Mail Archives: djgpp-workers/1996/04/30/06:56:13
Below is the latest version of `stat'. A problem related to Novell 3.x
was at last identified by a user who was persistent enough to debug it.
It turns out that `findfirst' succeeds when called with "dir/subdir/"
but fails for "dir/subdir/.", and gcc sometimes uses the last form. The
patch below makes this work. (I send the entire source because I
submitted a few previous changes, and I don't know what version do people
have.)
Everybody who works under Win95 or uses other unusual types of
filesystems, like network drives, Samba things, etc.--please try this
version and tell me if it fails. If not, this should be the version that
will go into the next DJGPP release. Thanks.
/* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
/* This is file STAT.C */
/*
* Almost a 100% U**X-compatible stat() substitute.
*
* Usage:
*
* That's easy: put this into libc.a, then just call stat() as usual.
*
* Rationale:
*
* Many Unix-born programs make heavy use of stat() library
* function to make decisions on files' equality, size, access
* attributes etc. In the MS-DOS environment, many implementations
* of stat() are crippled, because DOS makes it very hard to get to
* certain pieces of information about files and directories. Thus
* porting a program to DOS is usually an exercise in #ifdef'ing.
* This implementation facilitates porting Unix programs to MS-DOS
* by providing stat() which is much more Unix-compatible than those
* of most DOS-based C compilers (e.g., Borland's).
* Specifically, the following issues are taken care of:
*
* 1. This stat() doesn't fail for root directories, returning
* valid information.
* 2. Directory size is not reported zero; the number of used
* directory entries multiplied by entry size is returned instead.
* 3. Mode bits are set for all 3 groups (user, group, other).
* 4. Directories are NOT reported read-only, unless one of R, H or S
* attributes is set.
* 5. Directories have their execute bit set, as they do under Unix.
* 6. Device names (such as /dev/con, lpt1, aux etc.) are treated as
* if they were on a special drive called `@:' (st_dev = -1).
* The "character special" mode bit is set for these devices.
* 7. The inode number (st_ino) is taken from the starting cluster
* number of the file. If the cluster number is unavailable, it
* is invented using the file's name in a manner that minimizes
* the possibility of inventing an inode which already belongs
* to another file. See below for details.
* 8. Executable files are found based on files' extensions and
* magic numbers present at their beginning, and their execute
* bits are set.
*
* Lossage:
*
* Beautiful as the above sounds, this implementation does fail
* under certain circumstances. The following is a list of known
* problems:
*
* 1. The time fields for a root directory cannot be obtained, so
* they are set to the beginning of the Epoch.
* 2. For files which reside on networked drives, the inode number
* is invented, because network redirectors usually do not
* bring that info with them. This is not a total lossage, but
* it could get us a different inode for each program run.
* 3. Empty files do not have a starting cluster number, because
* DOS doesn't allocate one until you actually write something
* to a file. For these the inode is also invented.
* 4. If the st_ino field is a 16 bit number, the invented inode
* numbers are from 65535 and down, assuming that most disks have
* unused portions near their end. Valid cluster numbers are 16-bit
* unsigned integers, so a possibility of a clash exists, although
* the last 80 or more cluster numbers are unused on all drives
* I've seen. If the st_ino is 32 bit, then invented inodes are
* all greater than 64k, which totally eliminates a possibility
* of a clash with an actual cluster number.
* 5. The method of computing directory size is an approximation:
* a directory might consume much more space, if it has many
* deleted entries. Still, this is a close approximation, and
* it does follow the logic of reporting size for a regular file:
* only the actually used space is returned.
* 6. As this implementation relies heavily on undocumented DOS
* features, it will fail to get actual file info in environments
* other than native DOS, such as DR-DOS, OS/2 etc. For these,
* the function will return whatever info is available with
* conventional DOS calls, which is no less than any other
* implementation could do. This stat() might also fail for
* future DOS versions, if the layout of internal DOS data
* area is changed; however, this seems unlikely.
*
* Copyright (c) 1994-96 Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
*
* This software may be used freely so long as this copyright notice is
* left intact. There is no warranty on this software.
*
*/
/*
* Tested with DJGPP port of GNU C compiler, versions 1.11maint5 and 1.12,
* under MS-DOS 3.3, 4.01, 5.0, 6.20 (with and without DoubleSpace) and
* with networked drives under XFS 1.86, Novell Netware 3.22, and
* TSoft NFS 0.24Beta.
*
*/
#include <libc/stubs.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <time.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dos.h>
#include <dir.h>
#include <dpmi.h>
#include <go32.h>
#include <libc/farptrgs.h>
#include <libc/bss.h>
#include "xstat.h"
int __getdisk(void);
int __findfirst(const char *, struct ffblk *, int);
int __findnext(struct ffblk *);
#define ALL_FILES (FA_RDONLY|FA_HIDDEN|FA_SYSTEM|FA_DIREC|FA_ARCH)
#define _STAT_INODE 1 /* should we bother getting inode numbers? */
#define _STAT_EXEC_EXT 2 /* get execute bits from file extension? */
#define _STAT_EXEC_MAGIC 4 /* get execute bits from magic signature? */
#define _STAT_DIRSIZE 8 /* compute directory size? */
#define _STAT_ROOT_TIME 0x10 /* try to get root dir time stamp? */
#define _STAT_WRITEBIT 0x20 /* fstat() needs write bit? */
/* Should we bother about executables at all? */
#define _STAT_EXECBIT (_STAT_EXEC_EXT | _STAT_EXEC_MAGIC)
/* The structure of the full directory entry. This is the 32-byte
record present for each file/subdirectory in a DOS directory.
Although the ``packed'' attribute seems to be unnecessary, I use
it to be sure it will still work for future versions of GCC. */
struct full_dirent {
char fname[8] __attribute__ ((packed));
char fext[3] __attribute__ ((packed));
unsigned char fattr __attribute__ ((packed));
unsigned char freserved[10] __attribute__ ((packed));
unsigned short ftime __attribute__ ((packed));
unsigned short fdate __attribute__ ((packed));
unsigned short fcluster __attribute__ ((packed));
unsigned int fsize __attribute__ ((packed));
};
/* Static variables to speed up SDA DOS Swappable Data Area access on
subsequent calls. */
/* The count of number of SDA's we have. It is more than 1 for DOS
4.x only. If it has a value of 0, the function init_dirent_table()
will be called to compute the addresses where we are to look for
directory entry of our file. A value of -1 means this method is
unsupported for this version of DOS. */
static int dirent_count;
/* The table of places to look for our directory entry.
Each entry in the table is a linear offset from the beginning of
conventional memory which points to a particular location within
one of the SDA's, where the entry of a file being stat()'ed could
appear. The offsets are computed once (when the routine is first
called) and then reused for other calls. The actual storage for
the table is malloc()'ed when this function is first called. */
static unsigned int * dirent_table;
/* When we have only one SDA, this is where its only place to look for
directory entry is stored. */
static unsigned int dirent_place;
/* This holds the fail bits from the last call to init_dirent_table(),
so we can return them every time get_inode_from_sda() is called. */
static unsigned short init_dirent_table_bits;
/* Holds the last seen value of __bss_count, to be safe for
restarted programs (emacs). */
static int stat_count = -1;
/*
* Parts of the following code is derived from file DOSSWAP.C,
* which came with ``Undocumented DOS'', 1st edition.
*/
/* Compute table of pointers to look for directory entry of a file. */
static int
init_dirent_table (void)
{
short get_sda_func;
unsigned short dirent_offset;
unsigned short true_dos_version;
unsigned short dos_major, dos_minor;
__dpmi_regs regs;
if (dirent_count == -1) /* we already tried and found we can't */
return 0;
/* Compute INT 21h function number and offset of directory entry
from start of SDA. These depend on the DOS version.
We need exact knowledge about DOS internals, so we need the
TRUE DOS version (not the simulated one by SETVER), if that's
available. */
true_dos_version = _get_dos_version(1);
dos_major = true_dos_version >> 8;
dos_minor = true_dos_version & 0xff;
if ((dos_major == 3) && (dos_minor >= 10))
{
get_sda_func = 0x5d06;
dirent_offset = 0x1a7;
}
else if (dos_major == 4)
{
/* According to ``Undocumented DOS, 2nd edition'', I could have
used 5d06 here, as for DOS 5 and above, but I like to be
defensive. In fact, the above book itself uses 5d0b, contrary
to its own recommendation. */
get_sda_func = 0x5d0b;
dirent_offset = 0x1b3;
}
else if (dos_major >= 5)
{
get_sda_func = 0x5d06;
dirent_offset = 0x1b3;
}
else
{
_djstat_fail_bits |= _STFAIL_OSVER;
dirent_count = -1;
return 0;
}
_djstat_fail_bits &= ~_STFAIL_OSVER; /* version is OK */
/* Get the pointer to SDA by calling undocumented function 5dh of INT 21. */
regs.x.ax = get_sda_func;
__dpmi_int(0x21, ®s);
if (regs.x.flags & 1)
{
_djstat_fail_bits |= _STFAIL_SDA;
dirent_count = -1; /* if the call failed, never try this later */
return 0;
}
_djstat_fail_bits &= ~_STFAIL_SDA; /* Get SDA succeeded */
/* DOS 4.x might have several SDA's, which means we might have more
than one place to look into. (It is typical of DOS 4 to complicate
things.)
Compute all the possible addresses where we will have to look. */
if (dos_major == 4)
{
/* The pointer returned by INT 21h, AX=5D0b points to a header
which holds a number of SDA's and then an array of that number
of records each one of which includes address of an SDA (DWORD)
and its length and type (encoded in a WORD).
While walking this list of SDA's, we add to each pointer the
offset of directory entry and stash the resulting address in
our table for later use. */
int sda_list_walker = MK_FOFF(regs.x.ds, regs.x.si);
int i;
int *tbl;
dirent_count = _farpeekw(_dos_ds, sda_list_walker); /* number of SDA's */
/* Allocate storage for table. */
tbl = dirent_table = (int *)malloc(dirent_count*sizeof(int));
if (!dirent_table)
{
/* If malloc() failed, maybe later it will succeed, so don't
store -1 in dirent_count. */
dirent_count = 0;
_djstat_fail_bits |= _STFAIL_DCOUNT;
return 0;
}
memset(dirent_table, 0, dirent_count*sizeof(int));
_djstat_fail_bits &= ~_STFAIL_DCOUNT; /* dirent_count seems OK */
/* Walk the array of pointers, computing addresses of directory
entries and stashing them in our table. */
_farsetsel(_dos_ds);
for (i = dirent_count, sda_list_walker += 2; i--; sda_list_walker += 6)
{
int sda_start = _farnspeekl(sda_list_walker);
unsigned short sda_len = _farnspeekw(sda_list_walker + 4) & 0x7fff;
/* Let's be defensive here: if this SDA is too short to have
place for directory entry, we won't use it. */
if (sda_len > dirent_offset)
*tbl++ = sda_start + dirent_offset;
else
dirent_count--;
}
}
/* DOS 3.1 and 5.0 or later. We have only one SDA pointed to by
whatever INT 21h, AH=5d returns. */
else
{
dirent_count = 1;
dirent_place = MK_FOFF(regs.x.ds, regs.x.si) + dirent_offset;
dirent_table = &dirent_place;
}
return 1;
}
/* Get inode number by searching DOS Swappable Data Area.
The entire directory entry for a file found by FindFirst/FindNext
appears at a certain (version-dependent) offset in the SDA after
one of those function is called.
Should be called immediately after calling DOS FindFirst function,
before the info is overwritten by somebody who calls it again. */
static unsigned int
get_inode_from_sda(const char *basename)
{
int count = dirent_count;
unsigned int * dirent_p = dirent_table;
unsigned short dos_mem_base = _dos_ds;
unsigned short our_mem_base = _my_ds();
char * dot = strchr(basename, '.');
size_t total_len = strlen(basename);
int name_len = dot ? dot - basename : total_len;
int ext_len = dot ? total_len - name_len - 1 : 0;
int cluster_offset = offsetof(struct full_dirent, fcluster);
/* Restore failure bits set by last call to init_dirent_table(), so
they will be reported as if it were called now. */
_djstat_fail_bits = init_dirent_table_bits;
/* Force reinitialization in restarted programs (emacs). */
if (stat_count != __bss_count)
{
stat_count = __bss_count;
dirent_count = 0;
}
/* Initialize the table of SDA entries where we are to look for
our file. */
if (!dirent_count && !init_dirent_table())
{
init_dirent_table_bits = _djstat_fail_bits;
return 0;
}
init_dirent_table_bits = _djstat_fail_bits;
if (dirent_count == -1)
return 0;
count = dirent_count;
dirent_p = dirent_table;
_farsetsel(dos_mem_base);
/* This is DOS 4.x lossage: this loop might execute many times.
For other DOS versions it is executed exactly once. */
while (count--)
{
unsigned int src_address = *dirent_p & 0x000fffff;
char cmp_buf[sizeof(struct full_dirent)];
/* Copy the directory entry from the SDA to local storage.
The filename is stored there in infamous DOS format: name and
extension blank-padded to 8/3 characters, no dot between them. */
movedata(dos_mem_base, src_address, our_mem_base, (unsigned int)cmp_buf,
sizeof(struct full_dirent));
/* If this is the filename we are looking for, return
its starting cluster. */
if (!strncmp(cmp_buf, basename, name_len) &&
(ext_len == 0 || !strncmp(cmp_buf + 8, dot + 1, ext_len)))
return (unsigned int)_farnspeekw(*dirent_p + cluster_offset);
/* This is not our file. Search more, if more addresses left. */
dirent_p++;
}
/* If not found, give up. */
_djstat_fail_bits |= _STFAIL_BADSDA;
return 0;
}
static char blanks_8[] = " ";
static int
stat_assist(const char *path, struct stat *statbuf)
{
struct ffblk ff_blk;
char canon_path[MAX_TRUE_NAME];
char dos_path[MAX_TRUE_NAME];
int path_offset;
short drv_no;
unsigned dos_ftime;
_djstat_fail_bits = 0;
memset(statbuf, 0, sizeof(struct stat));
memset(&dos_ftime, 0, sizeof(dos_ftime));
/* Fields which are constant under DOS. */
statbuf->st_uid = getuid();
statbuf->st_gid = getgid();
statbuf->st_nlink = 1;
#ifndef NO_ST_BLKSIZE
statbuf->st_blksize = _go32_info_block.size_of_transfer_buffer;
#endif
/* Get the drive number.
If no explicit drive, assume current drive.
This might fail, if the name is of the form \\machine\path
(which means, it's on a networked drive), but we don't
consider such names legal here. In other words, DON'T call
stat() with a UNC name! */
if (path[1] == ':') /* explicit drive letter */
drv_no = toupper(*path) - 'A';
else
drv_no = __getdisk();
/* The drive part of the pathname that will be used
to call FindFirst. */
dos_path[0] = drv_no + 'A';
dos_path[1] = ':';
dos_path[2] = '\\';
dos_path[3] = '\0';
path_offset = 3;
/* Produce canonical pathname, with all the defaults resolved and
all redundant parts removed. This calls undocumented DOS
function 60h. */
if (_truename(path, canon_path))
{
/* Detect character device names which must be treated specially.
We could simply call FindFirst and test the 6th bit, but some
versions of DOS have trouble with this (see Ralph Brown's
Interrupt List, ``214E'', under `Bugs'). Instead we use
truename() which calls INT 21/AX=6000H. For character devices
it returns X:/DEVNAME, where ``X'' is the current drive letter
(note the FORWARD slash!). E.g., for CON or \dev\con it will
return C:/CON.
We will pretend that devices all reside on a special drive
called `@', which corresponds to st_dev = -1. This is because
these devices have no files, and we must invent inode numbers
for them; this scheme allows to lower a risk of clash between
invented inode and one which belongs to a real file. This is
also compatible with what our fstat() does.
*/
if (canon_path[2] == '/')
{
char dev_name[9]; /* devices are at most 8 characters long */
strncpy(dev_name, canon_path + 3, 8); /* the name without `X:/' */
dev_name[8] = '\0';
strcpy(canon_path, "@:\\dev\\");
strcat(canon_path, dev_name);
strncat(canon_path, blanks_8, 8 - strlen(dev_name)); /* blank-pad */
canon_path[15] = '\0'; /* ensure zero-termination */
/* Invent inode */
statbuf->st_ino = _invent_inode(canon_path, 0, 0);
/* Device code. */
statbuf->st_dev = -1;
#ifdef HAVE_ST_RDEV
statbuf->st_rdev = -1;
#endif
/* Set mode bits, including character special bit.
Should we treat printer devices as write-only? */
statbuf->st_mode |= (S_IFCHR | READ_ACCESS | WRITE_ACCESS);
/* We will arrange things so that devices have current time in
the access-time and modified-time fields of struct stat, and
zero (the beginning of times) in creation-time field. This
is consistent with what DOS FindFirst function returns for
character device names (if it succeeds--see above). */
statbuf->st_atime = statbuf->st_mtime = time(0);
statbuf->st_ctime = _file_time_stamp(dos_ftime);
return 0;
}
else if (canon_path[0] >= 'A' && canon_path[0] <= 'z' &&
canon_path[1] == ':' && canon_path[2] == '\\')
{
/* _truename() returned a name with a drive letter. (This is
always so for local drives, but some network redirectors
also do this.) We will take this to be the TRUE drive
letter, because _truename() knows about SUBST and JOIN.
If the canonicalized path returns in the UNC form (which
means the drive is remote), it cannot be SUBSTed or JOINed,
because SUBST.EXE and JOIN.EXE won't let you do it; so, for
these cases, there is no problem in believing the drive
number we've got from the original path or from __getdisk().
Or is there?... */
drv_no = toupper(canon_path[0]) - 'A';
}
else if (canon_path[0] == '\\' && canon_path[1] == '\\')
{
/* We get a UNC. We need to know what is the prefix of
the UNC that corresponds to the DOS drive letter. In
other words, if we get "\\SERV\VOL\DIR\SUBDIR\FILE", we
want to know the offset into `canon_path' that will get
us past the "\\SERV\VOL\" part to "DIR\SUBDIR\FILE".
We need this to call FindFirst with a pathname it can
grok, and it doesn't know about UNCs. */
char test_dir[MAX_TRUE_NAME];
if (_truename (dos_path, test_dir))
path_offset = strlen (test_dir);
else
path_offset = 0; /* what else can we do if `_truename' fails? */
/* DOS_PATH already includes a slash after the colon. We
need to get to the first character after the slash. */
while (canon_path[path_offset] == '\\')
path_offset++;
}
}
else
{
/* _truename() failed. (This really shouldn't happen, but who knows?)
At least uppercase all letters, convert forward slashes to backward
ones, and pray... */
register const char *src = path;
register char *dst = canon_path;
while ( (*dst = (*src > 'a' && *src < 'z'
? *src++ - ('a' - 'A')
: *src++)) != '\0')
{
if (*dst == '/')
*dst = '\\';
dst++;
}
path_offset = -1;
strcpy (dos_path, canon_path);
_djstat_fail_bits |= _STFAIL_TRUENAME;
}
/* Call DOS FindFirst function, which will bring us most of the info.
Note the use of DOS_PATH instead of CANON_PATH. This is because
for networked drives _truename() changes the drive letter to a
redirector-specific string (called the UNC notation), which might
include the machine name, and several parent directories above the
root of our mounted filesystem. E.g., under Novell we might have
\\MACHINE\ROOTDIR\OURDIR, where our tree on that drive starts with
OURDIR; Tsoft NFS (0.24Beta) gets us NFS.X:\OURDIR, where X is the
original drive letter; other redirectors will probably do their
weird things. This could totally confuse FindFirst. DOS_PATH takes
the pathname from CANON_PATH, but replaces the UNC prefix with a
drive letter.
*/
if (path_offset >= 0)
strcpy (dos_path + 3, canon_path + path_offset);
if (!__findfirst(dos_path, &ff_blk, ALL_FILES))
{
/* Time fields. */
dos_ftime =
( (unsigned short)ff_blk.ff_fdate << 16 ) +
(unsigned short)ff_blk.ff_ftime;
if ( (_djstat_flags & _STAT_INODE) == 0 )
{
/* For networked drives, don't believe the starting cluster
that the network redirector feeds us; always invent inode.
This is because network redirectors leave bogus values there,
and we don't have enough info to decide if the starting
cluster value is real or just a left-over from previous call.
For local files, try first using DOS SDA to get the inode from
the file's starting cluster number; if that fails, invent inode.
Note that the if clause below tests for non-zero value returned
by is_remote_drive(), which includes possible failure (-1).
This is because findfirst() already succeeded for our pathname,
and therefore the drive is a legal one; the only possibility that
is_remote_drive() fails is that some network redirector takes
over IOCTL functions in an incompatible way, which means the
drive is remote. QED. */
if (_is_remote_drive(drv_no) ||
(statbuf->st_ino = get_inode_from_sda(ff_blk.ff_name)) == 0)
{
_djstat_fail_bits |= _STFAIL_HASH;
statbuf->st_ino =
_invent_inode(canon_path, dos_ftime, ff_blk.ff_fsize);
}
}
/* File size. */
statbuf->st_size = ff_blk.ff_fsize;
/* Mode bits. */
statbuf->st_mode |= READ_ACCESS;
if ( !(ff_blk.ff_attrib & 0x07) ) /* no R, H or S bits set */
statbuf->st_mode |= WRITE_ACCESS;
/* Directories should have Execute bits set. */
if (ff_blk.ff_attrib & 0x10)
statbuf->st_mode |= (S_IFDIR | EXEC_ACCESS);
else
{
/* This is a regular file. */
char *extension = strrchr(ff_blk.ff_name, '.');
/* Set regular file bit. */
statbuf->st_mode |= S_IFREG;
if ((_djstat_flags & _STAT_EXECBIT) != _STAT_EXECBIT)
{
/* Set execute bits based on file's extension and
first 2 bytes. */
if (extension)
extension++; /* get past the dot */
if (_is_executable(dos_path, -1, extension))
statbuf->st_mode |= EXEC_ACCESS;
}
}
}
/* Detect root directories. These are special because, unlike
subdirectories, FindFirst fails for them. If you think the
simple test of the string returned by _truename() to have
":\\" at its end will suffice, think again. A network
redirector could tweak what _truename() returns to be
utterly unrecognizable as root directory. */
else
{
static char root_dir_pat[] = " :\\";
char root_dir[sizeof(root_dir_pat)];
/* Construct "X:\", where X is the drive letter. */
strcpy(root_dir, root_dir_pat);
root_dir[0] = drv_no + 'A';
if (strcmp(canon_path + 1, ":\\"))
{
/* The simple test of having "X:\" in canonical pathname
failed. Feed _truename() with root directory on that
drive and see if it returns identical to our CANON_PATH. */
char root_path[MAX_TRUE_NAME];
char *p;
if (!(p = _truename(root_dir, root_path)) || strcmp(p, canon_path))
{
/* The root is different, or the drive is inaccessible.
This might be a non-existing file/directory or a volume
label. */
#ifdef S_IFLABEL
/* Check for volume labels. We did not mix FA_LABEL with
other attributes in the call to `__findfirst' above,
because some environments will return bogus info in
that case. For instance, Win95 and WinNT seem to
ignore `path' and return the volume label even if it
doesn't fit the name in `path'. This fools us to
think that a non-existent file exists and is a volume
label. Hence the test for the returned name. */
if (!__findfirst(dos_path, &ff_blk, FA_LABEL))
{
int i = strlen (ff_blk.ff_name) - 1;
int j = strlen (dos_path) - 1;
if (j > i)
{
for ( ; i >= 0 && j >= 0; i--, j--)
if (toupper(ff_blk.ff_name[i]) != toupper(path[j]))
break;
}
if (i < 0
&& (dos_path[j] == '/'
|| dos_path[j] == '\\' || dos_path[j] == ':'))
{
/* Indeed a label. */
statbuf->st_mode = READ_ACCESS | S_IFLABEL;
statbuf->st_ino = 1;
statbuf->st_size = 0;
dos_ftime =
( (unsigned)ff_blk.ff_fdate << 16 ) + ff_blk.ff_ftime;
goto almost_done;
}
}
#endif
errno = ENOENT; /* FindFirst sets it to ENMFILE */
return -1;
}
}
/* Still here, so this is root directory. Assemble the information
for stat_buf. */
/* Mode bits. */
statbuf->st_mode |= (S_IFDIR | READ_ACCESS | WRITE_ACCESS | EXEC_ACCESS);
/* Root directory will have an inode = 1. Valid cluster numbers
for real files under DOS start with 2. */
statbuf->st_ino = 1;
/* Simulate zero size. This is what FindFirst returns for every
sub-directory. Later we might compute a better approximation
(see below). */
ff_blk.ff_fsize = 0L;
/* The time fields are left to be zero, unless the user wants us
to try harder. In the latter case, we check if the root has
a volume label entry, and use its time if it has. */
if ( (_djstat_flags & _STAT_ROOT_TIME) == 0 )
{
char buf[7];
strcpy(buf, root_dir);
strcat(buf, "*.*");
if (!__findfirst(buf, &ff_blk, FA_LABEL))
dos_ftime = ( (unsigned)ff_blk.ff_fdate << 16 ) + ff_blk.ff_ftime;
else
_djstat_fail_bits |= _STFAIL_LABEL;
}
}
almost_done:
/* Device code. */
statbuf->st_dev = drv_no;
#ifdef HAVE_ST_RDEV
statbuf->st_rdev = drv_no;
#endif
/* Time fields. */
statbuf->st_atime = statbuf->st_mtime = statbuf->st_ctime =
_file_time_stamp(dos_ftime);
if ( ! strcmp(ff_blk.lfn_magic,"LFN32") )
{
unsigned xtime;
xtime = *(unsigned *)&ff_blk.lfn_ctime;
if(xtime) /* May be zero if file written w/o lfn active */
statbuf->st_ctime = _file_time_stamp(xtime);
xtime = *(unsigned *)&ff_blk.lfn_atime;
if(xtime > dos_ftime) /* Accessed time is date only, no time */
statbuf->st_atime = _file_time_stamp(xtime);
}
if ( (statbuf->st_mode & S_IFMT) == S_IFDIR
&& (_djstat_flags & _STAT_DIRSIZE) == 0 )
{
/* Under DOS, directory entries for subdirectories have
zero size. Therefore, FindFirst brings us zero size
when called on a directory. (Some network redirectors
might do a better job, thus below we also test for zero size
actually being returned.) If we have zero-size directory,
we compute here the actual directory size by reading its
entries, then multiply their number by 32 (the size of a
directory entry under DOS). This might lose in the case
that many files were deleted from a once huge directory,
because AFAIK, directories don't return unused clusters to
the disk pool. Still, it is a good approximation of the
actual directory size.
We also take this opportunity to return the number of links
for directories as Unix programs expect it to be: the number
of subdirectories, plus 2 (the directory itself and the ``.''
entry).
The (max) size of the root directory could also be taken from
the disk BIOS Parameter Block (BPB) which can be obtained
by calling IOCTL (INT 21/AH=44H), subfunction 0DH, minor
function 60H. But we will treat all directories the same,
even at performance cost, because it's more robust for
networked drives. */
size_t pathlen = strlen(dos_path);
char lastc = dos_path[pathlen - 1];
char *search_spec = (char *)alloca(pathlen + 10); /* need only +5 */
int nfiles = 0, nsubdirs = 0, done;
strcpy(search_spec, dos_path);
if (lastc == '/' || lastc == '\\' || lastc == ':')
strcat(search_spec, "*.*");
else
strcat(search_spec, "\\*.*");
/* Count files and subdirectories. */
for (done = __findfirst(search_spec, &ff_blk, ALL_FILES);
!done;
done = __findnext(&ff_blk))
{
/* Don't count "." and ".." entries. This will show empty
directories as size 0. */
if (! (ff_blk.ff_name[0] == '.'
&& (ff_blk.ff_name[1] == '\0'
|| (ff_blk.ff_name[1] == '.'
&& ff_blk.ff_name[2] == '\0'))))
{
nfiles++;
if (ff_blk.ff_attrib & 0x10)
nsubdirs++;
}
}
statbuf->st_nlink = nsubdirs + 2;
if (statbuf->st_size == 0)
statbuf->st_size = nfiles * sizeof(struct full_dirent);
}
return 0;
}
/* Main entry point. This is library stat() function.
*/
int
stat(const char *path, struct stat *statbuf)
{
int e = errno;
char pathname[MAX_TRUE_NAME], *p;
if (!path || !statbuf)
{
errno = EFAULT;
return -1;
}
strcpy(pathname, path);
p = pathname + strlen(pathname) - 1;
/* Get rid of trailing slash. It confuses FindFirst and also causes
the inode-inventing mechanism think d:/path/ and d:/path are
different, because _truename() retains one trailing slash. But
leave alone a trailing slash if it's a root directory, like in
"/" or "d:/" */
while (p > pathname && p[-1] != ':' && (*p == '/' || *p == '\\'))
*p-- = '\0';
/* Under DOS it is customary to use "X:" for the CURRENT directory
of drive X. But FindFirst doesn't like this, so we convert it
to "X:." which works. This eliminates multiple #ifdef's in
many Unix-born programs. */
if (*p++ == ':')
{
*p++ = '.';
*p = '\0';
}
if (stat_assist(pathname, statbuf) == -1)
{
return -1; /* errno set by stat_assist() */
}
else
{
errno = e;
return 0;
}
}
#ifdef TEST
unsigned short _djstat_flags = 0;
void
main(int argc, char *argv[])
{
struct stat stat_buf;
char *endp;
if (argc < 2)
{
fprintf (stderr, "Usage: %s <_djstat_flags> <file...>\n", argv[0]);
exit(0);
}
stat(*argv, &stat_buf);
fprintf(stderr, "DOS %d.%d (%s)\n", _osmajor, _osminor, _os_flavor);
argc--; argv++;
_djstat_flags = (unsigned short)strtoul(*argv, &endp, 0);
argc--; argv++;
while (argc--)
{
if (!stat(*argv, &stat_buf))
{
fprintf(stderr, "%s: %d %6u %o %d %d %ld %lu %s", *argv,
stat_buf.st_dev,
(unsigned)stat_buf.st_ino,
stat_buf.st_mode,
stat_buf.st_nlink,
stat_buf.st_uid,
(long)stat_buf.st_size,
(unsigned long)stat_buf.st_mtime,
ctime(&stat_buf.st_mtime));
_djstat_describe_lossage(stderr);
}
else
{
fprintf(stderr, "%s: lossage", *argv);
perror(" ");
_djstat_describe_lossage(stderr);
}
++argv;
}
exit (0);
}
#endif
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