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/*
* Crossfire -- cooperative multi-player graphical RPG and adventure game
*
* Copyright (c) 1999-2014 Mark Wedel and the Crossfire Development Team
* Copyright (c) 1992 Frank Tore Johansen
*
* Crossfire is free software and comes with ABSOLUTELY NO WARRANTY. You are
* welcome to redistribute it under certain conditions. For details, please
* see COPYING and LICENSE.
*
* The authors can be reached via e-mail at <crossfire@metalforge.org>.
*/
/**
* @file path.c
* Contains file path manipulation functions.
*/
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <global.h>
#include "define.h"
#include "path.h"
#if 0
/**
* Define DEBUG_PATH to enable debug output.
*/
#define DEBUG_PATH
#endif
/**
* Combines 2 paths, which can be relative.
*
* @param src
* path we're starting from.
* @param dst
* path we're doing to.
* @param path
* buffer containing the combined path.
* @param size
* size of path.
* @return
* path.
*
* @note
* this doesn't handle the '..', check path_normalize().
*/
char *path_combine(const char *src, const char *dst, char *path, size_t size) {
char *p;
if (*dst == '/' || *dst == '~') {
/* absolute destination path => ignore source path */
strlcpy(path, dst, size);
} else {
/* relative destination path => add after last '/' of source */
strlcpy(path, src, size);
p = strrchr(path, '/');
if (p != NULL) {
p++;
} else {
p = path;
if (*src == '/')
*p++ = '/';
}
strlcpy(p, dst, size-(p-path));
}
#if defined(DEBUG_PATH)
LOG(llevDebug, "path_combine(%s, %s) = %s\n", src, dst, path);
#endif
return(path);
}
/**
* Cleans specified path. Removes .. and things like that.
*
* @param path
* path to clear. It will be modified in place.
* @note
* there shouldn't be any buffer overflow, as we just remove stuff.
*/
void path_normalize(char *path) {
char *p; /* points to the beginning of the path not yet processed; this is
either a path component or a path separator character */
char *q; /* points to the end of the path component p points to */
char *w; /* points to the end of the already normalized path; w <= p is
maintained */
size_t len; /* length of current component (which p points to) */
#if defined(DEBUG_PATH)
LOG(llevDebug, "path_normalize: input '%s'\n", path);
#endif
p = path;
w = p;
while (*p != '\0') {
if (*p == '/') {
if ((w == path && *path == '/') || (w > path && w[-1] != '/'))
*w++ = '/';
p++;
continue;
}
q = strchr(p, '/');
if (q == NULL)
q = p+strlen(p);
len = q-p;
assert(len > 0);
#if defined(DEBUG_PATH)
LOG(llevDebug, "path_normalize: checking '%.*s'\n", (int)len, p);
#endif
if (len == 1 && *p == '.') {
/* remove current component */
} else if (len == 2 && memcmp(p, "..", 2) == 0) {
if (w == path || (w == path+3 && memcmp(path, "../", 3) == 0)) {
/* keep ".." at beginning of relative path ("../x" => "../x") */
memmove(w, p, len);
w += len;
} else if (w == path+1 && *path == '/') {
/* remove ".." at beginning of absolute path ("/../x" => "/x") */
} else {
/* remove both current component ".." and preceding one */
if (w > path && w[-1] == '/')
w--;
while (w > path && w[-1] != '/')
w--;
}
} else {
/* normal component ==> add it */
memmove(w, p, len);
w += len;
}
p = q;
#if defined(DEBUG_PATH)
LOG(llevDebug, "path_normalize: so far '%.*s'\n", (int)(w-path), path);
#endif
}
/* remove trailing slashes, but keep the one at the start of the path */
while (w > path+1 && w[-1] == '/') {
w--;
}
*w = '\0';
#if defined(DEBUG_PATH)
LOG(llevDebug, "path_normalize: result '%s'\n", path);
#endif
}
/**
* Combines the 2 paths.
*
* @param src
* path we're starting from.
* @param dst
* path we're getting to.
* @param path
* buffer that will contain combined paths.
* @param size
* length of path.
* @return
* path
*/
char *path_combine_and_normalize(const char *src, const char *dst, char *path, size_t size) {
path_combine(src, dst, path, size);
path_normalize(path);
return(path);
}
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