1 #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for realpath() */
2 #include <petscsys.h>
3 #if defined(PETSC_HAVE_PWD_H)
4 #include <pwd.h>
5 #endif
6 #include <ctype.h>
7 #include <sys/stat.h>
8 #if defined(PETSC_HAVE_UNISTD_H)
9 #include <unistd.h>
10 #endif
11 #if defined(PETSC_HAVE_SYS_UTSNAME_H)
12 #include <sys/utsname.h>
13 #endif
14 #if defined(PETSC_HAVE_SYS_SYSTEMINFO_H)
15 #include <sys/systeminfo.h>
16 #endif
17 #include <errno.h>
18
19 /*@C
20 PetscGetRealPath - Get the path without symbolic links etc. in absolute form.
21
22 Not Collective
23
24 Input Parameter:
25 . path - path to resolve
26
27 Output Parameter:
28 . rpath - resolved path
29
30 Level: developer
31
32 Notes:
33 `rpath` is assumed to be of length `PETSC_MAX_PATH_LEN`.
34
35 Systems that use the automounter often generate absolute paths
36 of the form "/tmp_mnt....". However, the automounter will fail to
37 mount this path if it is not already mounted, so we remove this from
38 the head of the line. This may cause problems if, for some reason,
39 /tmp_mnt is valid and not the result of the automounter.
40
41 .seealso: `PetscGetFullPath()`
42 @*/
PetscGetRealPath(const char path[],char rpath[])43 PetscErrorCode PetscGetRealPath(const char path[], char rpath[])
44 {
45 #if !defined(PETSC_HAVE_REALPATH) && defined(PETSC_HAVE_READLINK)
46 char tmp1[PETSC_MAX_PATH_LEN], char tmp3[PETSC_MAX_PATH_LEN], tmp4[PETSC_MAX_PATH_LEN], *tmp2;
47 size_t N, len1, len2;
48 int n, m;
49 #endif
50 size_t len;
51
52 PetscFunctionBegin;
53 #if defined(PETSC_HAVE_REALPATH)
54 PetscCheck(realpath(path, rpath), PETSC_COMM_SELF, PETSC_ERR_LIB, "Error in realpath() due to \"%s\"", strerror(errno));
55 #else
56 #if defined(PETSC_HAVE_READLINK)
57 /* Algorithm: we move through the path, replacing links with the real paths. */
58 PetscCall(PetscStrlen(path, &N));
59 PetscCall(PetscStrncpy(rpath, path, N + 1)); /* assuming adequate buffer */
60 PetscCall(PetscStrlen(rpath, &N));
61 while (N) {
62 PetscCall(PetscStrncpy(tmp1, rpath, N));
63 tmp1[N] = 0;
64 n = readlink(tmp1, tmp3, PETSC_MAX_PATH_LEN);
65 PetscCheck(n > -1, PETSC_COMM_SELF, PETSC_ERR_SYS, "Error in readlink() due to \"%\"", strerror(errno));
66 if (n > 0) {
67 tmp3[n] = 0; /* readlink does not automatically add 0 to string end */
68 if (tmp3[0] != '/') {
69 PetscCall(PetscStrchr(tmp1, '/', &tmp2));
70 PetscCall(PetscStrlen(tmp1, &len1));
71 PetscCall(PetscStrlen(tmp2, &len2));
72 m = len1 - len2;
73 PetscCall(PetscStrncpy(tmp4, tmp1, m));
74 tmp4[m] = 0;
75 PetscCall(PetscStrlen(tmp4, &len));
76 PetscCall(PetscStrlcat(tmp4, "/", PETSC_MAX_PATH_LEN));
77 PetscCall(PetscStrlcat(tmp4, tmp3, PETSC_MAX_PATH_LEN));
78 PetscCall(PetscGetRealPath(tmp4, rpath));
79 PetscCall(PetscStrlcat(rpath, path + N, PETSC_MAX_PATH_LEN));
80 } else {
81 PetscCall(PetscGetRealPath(tmp3, tmp1));
82 PetscCall(PetscStrncpy(rpath, tmp1, PETSC_MAX_PATH_LEN));
83 PetscCall(PetscStrlcat(rpath, path + N, PETSC_MAX_PATH_LEN));
84 }
85 PetscFunctionReturn(PETSC_SUCCESS);
86 }
87 PetscCall(PetscStrchr(tmp1, '/', &tmp2));
88 if (tmp2) {
89 PetscCall(PetscStrlen(tmp1, &len1));
90 PetscCall(PetscStrlen(tmp2, &len2));
91 N = len1 - len2;
92 } else {
93 PetscCall(PetscStrlen(tmp1, &N));
94 }
95 }
96 #endif
97 PetscCall(PetscStrncpy(rpath, path, PETSC_MAX_PATH_LEN)); /* assuming adequate buffer */
98 #endif
99
100 /* remove garbage some automounters put at the beginning of the path */
101 {
102 const char garbage[] = "/tmp_mnt/";
103 const size_t garbage_len = sizeof(garbage) - 1; // 9
104 PetscBool flg;
105
106 PetscCall(PetscStrncmp(garbage, rpath, garbage_len, &flg));
107 if (flg) {
108 const size_t no_slash_len = garbage_len - 1; // 8
109
110 PetscCall(PetscStrlen(rpath, &len));
111 // shift the array left by no_slash_len
112 PetscCall(PetscArraymove(rpath, rpath + no_slash_len, len - no_slash_len));
113 // zero out the end we just moved from
114 PetscCall(PetscArrayzero(rpath + len - no_slash_len, no_slash_len));
115 }
116 }
117 PetscFunctionReturn(PETSC_SUCCESS);
118 }
119