Newsgroups: comp.parallel.mpi From: Bruce Allen Subject: Re: env-variables & mpich Organization: University of Wisconsin - Milwaukee, Physics Department Date: Mon, 08 Jun 1998 21:58:03 -0500 Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="------------1C217264529A2DC939D71A09" Message-ID: <357CA4BA.F4E175BC@dirac.phys.uwm.edu> --------------1C217264529A2DC939D71A09 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Manfred Krafczyk wrote: > I wonder if there is a way that an executable started via > mpirun -np n executablename > can read the same environment variables that were present > in the shell were mpirun was started. Here's what I use. This is called from every process, right after startup, ie export_environment(node_number,"FIRST_VARIABLE"); export_environment(node_number,"SECOND_VARIABLE"); ... export_environment(node_number,"LAST_VARIABLE"); Cheers, Bruce Allen /* This routine exports environment variables to the nodes */ void export_environment(int node_number,const char *name) { char *environment,*var; int length; /* if this is the master, get enviroment variable */ if (node_number==0) { if (name==NULL) { fprintf(stderr,"Argument to export_environment() can't be null!\n"); fflush(stderr); MPI_Finalize(); exit(1); } if (NULL==(var=getenv(name))) { fprintf(stderr,"Environment variable %s MUST be set!\n",name); fflush(stderr); MPI_Finalize(); exit(1); } /* calculate the length of the string to pass */ length=strlen(name)+strlen(var)+2; } /* broadcast the length of the string */ MPI_Bcast(&length,1,MPI_INT,0,MPI_COMM_WORLD); /* allocate storage for the string */ if (NULL==(environment=(char *)malloc(length))) { fprintf(stderr,"Export_environment() node %d couldn't allocate memory!\n", node_number); fflush(stderr); exit(1); } /* print environment variable into string */ if (node_number==0) { sprintf(environment,"%s=%s",name,var); fprintf(stderr,"Exporting environment variable %s\n",environment); fflush(stderr); } /* then broadcast it to the other processes */ MPI_Bcast(environment,length,MPI_CHAR,0,MPI_COMM_WORLD); /* and put it into the local environment */ if (node_number) { putenv(environment); fprintf(stderr,"Node %d receiving environment variable %s\n", node_number,environment); fflush(stderr); } return; } --------------1C217264529A2DC939D71A09 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Manfred Krafczyk wrote:

I wonder if there is a way that an executable started via
mpirun -np n executablename
can read the same environment variables that were present
in the shell were mpirun was started.

Here's what I use. This is called from every process, right after startup, ie

        export_environment(node_number,"FIRST_VARIABLE");
        export_environment(node_number,"SECOND_VARIABLE");
           ...
        export_environment(node_number,"LAST_VARIABLE");

Cheers,
Bruce Allen

/* This routine exports environment variables to the nodes */
void export_environment(int node_number,const char *name) {
char *environment,*var;
int length;

/* if this is the master, get enviroment variable */
if (node_number==0) {
    if (name==NULL) {
      fprintf(stderr,"Argument to export_environment() can't be null!\n");
      fflush(stderr);
      MPI_Finalize();
      exit(1);

    }
    if (NULL==(var=getenv(name))) {
      fprintf(stderr,"Environment variable %s MUST be set!\n",name);
      fflush(stderr);
      MPI_Finalize();
      exit(1);
    }
    /* calculate the length of the string to pass */
    length=strlen(name)+strlen(var)+2;
}

/* broadcast the length of the string */
MPI_Bcast(&length,1,MPI_INT,0,MPI_COMM_WORLD);

/* allocate storage for the string */
if (NULL==(environment=(char *)malloc(length))) {
    fprintf(stderr,"Export_environment() node %d couldn't allocate memory!\n",
     node_number);
    fflush(stderr);
    exit(1);
}

/* print environment variable into string */
if (node_number==0) {
    sprintf(environment,"%s=%s",name,var);
    fprintf(stderr,"Exporting environment variable %s\n",environment);
    fflush(stderr);
}

/* then broadcast it to the other processes */
MPI_Bcast(environment,length,MPI_CHAR,0,MPI_COMM_WORLD);

/* and put it into the local environment */
if (node_number) {
    putenv(environment);
    fprintf(stderr,"Node %d receiving environment variable %s\n",
     node_number,environment);
    fflush(stderr);
}
return;
}
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