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/* ISC license. */
/* MT-unsafe (because of chdir) */
#include <unistd.h>
#include <errno.h>
#include <skalibs/stralloc.h>
#include <skalibs/djbunix.h>
int sarealpath_tmp (stralloc *sa, char const *path, stralloc *tmp)
{
size_t tmpbase = tmp->len ;
size_t base = sa->len ;
unsigned int loop = 48 ;
int fdhere ;
int wasnull = !sa->s ;
if (!path) return (errno = EINVAL, -1) ;
if (!stralloc_cats(sa, path)) return -1 ;
fdhere = open_read(".") ;
if (fdhere == -1)
{
if (wasnull) stralloc_free(sa) ; else sa->len = base ;
return -1 ;
}
do
{
tmp->len = tmpbase ;
if (!loop--) { errno = ELOOP ; goto err ; }
if (!sadirname(tmp, sa->s + base, sa->len - base)
|| !stralloc_0(tmp)
|| (chdir(tmp->s + tmpbase) == -1))
goto err ;
tmp->len = tmpbase ;
if (!sabasename(tmp, sa->s + base, sa->len - base)
|| !stralloc_0(tmp)) goto err ;
sa->len = base ;
}
while (sareadlink(sa, tmp->s + tmpbase) >= 0) ;
if ((errno != EINVAL)
|| (sagetcwd(sa) == -1)
|| ((sa->len > base + 1) && !stralloc_catb(sa, "/", 1))
|| ((--tmp->len > tmpbase) && (tmp->s[tmpbase] != '/') && !stralloc_catb(sa, tmp->s + tmpbase, tmp->len - tmpbase)))
goto err ;
tmp->len = tmpbase ;
fd_chdir(fdhere) ;
fd_close(fdhere) ;
return 0 ;
err:
{
int e = errno ;
tmp->len = tmpbase ;
fd_chdir(fdhere) ;
fd_close(fdhere) ;
if (wasnull) stralloc_free(sa) ; else sa->len = base ;
errno = e ;
}
return -1 ;
}
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