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130 lines
3.1 KiB
C
130 lines
3.1 KiB
C
/* path-concat.c -- concatenate two arbitrary pathnames
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Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free
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Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Written by Jim Meyering. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#ifndef HAVE_MEMPCPY
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# define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N)))
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#endif
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#include <stdio.h>
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#if HAVE_STRING_H
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# if !STDC_HEADERS && HAVE_MEMORY_H
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# include <memory.h>
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# endif
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# include <string.h>
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#else
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# if HAVE_STRINGS_H
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# include <strings.h>
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# endif
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#endif
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#if HAVE_STDLIB_H
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# include <stdlib.h>
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#endif
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#if HAVE_UNISTD_H
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# include <unistd.h>
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#endif
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#ifndef HAVE_DECL_MALLOC
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"this configure-time declaration test was not run"
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#endif
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#if !HAVE_DECL_MALLOC
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char *malloc ();
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#endif
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#ifndef strdup
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char *strdup ();
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#endif
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#include "dirname.h"
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#include "xalloc.h"
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#include "path-concat.h"
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/* Concatenate two pathname components, DIR and BASE, in
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newly-allocated storage and return the result. Return 0 if out of
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memory. Add a slash between DIR and BASE in the result if neither
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would contribute one. If each would contribute at least one, elide
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one from the end of DIR. Otherwise, simply concatenate DIR and
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BASE. In any case, if BASE_IN_RESULT is non-NULL, set
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*BASE_IN_RESULT to point to the copy of BASE in the returned
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concatenation.
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DIR may be NULL, BASE must not be.
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Return NULL if memory is exhausted. */
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char *
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path_concat (const char *dir, const char *base, char **base_in_result)
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{
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char *p;
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char *p_concat;
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size_t baselen;
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size_t dirlen;
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if (!dir)
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{
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p_concat = strdup (base);
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if (base_in_result)
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*base_in_result = p_concat;
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return p_concat;
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}
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/* DIR is not empty. */
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baselen = base_len (base);
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dirlen = strlen (dir);
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p_concat = malloc (dirlen + baselen + 2);
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if (!p_concat)
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return 0;
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p = mempcpy (p_concat, dir, dirlen);
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if (FILESYSTEM_PREFIX_LEN (dir) < dirlen)
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{
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if (ISSLASH (*(p - 1)) && ISSLASH (*base))
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--p;
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else if (!ISSLASH (*(p - 1)) && !ISSLASH (*base))
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*p++ = DIRECTORY_SEPARATOR;
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}
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if (base_in_result)
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*base_in_result = p;
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memcpy (p, base, baselen);
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p[baselen] = '\0';
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return p_concat;
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}
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/* Same, but die when memory is exhausted. */
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char *
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xpath_concat (const char *dir, const char *base, char **base_in_result)
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{
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char *res = path_concat (dir, base, base_in_result);
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if (! res)
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xalloc_die ();
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return res;
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}
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