Actual source code: grpath.c

petsc-main 2021-03-01
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  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.


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

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

100:   /* remove garbage some automounters put at the beginning of the path */
101:   PetscStrncmp("/tmp_mnt/",rpath,9,&flg);
102:   if (flg) {
103:     PetscStrcpy(tmp3,rpath + 8);
104:     PetscStrcpy(rpath,tmp3);
105:   }
106:   return(0);
107: }