xref: /petsc/src/sys/fileio/grpath.c (revision 5b6bfdb9644f185dbf5e5a09b808ec241507e1e7)
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 
18 /*@C
19    PetscGetRealPath - Get the path without symbolic links etc. and in absolute form.
20 
21    Not Collective
22 
23    Input Parameter:
24 .  path - path to resolve
25 
26    Output Parameter:
27 .  rpath - resolved path
28 
29    Level: developer
30 
31    Notes:
32    rpath is assumed to be of length PETSC_MAX_PATH_LEN.
33 
34    Systems that use the automounter often generate absolute paths
35    of the form "/tmp_mnt....".  However, the automounter will fail to
36    mount this path if it is not already mounted, so we remove this from
37    the head of the line.  This may cause problems if, for some reason,
38    /tmp_mnt is valid and not the result of the automounter.
39 
40    Concepts: real path
41    Concepts: path^real
42 
43 .seealso: PetscGetFullPath()
44 @*/
45 PetscErrorCode  PetscGetRealPath(const char path[],char rpath[])
46 {
47   PetscErrorCode ierr;
48   char           tmp3[PETSC_MAX_PATH_LEN];
49   PetscBool      flg;
50 #if !defined(PETSC_HAVE_REALPATH) && defined(PETSC_HAVE_READLINK)
51   char           tmp1[PETSC_MAX_PATH_LEN],tmp4[PETSC_MAX_PATH_LEN],*tmp2;
52   size_t         N,len,len1,len2;
53   int            n,m;
54 #endif
55 
56   PetscFunctionBegin;
57 #if defined(PETSC_HAVE_REALPATH)
58   if (!realpath(path,rpath)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"realpath()");
59 #elif defined(PETSC_HAVE_READLINK)
60   /* Algorithm: we move through the path, replacing links with the real paths.   */
61   ierr = PetscStrcpy(rpath,path);CHKERRQ(ierr);
62   ierr = PetscStrlen(rpath,&N);CHKERRQ(ierr);
63   while (N) {
64     ierr    = PetscStrncpy(tmp1,rpath,N);CHKERRQ(ierr);
65     tmp1[N] = 0;
66     n       = readlink(tmp1,tmp3,PETSC_MAX_PATH_LEN);
67     if (n > 0) {
68       tmp3[n] = 0; /* readlink does not automatically add 0 to string end */
69       if (tmp3[0] != '/') {
70         ierr    = PetscStrchr(tmp1,'/',&tmp2);CHKERRQ(ierr);
71         ierr    = PetscStrlen(tmp1,&len1);CHKERRQ(ierr);
72         ierr    = PetscStrlen(tmp2,&len2);CHKERRQ(ierr);
73         m       = len1 - len2;
74         ierr    = PetscStrncpy(tmp4,tmp1,m);CHKERRQ(ierr);
75         tmp4[m] = 0;
76         ierr    = PetscStrlen(tmp4,&len);CHKERRQ(ierr);
77         ierr    = PetscStrlcat(tmp4,"/",PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
78         ierr    = PetscStrlcat(tmp4,tmp3,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
79         ierr    = PetscGetRealPath(tmp4,rpath);CHKERRQ(ierr);
80         ierr    = PetscStrlcat(rpath,path+N,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
81       } else {
82         ierr = PetscGetRealPath(tmp3,tmp1);CHKERRQ(ierr);
83         ierr = PetscStrncpy(rpath,tmp1,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
84         ierr = PetscStrlcat(rpath,path+N,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
85       }
86       PetscFunctionReturn(0);
87     }
88     ierr = PetscStrchr(tmp1,'/',&tmp2);CHKERRQ(ierr);
89     if (tmp2) {
90       ierr = PetscStrlen(tmp1,&len1);CHKERRQ(ierr);
91       ierr = PetscStrlen(tmp2,&len2);CHKERRQ(ierr);
92       N    = len1 - len2;
93     } else {
94       ierr = PetscStrlen(tmp1,&N);CHKERRQ(ierr);
95     }
96   }
97   ierr = PetscStrncpy(rpath,path,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
98 #else /* Just punt */
99   ierr = PetscStrcpy(rpath,path);CHKERRQ(ierr);
100 #endif
101 
102   /* remove garbage some automounters put at the beginning of the path */
103   ierr = PetscStrncmp("/tmp_mnt/",rpath,9,&flg);CHKERRQ(ierr);
104   if (flg) {
105     ierr = PetscStrcpy(tmp3,rpath + 8);CHKERRQ(ierr);
106     ierr = PetscStrcpy(rpath,tmp3);CHKERRQ(ierr);
107   }
108   PetscFunctionReturn(0);
109 }
110