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Better code for traversing symlinks so that relative symlinks are understood

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jjgarcia 2004-11-22 14:33:14 +00:00
parent 6c445495ae
commit 83e5db4c77
1 changed files with 50 additions and 50 deletions
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100
src/c/unixfsys.d
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@ -126,44 +126,28 @@ si_file_kind(cl_object filename, cl_object follow_links) {
@(return file_kind(filename->string.self, !Null(follow_links)))
}
#if defined(mingw32) || defined(_MSC_VER)
#define si_follow_symlink si_coerce_to_filename
#else
#if defined(HAVE_LSTAT) && !defined(mingw32) && !defined(_MSV_VER)
static cl_object
si_follow_symlink(cl_object filename) {
/* This routine outputs a namestring in which all the symbolic links
* have been resolved.
*/
cl_object output, kind;
si_readlink(cl_object filename) {
/* Given a filename which is a symlink, this routine returns
* the value of this link in the form of a pathname. */
cl_index size = 128, written;
output = si_coerce_to_filename(filename);
cl_object output, kind;
do {
output = cl_alloc_adjustable_string(size);
written = readlink(filename->string.self, output->string.self, size);
size += 256;
} while(written == size);
output->string.self[written] = '\0';
kind = file_kind(output->string.self, FALSE);
#ifdef HAVE_LSTAT
while (kind == @':link') {
cl_object aux;
do {
aux = cl_alloc_adjustable_string(size);
written = readlink(output->string.self, aux->string.self, size);
size += 256;
} while(written == size);
aux->string.self[written] = '\0';
output = aux;
kind = file_kind(output->string.self, FALSE);
if (kind == @':directory') {
output->string.self[written++] = '/';
output->string.self[written] = '\0';
}
output->string.fillp = written;
if (kind == @':directory') {
output->string.self[written++] = '/';
output->string.self[written] = '\0';
}
#endif
if (kind == @':directory' &&
output->string.self[output->string.fillp-1] != '/')
FEerror("Filename ~S actually points to a directory", 1, filename);
return ((kind == Cnil)? Cnil : output);
output->string.fillp = written;
return output;
}
#endif /* !mingw32 */
#endif /* HAVE_LSTAT */
/*
@ -174,7 +158,7 @@ si_follow_symlink(cl_object filename) {
cl_object
cl_truename(cl_object pathname)
{
cl_object dir, filename;
cl_object dir;
cl_object previous = current_dir();
pathname = coerce_to_file_pathname(pathname);
@ -182,19 +166,27 @@ cl_truename(cl_object pathname)
if (pathname->pathname.directory == Cnil)
pathname = merge_pathnames(previous, pathname, @':newest');
/* First we ensure that PATHNAME itself does not point to a symlink. */
filename = si_follow_symlink(pathname);
if (filename == Cnil) {
FEcannot_open(pathname);
} else {
filename = cl_parse_namestring(3, filename, Cnil, Cnil);
}
/* Next we process the directory part of the filename, removing all
* possible symlinks. To do so, we only have to change to the directory
* which contains our file, and come back.
/* We process the directory part of the filename, removing all
* possible symlinks. To do so, we only have to change to the
* directory which contains our file, and come back. We also have to
* ensure that the filename itself does not point to a symlink: if so,
* then we resolve the value of the symlink and continue traversing
* the filesystem.
*/
CL_UNWIND_PROTECT_BEGIN {
#ifdef HAVE_LSTAT
cl_object kind, filename;
BEGIN:
filename = si_coerce_to_filename(pathname);
kind = file_kind(filename->string.self, FALSE);
if (kind == Cnil) {
FEcannot_open(pathname);
} else if (kind == @':link') {
filename = si_readlink(filename);
} else {
filename = OBJNULL;
}
#endif
#ifdef _MSC_VER
if (filename->pathname.device != Cnil)
{
@ -204,7 +196,7 @@ cl_truename(cl_object pathname)
goto ERROR;
}
#endif
for (dir = filename->pathname.directory;
for (dir = pathname->pathname.directory;
!Null(dir);
dir = CDR(dir))
{
@ -212,7 +204,7 @@ cl_truename(cl_object pathname)
if (type_of(part) == t_string) {
if (chdir(part->string.self) < 0) {
ERROR: FElibc_error("Can't change the current directory to ~S",
1, filename);
1, pathname);
}
} else if (part == @':absolute') {
if (chdir("/") < 0)
@ -226,12 +218,20 @@ ERROR: FElibc_error("Can't change the current directory to ~S",
FEerror("~S is not allowed in TRUENAME", 1, part);
}
}
filename = merge_pathnames(si_getcwd(), filename, @':newest');
#ifdef HAVE_LSTAT
if (filename) {
/* It was a symlink. We take the content of this
* link and try to find its truename. */
pathname = cl_parse_namestring(3, filename, Cnil, Cnil);
goto BEGIN;
}
#endif
pathname = merge_pathnames(si_getcwd(), pathname, @':newest');
} CL_UNWIND_PROTECT_EXIT {
chdir(previous->string.self);
} CL_UNWIND_PROTECT_END;
@(return filename)
@(return pathname)
}
FILE *
@ -368,7 +368,7 @@ homedir_pathname(cl_object user)
{
cl_index i;
cl_object namestring;
if (Null(user)) {
char *h = getenv("HOME");
namestring = (h == NULL)? make_constant_string("/")