Dear all:
We think there is a problem with eCos' chdir. When this fileio's function
is passed an empty
string as its argument, eCos' chdir does nothing and will not fail.
Calling chdir("") seems to
have the same effect as chdir(".").
However, as far as POSIX standard is concerned, calling chdir("") should
fail and return ENOENT,
just as described below(from POSIX document), please NOTE the contents in
the stars:
------------------------------------------------------------------------------------------------
The chdir() function shall fail if:
[EACCES]
Search permission is denied for any component of the pathname.
[ELOOP]
A loop exists in symbolic links encountered during resolution of the path
argument.
[ENAMETOOLONG]
The length of the path argument exceeds {PATH_MAX} or a pathname component
is longer than
{NAME_MAX}.
***********************************************************************************************
[ENOENT]
A component of path does not name an existing directory or path is an
empty string.
***********************************************************************************************
[ENOTDIR]
A component of the pathname is not a directory.
------------------------------------------------------------------------------------------------
We assume that eCos is in accord with POSIX as a matter of course, and we
think maybe this
problem can be resolved by adding a check condition to cyg_mtab_lookup
function, cause chdir
(open, mkdir, etc. are the same) will call cyg_mtab_lookup()
------------------------------------------------------------------------------------------------
1 __externC int cyg_mtab_lookup( cyg_dir *dir, const char **name,
cyg_mtab_entry **mte)
2 {
3 cyg_mtab_entry *m, *best = NULL;
4 int best_len = 0;
5
6 // Unrooted file names start from current dir
7 if( **name != '/' ) {
8 int cwd_len;
9 if (*mte == (cyg_mtab_entry *)NULL) {
10 // No known current directory
11 return -1;
12 }
13 ...
14 }
------------------------------------------------------------------------------------------------
we add to line 5
------------------------------------------------------------------------------------------------
3 cyg_mtab_entry *m, *best = NULL;
4 int best_len = 0;
5
if (**name == '\0') // if an empty string, then **name == '\0'
return -1;
6 // Unrooted file names start from current dir
7 if( **name != '/' ) {
8 int cwd_len;
9 if (*mte == (cyg_mtab_entry *)NULL) {
10 // No known current directory
11 return -1;
12 }
13 ...
14 }
------------------------------------------------------------------------------------------------
But we are not sure whether we are correct, or maybe eCos has some deep
consideration, so could
you please examine this, then tell us whether we are right or explain for
us, thank you so much.
Sincerely Yours
***********************************************
Beijing Sunnorth eCos Maintainer Group
Maintainers:
[EMAIL PROTECTED]
[EMAIL PROTECTED]
[EMAIL PROTECTED]
[EMAIL PROTECTED]
Bejing Sunnorth Electronic Technology Co.,LTD
***********************************************
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