how to run and give input to the following program?

/* convert cvs data to libsvm/svm-light format */
include 
include 
include 

char buf[10000000];
float feature[100000];
int main(int argc, char **argv)
{
FILE *fp;

if(argc!=2)
 { 
fprintf(stderr,"Usage %s filename\n",argv[0]); 
}

if((fp=fopen(argv[1],"r"))==NULL)
{
fprintf(stderr,"Can't open input file %s\n",argv[1]);

}
while(fscanf(fp,"%[^\n]\n",buf)==1)
{
int i=0,j;

char *p=strtok(buf,",");
feature[i++]=atof(p);

while((p=strtok(NULL,",")))

        feature[i++]=atof(p);


//      --i;
    /*

if ((int) feature[i]==1)
printf("-1 ");
else
printf("+1 ");
    */
    //  
printf("%f ", feature[1]);

    printf("%d ", (int) feature[0]);

    for(j=1;j<i;j++)

        printf(" %d:%f",j,feature[j]);



printf("\n");

}
return 0;

}