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/* ISC license. */
#include <errno.h>
#include <sys/stat.h>
#include <skalibs/djbunix.h>
static unsigned char cclass (char c)
{
switch (c)
{
case 0 : return 0 ;
case '/' : return 1 ;
case '.' : return 2 ;
default : return 3 ;
}
}
/* out must be at least strlen(in) + 2 bytes */
size_t path_canonicalize (char *out, char const *in, int check)
{
static unsigned char const table[4][4] =
{
{ 0x04, 0x00, 0x12, 0x11 },
{ 0x04, 0x50, 0x11, 0x11 },
{ 0x24, 0x20, 0x13, 0x11 },
{ 0xa4, 0xa0, 0x11, 0x11 }
} ;
int isabsolute = in[0] == '/' ;
size_t j = 0 ;
unsigned int depth = 0 ;
unsigned char state = 0 ;
if (isabsolute) *out++ = *in++ ;
while (state < 4)
{
char c = *in++ ;
unsigned char what = table[state][cclass(c)] ;
state = what & 0x07 ;
if (what & 0x80)
{
if (depth)
{
depth-- ;
j -= 3 ;
if (check)
{
struct stat st ;
out[j] = 0 ;
if (stat(out - isabsolute, &st) < 0) return 0 ;
if (!S_ISDIR(st.st_mode)) return (errno = ENOTDIR, 0) ;
}
}
else if (!isabsolute)
{
out[j++] = '/' ;
out[j++] = '.' ;
}
}
if (what & 0x40) depth++ ;
if (what & 0x20) while (j && out[j-1] != '/') j-- ;
if (what & 0x10) out[j++] = c ;
}
if (j && out[j-1] == '/') j-- ;
if (!j && !isabsolute) out[j++] = '.' ;
out[j] = 0 ;
return j ;
}
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