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/* Written 2000 by Werner Almesberger */
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <unistd.h>
static int resolve_path(char *path, char *result, char *pos)
{
if (*path == '/') {
*result = '/';
pos = result+1;
++path;
}
*pos = 0;
if (!*path)
return 0;
while (1) {
struct stat st;
char *slash = *path ? strchr(path,'/') : NULL;
if (slash)
*slash = 0;
if (!path[0] || (path[0] == '.' && (!path[1] || (path[1] == '.' && !path[2])))) {
--pos;
if (pos != result && path[0] && path[1])
while (*--pos != '/');
}
else {
strcpy(pos,path);
if (lstat(result,&st) < 0)
return -1;
if (S_ISLNK(st.st_mode)) {
char buf[PATH_MAX_SIZE];
if (readlink(result,buf,sizeof(buf)) < 0)
return -1;
*pos = 0;
if (slash) {
*slash = '/';
strcat(buf, slash);
}
strcpy(path,buf);
if (*path == '/')
result[1] = 0;
pos = strchr(result,0);
continue;
}
pos = strchr(result,0);
}
if (slash) {
*pos++ = '/';
path = slash + 1;
}
*pos = 0;
if (!slash)
break;
}
return 0;
}
char *realpath(const char *path, char *resolved_path)
{
char cwd[PATH_MAX_SIZE];
char *path_copy;
int res;
if (!*path) {
errno = ENOENT;
return NULL;
}
if (!getcwd(cwd, sizeof(cwd)))
return NULL;
strcpy(resolved_path, "/");
if (resolve_path(cwd, resolved_path, resolved_path))
return NULL;
strcat(resolved_path, "/");
path_copy = strdup(path);
if (!path_copy)
return NULL;
res = resolve_path(path_copy, resolved_path, strchr(resolved_path, 0));
free(path_copy);
if (res)
return NULL;
return resolved_path;
}
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