diff options
Diffstat (limited to 'gnulib/import/filenamecat-lgpl.c')
-rw-r--r-- | gnulib/import/filenamecat-lgpl.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/gnulib/import/filenamecat-lgpl.c b/gnulib/import/filenamecat-lgpl.c new file mode 100644 index 0000000..4903fbf --- /dev/null +++ b/gnulib/import/filenamecat-lgpl.c @@ -0,0 +1,88 @@ +/* Concatenate two arbitrary file names. + + Copyright (C) 1996-2007, 2009-2016 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 <http://www.gnu.org/licenses/>. */ + +/* Written by Jim Meyering. */ + +#include <config.h> + +/* Specification. */ +#include "filenamecat.h" + +#include <stdlib.h> +#include <string.h> + +#include "dirname.h" + +#if ! HAVE_MEMPCPY && ! defined mempcpy +# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N))) +#endif + +/* Return the longest suffix of F that is a relative file name. + If it has no such suffix, return the empty string. */ + +static char const * _GL_ATTRIBUTE_PURE +longest_relative_suffix (char const *f) +{ + for (f += FILE_SYSTEM_PREFIX_LEN (f); ISSLASH (*f); f++) + continue; + return f; +} + +/* Concatenate two file name components, DIR and ABASE, 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, where BASE is ABASE with any + file system prefixes and leading separators removed. + Arrange for a directory separator if necessary between DIR and BASE + in the result, removing any redundant separators. + In any case, if BASE_IN_RESULT is non-NULL, set + *BASE_IN_RESULT to point to the copy of ABASE in the returned + concatenation. However, if ABASE begins with more than one slash, + set *BASE_IN_RESULT to point to the sole corresponding slash that + is copied into the result buffer. + + Return NULL if malloc fails. */ + +char * +mfile_name_concat (char const *dir, char const *abase, char **base_in_result) +{ + char const *dirbase = last_component (dir); + size_t dirbaselen = base_len (dirbase); + size_t dirlen = dirbase - dir + dirbaselen; + size_t needs_separator = (dirbaselen && ! ISSLASH (dirbase[dirbaselen - 1])); + + char const *base = longest_relative_suffix (abase); + size_t baselen = strlen (base); + + char *p_concat = malloc (dirlen + needs_separator + baselen + 1); + char *p; + + if (p_concat == NULL) + return NULL; + + p = mempcpy (p_concat, dir, dirlen); + *p = DIRECTORY_SEPARATOR; + p += needs_separator; + + if (base_in_result) + *base_in_result = p - IS_ABSOLUTE_FILE_NAME (abase); + + p = mempcpy (p, base, baselen); + *p = '\0'; + + return p_concat; +} |