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a63c7fa1 | 1 | /* Find path of executable. |
f7a9f785 | 2 | Copyright (C) 1998-2016 Free Software Foundation, Inc. |
a63c7fa1 CM |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
ab84e3ff PE |
17 | License along with the GNU C Library. If not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
a63c7fa1 CM |
19 | |
20 | #include <assert.h> | |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
23 | #include <unistd.h> | |
24 | #include <fcntl.h> | |
25 | #include <sys/param.h> | |
26 | #include <ldsodefs.h> | |
27 | #include <sysdep.h> | |
28 | ||
29 | #include <dl-dst.h> | |
30 | ||
31 | /* On Linux >= 2.1 systems which have the dcache implementation we can get | |
32 | the path of the application from the /proc/self/exe symlink. Try this | |
33 | first and fall back on the generic method if necessary. */ | |
34 | ||
35 | const char * | |
36 | _dl_get_origin (void) | |
37 | { | |
38 | char linkval[PATH_MAX]; | |
39 | char *result; | |
40 | int len; | |
41 | INTERNAL_SYSCALL_DECL (err); | |
42 | ||
43 | len = INTERNAL_SYSCALL (readlinkat, err, 4, AT_FDCWD, "/proc/self/exe", | |
44 | linkval, sizeof (linkval)); | |
45 | if (! INTERNAL_SYSCALL_ERROR_P (len, err) && len > 0 && linkval[0] != '[') | |
46 | { | |
47 | /* We can use this value. */ | |
48 | assert (linkval[0] == '/'); | |
49 | while (len > 1 && linkval[len - 1] != '/') | |
50 | --len; | |
51 | result = (char *) malloc (len + 1); | |
52 | if (result == NULL) | |
53 | result = (char *) -1; | |
54 | else if (len == 1) | |
55 | memcpy (result, "/", 2); | |
56 | else | |
57 | *((char *) __mempcpy (result, linkval, len - 1)) = '\0'; | |
58 | } | |
59 | else | |
60 | { | |
61 | result = (char *) -1; | |
62 | /* We use the environment variable LD_ORIGIN_PATH. If it is set make | |
63 | a copy and strip out trailing slashes. */ | |
64 | if (GLRO(dl_origin_path) != NULL) | |
65 | { | |
66 | size_t len = strlen (GLRO(dl_origin_path)); | |
67 | result = (char *) malloc (len + 1); | |
68 | if (result == NULL) | |
69 | result = (char *) -1; | |
70 | else | |
71 | { | |
72 | char *cp = __mempcpy (result, GLRO(dl_origin_path), len); | |
73 | while (cp > result + 1 && cp[-1] == '/') | |
74 | --cp; | |
75 | *cp = '\0'; | |
76 | } | |
77 | } | |
78 | } | |
79 | ||
80 | return result; | |
81 | } |