Actual source code: grpath.c

  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

 18: /*@C
 19:    PetscGetRealPath - Get the path without symbolic links etc. and in absolute form.

 21:    Not Collective

 23:    Input Parameter:
 24: .  path - path to resolve

 26:    Output Parameter:
 27: .  rpath - resolved path

 29:    Level: developer

 31:    Notes:
 32:    rpath is assumed to be of length `PETSC_MAX_PATH_LEN`.

 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.

 40: .seealso: `PetscGetFullPath()`
 41: @*/
 42: PetscErrorCode PetscGetRealPath(const char path[], char rpath[])
 43: {
 44:   char      tmp3[PETSC_MAX_PATH_LEN];
 45:   PetscBool flg;
 46: #if !defined(PETSC_HAVE_REALPATH) && defined(PETSC_HAVE_READLINK)
 47:   char   tmp1[PETSC_MAX_PATH_LEN], tmp4[PETSC_MAX_PATH_LEN], *tmp2;
 48:   size_t N, len, len1, len2;
 49:   int    n, m;
 50: #endif

 52: #if defined(PETSC_HAVE_REALPATH)
 54: #elif defined(PETSC_HAVE_READLINK)
 55:   /* Algorithm: we move through the path, replacing links with the real paths.   */
 56:   PetscStrcpy(rpath, path);
 57:   PetscStrlen(rpath, &N);
 58:   while (N) {
 59:     PetscStrncpy(tmp1, rpath, N);
 60:     tmp1[N] = 0;
 61:     n       = readlink(tmp1, tmp3, PETSC_MAX_PATH_LEN);
 62:     if (n > 0) {
 63:       tmp3[n] = 0; /* readlink does not automatically add 0 to string end */
 64:       if (tmp3[0] != '/') {
 65:         PetscStrchr(tmp1, '/', &tmp2);
 66:         PetscStrlen(tmp1, &len1);
 67:         PetscStrlen(tmp2, &len2);
 68:         m = len1 - len2;
 69:         PetscStrncpy(tmp4, tmp1, m);
 70:         tmp4[m] = 0;
 71:         PetscStrlen(tmp4, &len);
 72:         PetscStrlcat(tmp4, "/", PETSC_MAX_PATH_LEN);
 73:         PetscStrlcat(tmp4, tmp3, PETSC_MAX_PATH_LEN);
 74:         PetscGetRealPath(tmp4, rpath);
 75:         PetscStrlcat(rpath, path + N, PETSC_MAX_PATH_LEN);
 76:       } else {
 77:         PetscGetRealPath(tmp3, tmp1);
 78:         PetscStrncpy(rpath, tmp1, PETSC_MAX_PATH_LEN);
 79:         PetscStrlcat(rpath, path + N, PETSC_MAX_PATH_LEN);
 80:       }
 81:       return 0;
 82:     }
 83:     PetscStrchr(tmp1, '/', &tmp2);
 84:     if (tmp2) {
 85:       PetscStrlen(tmp1, &len1);
 86:       PetscStrlen(tmp2, &len2);
 87:       N = len1 - len2;
 88:     } else {
 89:       PetscStrlen(tmp1, &N);
 90:     }
 91:   }
 92:   PetscStrncpy(rpath, path, PETSC_MAX_PATH_LEN);
 93: #else /* Just punt */
 94:   PetscStrcpy(rpath, path);
 95: #endif

 97:   /* remove garbage some automounters put at the beginning of the path */
 98:   PetscStrncmp("/tmp_mnt/", rpath, 9, &flg);
 99:   if (flg) {
100:     PetscStrcpy(tmp3, rpath + 8);
101:     PetscStrcpy(rpath, tmp3);
102:   }
103:   return 0;
104: }