Writing user commands
The access to user written subroutines is through the LaGriT subroutine, user_sub. It is passed the parsed command input line. The parser breaks up the input line into tokens and returns to LaGriT a count of number of tokens, an array containing the token types, and the tokens themselves. The parameters returned by the parser are: nwds ( number of tokens)
msgtyp (integer array of token types : 1 for integer, 2 for real, 3 for character, msgtyp(nwds+1) = -1)
imsgin (array of integer tokens, e.g. if msgtyp(i)=1 then the ith token is type integer and imsgin(i) contains its value)
xmsgin (array of real tokens, e.g. if msgtyp(i)=2 then the ith token is type real and xmsgin(i) contains its value)
cmsgin (array of character tokens, e.g. if msgtyp(i)=3 then the ith token is type character and cmsgin(i) contains its value)Null fields are given the integer value 0, real value 0, and character value '-def-'. If the user has written a subroutine, my_routine,that responds to the command, my_comnd, the call from user_sub should look like: elseif (cmsgin(1).eq. 'my_comnd')  x           call my_routine(nwds,imsgin,xmsgin,cmsgin,msgtyp,ierr1)
The subroutine my_routine should set ierr1 to zero if the command is processed successfully and should use the cmo interface routines to access the components of the Mesh Object that it needs, for example:  
       subroutine my_routine(nwds,imsgin,xmsgin,cmsgin,msgtyp,ierr1)
      integer nwds, imsgin(*),msgtyp(*),ierr1
      real xmsgin(*)
      character*32 cmsgin(*)
        ....      character*32 cmo
      pointer (ipimt1, imt1(*))
      integer ierror,ilen,ityp,nnodes
c get the name of the current mesh object
      call cmo_get_name(cmo_name,ierror)
c get the number of nodes and the material ids
      call cmo_get_intinfo('nnodes',cmo_name,nnodes,ilen,ityp,ierror)
      call cmo_get_info('imt1',cmo_name,ipimt1,ilen,ityp,ierror)
 LaGriT will check it's internal command list and if the input command is not found it will call user_sub.  If user_sub does not find the command, LaGriT will issue  the error message: 'Illegal command' and continue with the next command.
An empty user_sub is distributed with the sample driver program contained in the file adrivgen.f