1 | /* Construct a full filename from a directory and a relative filename. |
2 | Copyright (C) 2001-2004, 2006-2019 Free Software Foundation, Inc. |
3 | |
4 | This program is free software: you can redistribute it and/or modify it |
5 | under the terms of the GNU General Public License as published by the |
6 | Free Software Foundation; either version 3 of the License, or any |
7 | later version. |
8 | |
9 | This program is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | GNU General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU General Public License |
15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
16 | |
17 | /* Written by Bruno Haible <haible@clisp.cons.org>. */ |
18 | |
19 | #include <config.h> |
20 | |
21 | /* Specification. */ |
22 | #include "concat-filename.h" |
23 | |
24 | #include <errno.h> |
25 | #include <stdlib.h> |
26 | #include <string.h> |
27 | |
28 | #include "filename.h" |
29 | |
30 | /* Concatenate a directory filename, a relative filename and an optional |
31 | suffix. The directory may end with the directory separator. The second |
32 | argument may not start with the directory separator (it is relative). |
33 | Return a freshly allocated filename. Return NULL and set errno |
34 | upon memory allocation failure. */ |
35 | char * |
36 | concatenated_filename (const char *directory, const char *filename, |
37 | const char *suffix) |
38 | { |
39 | char *result; |
40 | char *p; |
41 | |
42 | if (strcmp (directory, "." ) == 0) |
43 | { |
44 | /* No need to prepend the directory. */ |
45 | result = (char *) malloc (strlen (filename) |
46 | + (suffix != NULL ? strlen (suffix) : 0) |
47 | + 1); |
48 | if (result == NULL) |
49 | return NULL; /* errno is set here */ |
50 | p = result; |
51 | } |
52 | else |
53 | { |
54 | size_t directory_len = strlen (directory); |
55 | int need_slash = |
56 | (directory_len > FILE_SYSTEM_PREFIX_LEN (directory) |
57 | && !ISSLASH (directory[directory_len - 1])); |
58 | result = (char *) malloc (directory_len + need_slash |
59 | + strlen (filename) |
60 | + (suffix != NULL ? strlen (suffix) : 0) |
61 | + 1); |
62 | if (result == NULL) |
63 | return NULL; /* errno is set here */ |
64 | memcpy (result, directory, directory_len); |
65 | p = result + directory_len; |
66 | if (need_slash) |
67 | *p++ = '/'; |
68 | } |
69 | p = stpcpy (p, filename); |
70 | if (suffix != NULL) |
71 | stpcpy (p, suffix); |
72 | return result; |
73 | } |
74 | |