void main(){

FILE *fp1;
int i,ii,iii=0,j,jj;
char I[BUF_SIZE],M[BUF_SIZE],E[BUF_SIZE];
fp1=fopen("DATA.txt","r");

char line[BUF_SIZE];
while( fgets(line,sizeof(line),fp1) != NULL ) {
char *s = line;
line[strlen(line)-1] = '\0';
if( *s++ == '>' ){
if (*s++ != '>') {
strcpy(I, line);
} else if (*s++ != '>') {
strcpy(M, line);
} else {
strcpy(E, line);
}
}
この続きはどうなってるの？