void
set_current_wd(const char *nwd)
{
char *allocd = NULL;
if (nwd == NULL) {
allocd = ksh_get_wd();
nwd = allocd ? allocd : null;
}
afree(current_wd, APERM);
strdupx(current_wd, nwd, APERM);
afree(allocd, ATEMP);
}
void
set_current_wd(char *path)
{
int len;
char *p = path;
if (!p && !(p = ksh_get_wd((char *) 0, 0)))
p = null;
len = strlen(p) + 1;
if (len > current_wd_size)
current_wd = aresize(current_wd, current_wd_size = len, APERM);
memcpy(current_wd, p, len);
if (p != path && p != null)
afree(p, ATEMP);
}
void
set_current_wd(char *pathl)
{
size_t len = 1;
char *p = pathl;
if (p == NULL) {
if ((p = ksh_get_wd(&len)) == NULL)
p = null;
} else
len = strlen(p) + 1;
if (len > current_wd_size) {
afree(current_wd, APERM);
current_wd = alloc(current_wd_size = len, APERM);
}
memcpy(current_wd, p, len);
if (p != pathl && p != null)
afree(p, ATEMP);
}
char *
do_realpath(const char *upath)
{
char *xp, *ip, *tp, *ipath, *ldest = NULL;
XString xs;
size_t pos, len;
int llen;
struct stat sb;
#ifdef MKSH__NO_PATH_MAX
size_t ldestlen = 0;
#define pathlen sb.st_size
#define pathcnd (ldestlen < (pathlen + 1))
#else
#define pathlen PATH_MAX
#define pathcnd (!ldest)
#endif
/* max. recursion depth */
int symlinks = 32;
if (mksh_abspath(upath)) {
/* upath is an absolute pathname */
strdupx(ipath, upath, ATEMP);
} else {
/* upath is a relative pathname, prepend cwd */
if ((tp = ksh_get_wd()) == NULL || !mksh_abspath(tp))
return (NULL);
ipath = shf_smprintf("%s%s%s", tp, "/", upath);
afree(tp, ATEMP);
}
/* ipath and upath are in memory at the same time -> unchecked */
Xinit(xs, xp, strlen(ip = ipath) + 1, ATEMP);
/* now jump into the deep of the loop */
goto beginning_of_a_pathname;
while (*ip) {
/* skip slashes in input */
while (*ip == '/')
++ip;
if (!*ip)
break;
/* get next pathname component from input */
tp = ip;
while (*ip && *ip != '/')
++ip;
len = ip - tp;
/* check input for "." and ".." */
if (tp[0] == '.') {
if (len == 1)
/* just continue with the next one */
continue;
else if (len == 2 && tp[1] == '.') {
/* strip off last pathname component */
while (xp > Xstring(xs, xp))
if (*--xp == '/')
break;
/* then continue with the next one */
continue;
}
}
/* store output position away, then append slash to output */
pos = Xsavepos(xs, xp);
/* 1 for the '/' and len + 1 for tp and the NUL from below */
XcheckN(xs, xp, 1 + len + 1);
Xput(xs, xp, '/');
/* append next pathname component to output */
memcpy(xp, tp, len);
xp += len;
*xp = '\0';
/* lstat the current output, see if it's a symlink */
if (mksh_lstat(Xstring(xs, xp), &sb)) {
/* lstat failed */
if (errno == ENOENT) {
/* because the pathname does not exist */
while (*ip == '/')
/* skip any trailing slashes */
++ip;
/* no more components left? */
if (!*ip)
/* we can still return successfully */
break;
/* more components left? fall through */
}
/* not ENOENT or not at the end of ipath */
goto notfound;
}
/* check if we encountered a symlink? */
if (S_ISLNK(sb.st_mode)) {
#ifndef MKSH__NO_SYMLINK
/* reached maximum recursion depth? */
if (!symlinks--) {
/* yep, prevent infinite loops */
errno = ELOOP;
goto notfound;
}
/* get symlink(7) target */
if (pathcnd) {
#ifdef MKSH__NO_PATH_MAX
if (notoktoadd(pathlen, 1)) {
errno = ENAMETOOLONG;
goto notfound;
}
#endif
ldest = aresize(ldest, pathlen + 1, ATEMP);
}
llen = readlink(Xstring(xs, xp), ldest, pathlen);
if (llen < 0)
/* oops... */
goto notfound;
ldest[llen] = '\0';
/*
* restart if symlink target is an absolute path,
* otherwise continue with currently resolved prefix
*/
/* append rest of current input path to link target */
tp = shf_smprintf("%s%s%s", ldest, *ip ? "/" : "", ip);
afree(ipath, ATEMP);
ip = ipath = tp;
if (!mksh_abspath(ldest)) {
/* symlink target is a relative path */
xp = Xrestpos(xs, xp, pos);
} else
#endif
{
/* symlink target is an absolute path */
xp = Xstring(xs, xp);
beginning_of_a_pathname:
/* assert: (ip == ipath)[0] == '/' */
/* assert: xp == xs.beg => start of path */
/* exactly two leading slashes? (SUSv4 3.266) */
if (ip[1] == '/' && ip[2] != '/') {
/* keep them, e.g. for UNC pathnames */
Xput(xs, xp, '/');
}
}
}
/* otherwise (no symlink) merely go on */
}
/*
* either found the target and successfully resolved it,
* or found its parent directory and may create it
*/
if (Xlength(xs, xp) == 0)
/*
* if the resolved pathname is "", make it "/",
* otherwise do not add a trailing slash
*/
Xput(xs, xp, '/');
Xput(xs, xp, '\0');
/*
* if source path had a trailing slash, check if target path
* is not a non-directory existing file
*/
if (ip > ipath && ip[-1] == '/') {
if (stat(Xstring(xs, xp), &sb)) {
if (errno != ENOENT)
goto notfound;
} else if (!S_ISDIR(sb.st_mode)) {
errno = ENOTDIR;
goto notfound;
}
/* target now either does not exist or is a directory */
}
/* return target path */
if (ldest != NULL)
afree(ldest, ATEMP);
afree(ipath, ATEMP);
return (Xclose(xs, xp));
notfound:
/* save; freeing memory might trash it */
llen = errno;
if (ldest != NULL)
afree(ldest, ATEMP);
afree(ipath, ATEMP);
Xfree(xs, xp);
errno = llen;
return (NULL);
#undef pathlen
#undef pathcnd
}
