在vxworks下，如何判断指定的路径有无写权限

在vxworks下，怎么判断指定的路径有无写权限？
在vxworks下，怎么判断指定的路径有无写权限？
类似于linux下的access 系统调用

------解决方案--------------------------------------------------------
可参考ll命令的源码，我们输入ll命令后，会显示类似下面的信息
drwxrwxrwx 1 0 0 3267 Dec 12 14:07 BC31/

drwxrwxrwx这个显示目录是否可读写。它的原理是：struct stat * fileStat, /* stat() structure */

可查看一下ll命令的源码：
C:\Tornado2.2\target\src\usr\usrFsLib.c

LOCAL STATUS dirListEnt
(
int fd, /* file descriptor for output */
char * fileName, /* file name */
struct stat * fileStat, /* stat() structure */
char * prefix, /* prefix for short output */
BOOL doLong /* do Long listing format */
)
{
time_t now; /* current clock */
struct tm nowDate; /* current date & time */
struct tm fileDate; /* file date/time (long listing) */
const char *monthNames[] = {"???", "Jan", "Feb", "Mar", "Apr",
"May", "Jun", "Jul", "Aug", "Sep",
"Oct", "Nov", "Dec"};
char fType, modbits[10] ;
char suffix = ' '; /* print '/' after directory name */

if(doLong)
{
/* Break down file modified time */
time( &now );
localtime_r (&now, &nowDate);
localtime_r (&fileStat->st_mtime, &fileDate);

if (fileStat->st_attrib & DOS_ATTR_RDONLY)
fileStat->st_mode &= ~(S_IWUSR|S_IWGRP|S_IWOTH);

if (S_ISDIR (fileStat->st_mode))
{
fType = 'd' ;
suffix = '/';
}
else if (S_ISREG (fileStat->st_mode))
fType = '-' ;
else
fType = '?' ;

strcpy( modbits, "---------" );

modbits[0] = (fileStat->st_mode & S_IRUSR)? 'r':'-';
modbits[1] = (fileStat->st_mode & S_IWUSR)? 'w':'-';
modbits[2] = (fileStat->st_mode & S_IXUSR)? 'x':'-';
modbits[3] = (fileStat->st_mode & S_IRGRP)? 'r':'-';
modbits[4] = (fileStat->st_mode & S_IWGRP)? 'w':'-';
modbits[5] = (fileStat->st_mode & S_IXGRP)? 'x':'-';
modbits[6] = (fileStat->st_mode & S_IROTH)? 'r':'-';
modbits[7] = (fileStat->st_mode & S_IWOTH)? 'w':'-';
modbits[8] = (fileStat->st_mode & S_IXOTH)? 'x':'-';

if (fileStat->st_attrib & DOS_ATTR_ARCHIVE)
modbits[6] = 'A';
if(fileStat->st_attrib & DOS_ATTR_SYSTEM)
modbits[7] = 'S';
if(fileStat->st_attrib & DOS_ATTR_HIDDEN)
modbits[8] = 'H';

modbits[9] = EOS ;

/* print file mode */
fdprintf(fd, "%c%9s", fType, modbits);

/* fake links, user and group fields */
fdprintf(fd, " %2d %-7d %-7d ", fileStat->st_nlink,
fileStat->st_uid, fileStat->st_gid );

/* print file size - XXX: add 64 bit file size support */
fdprintf(fd, " %9lu ", fileStat->st_size );

/* print date */
if (fileDate.tm_year == nowDate.tm_year)
{
fdprintf(fd, "%s %2d %02d:%02d ",
monthNames [fileDate.tm_mon + 1],/* month */
fileDate.tm_mday, /* day of month */
fileDate.tm_hour, /* hour */
fileDate.tm_min /* minute */
);
}
else
{
fdprintf(fd, "%s %2d %04d ",
monthNames [fileDate.tm_mon + 1],/* month */
fileDate.tm_mday, /* day of month */
fileDate.tm_year+1900 /* year */
);
}

} /* if doLong */
else
{ /* short listing */
if (strcmp(prefix , ".") == 0 || prefix[0] == EOS)
/* dint print "." prefix */ ;
else if (prefix != NULL && prefix [ strlen(prefix) -1 ] != '/')
fdprintf(fd, "%s/", prefix);