file_s_absolute_path, -1);
     rb_define_singleton_method(rb_cFile, "basename", rb_file_s_basename, -1);
     rb_define_singleton_method(rb_cFile, "dirname", rb_file_s_dirname, 1);
     rb_define_singleton_method(rb_cFile, "extname", rb_file_s_extname, 1);

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