123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990 |
- /* Concatenate two arbitrary file names.
- Copyright (C) 1996-2007, 2009-2021 Free Software Foundation, Inc.
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <https://www.gnu.org/licenses/>. */
- /* Written by Jim Meyering. */
- #include <config.h>
- /* Specification. */
- #include "filenamecat.h"
- #include <stdlib.h>
- #include <string.h>
- #include "basename-lgpl.h"
- #include "filename.h"
- #if ! HAVE_MEMPCPY && ! defined mempcpy
- # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
- #endif
- /* Concatenate two file name components, DIR and BASE, in
- newly-allocated storage and return the result.
- The resulting file name F is such that the commands "ls F" and "(cd
- DIR; ls ./BASE)" refer to the same file. If necessary, put
- a separator between DIR and BASE in the result. Typically this
- separator is "/", but in rare cases it might be ".".
- In any case, if BASE_IN_RESULT is non-NULL, set
- *BASE_IN_RESULT to point to the copy of BASE at the end of the
- returned concatenation.
- If malloc fails, return NULL with errno set. */
- char *
- mfile_name_concat (char const *dir, char const *base, char **base_in_result)
- {
- char const *dirbase = last_component (dir);
- size_t dirbaselen = base_len (dirbase);
- size_t dirlen = dirbase - dir + dirbaselen;
- size_t baselen = strlen (base);
- char sep = '\0';
- if (dirbaselen)
- {
- /* DIR is not a file system root, so separate with / if needed. */
- if (! ISSLASH (dir[dirlen - 1]) && ! ISSLASH (*base))
- sep = '/';
- }
- else if (ISSLASH (*base))
- {
- /* DIR is a file system root and BASE begins with a slash, so
- separate with ".". For example, if DIR is "/" and BASE is
- "/foo" then return "/./foo", as "//foo" would be wrong on
- some POSIX systems. A fancier algorithm could omit "." in
- some cases but is not worth the trouble. */
- sep = '.';
- }
- char *p_concat = malloc (dirlen + (sep != '\0') + baselen + 1);
- if (p_concat == NULL)
- return NULL;
- {
- char *p;
- p = mempcpy (p_concat, dir, dirlen);
- *p = sep;
- p += sep != '\0';
- if (base_in_result)
- *base_in_result = p;
- p = mempcpy (p, base, baselen);
- *p = '\0';
- }
- return p_concat;
- }
|