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/* This file contains routines for creating and manipulating path strings.
*
* The entry points into this file are:
* make_path construct a path string for an inode
* push_path add a path component to the end of a path string
* pop_path remove the last path component from a path string
*
* Created:
* April 2009 (D.C. van Moolenbroek)
*/
#include "inc.h"
/*===========================================================================*
* make_path *
*===========================================================================*/
int make_path(char path[PATH_MAX], struct inode *ino)
{
/* Given an inode, construct the path identifying that inode.
*/
char buf[PATH_MAX], *p, *prefix;
size_t len, plen, total;
p = &buf[sizeof(buf) - 1];
p[0] = 0;
dprintf(("%s: make_path: constructing path for inode %d\n",
sffs_name, ino->i_num));
/* Get the length of the prefix, skipping any leading slashes. */
for (prefix = sffs_params->p_prefix; prefix[0] == '/'; prefix++);
plen = strlen(prefix);
/* Construct the path right-to-left in a temporary buffer first. */
for (total = plen; ino != NULL && !IS_ROOT(ino); ino = ino->i_parent) {
len = strlen(ino->i_name);
total += len + 1;
p -= len + 1;
if (total >= sizeof(buf))
return ENAMETOOLONG;
p[0] = '/';
memcpy(p + 1, ino->i_name, len);
}
/* If any of the intermediate inodes has no parent, the final inode is no
* longer addressable by name.
*/
if (ino == NULL)
return ENOENT;
/* Put the result in the actual buffer. We need the leading slash in the
* temporary buffer only when the prefix is not empty.
*/
if (!prefix[0] && p[0] == '/') p++;
strlcpy(path, prefix, PATH_MAX);
strlcpy(&path[plen], p, PATH_MAX - plen);
dprintf(("%s: make_path: resulting path is '%s'\n", sffs_name, path));
return OK;
}
/*===========================================================================*
* push_path *
*===========================================================================*/
int push_path(char path[PATH_MAX], char *name)
{
/* Add a component to the end of a path.
*/
size_t len, add;
len = strlen(path);
add = strlen(name);
if (len > 0) add++;
if (len + add >= PATH_MAX)
return ENAMETOOLONG;
if (len > 0) path[len++] = '/';
strlcpy(&path[len], name, PATH_MAX - len);
return OK;
}
/*===========================================================================*
* pop_path *
*===========================================================================*/
void pop_path(char path[PATH_MAX])
{
/* Remove the last component from a path.
*/
char *p;
p = strrchr(path, '/');
if (p == NULL) {
p = path;
/* Can't pop the root component */
assert(p[0] != 0);
}
p[0] = 0;
}
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