Command Line Program - Sending 'Enter' commands - command-line

Question

I have command line program that has a menu with multiple choice. I can pass the parameter via program.exe < input.txt but I am having problems sending the 'Enter' command (the program crashes if I attempt to send anything else; such as a ' ' character).
I enter 'All' as Proc name. It then prints 'enter proc name' again and I have to hit Enter for the code to continue. What I cannot work out is how to send this Enter to the program. I have tried a black line in input.txt but that did not work.
while( !end )
{
for( legal=0; !legal; )
{
printf("\tEnter Proc Name: ");
if( fgets( str, 70, stdin ) == NULL )
{
printf("Bye.\n");
exit(0);
}
ret = sscanf(str, "%s", p.name );
if( ret > 0 || str[0] == '\n' ) legal = 1;
else printf("Please enter a legal proc name, none, or all\n");
}
if( str[0] == '\n' ) {
end = 1;
} else if( !strcmp( p.name, "all" )) {
for( i=0; i < Conf_num_procs( &Cn ); i++ )
Status_vector[i] = 1;
} else if( !strcmp( p.name, "none" )) {
for( i=0; i < Conf_num_procs( &Cn ); i++ )
Status_vector[i] = 0;
} else {
proc_index = Conf_proc_by_name( p.name, &p );
if( proc_index != -1 ) {
Status_vector[proc_index] = 1;
} else printf("Please! enter a legal proc name, none, or all\n");
}
}