C simple DVD shop

#include 
#include 
#include 
#include "dvdTracker2.h"


/**************************************************> main <*/
int main (int argc, const char * argv[]) {
 char   command;
 
 gHeadPtr = NULL;
 gTailPtr = NULL;
 
 while ( (command = GetCommand() ) != 'q' ) {
  switch( command ) {
   case 'n':
    AddToList( ReadStruct() );
    break;
   case 'l':
    ListDVDs();
    break;
  }
 }
 
 printf( "Goodbye..." );
 
 return 0;
}


/*******************************************> GetCommand <*/
char GetCommand( void )
{
 char command;
 
 do {
  printf( "Enter command (q=quit, n=new, l=list):  " );
  scanf( "%c", &command );
  Flush();
 }
 while ( (command != 'q') && (command != 'n')
           && (command != 'l') );
 
 printf( "\n----------\n" );
 return( command );
}


/*******************************************> ReadStruct <*/
struct DVDInfo *ReadStruct( void ) {
 struct DVDInfo *infoPtr;
 int    num;
 
 infoPtr = (struct DVDInfo *)malloc( sizeof( struct DVDInfo ) );
 
 if ( NULL == infoPtr ) {
  printf( "Out of memory!!!  Goodbye!\n" );
  exit( 0 );
 }
 
 printf( "Enter DVD Title:  " );
 fgets( infoPtr->title, kMaxTitleLength, stdin );
 ReplaceReturnAtEndOfString( infoPtr->title );
 
 printf( "Enter DVD Comment:  " );
 fgets( infoPtr->comment, kMaxCommentLength, stdin );
 ReplaceReturnAtEndOfString( infoPtr->comment );
 
 do {
  num = 0;
        printf( "Enter DVD Rating (1-10):  " );
  scanf( "%d", &num );
  Flush();
 }
 while ( ( num < 1 ) || ( num > 10 ) );
 
 infoPtr->rating = num;
 
 printf( "\n----------\n" );
 
 return( infoPtr );
}


/*******************************************> AddToList <*/
void AddToList( struct DVDInfo *curPtr ) {
 struct DVDInfo *beforePtr;
    
 /* First check to see if the list is empty */
 if ( gHeadPtr == NULL )
  InsertInList( NULL, curPtr );
 else if ( curPtr->rating <= gHeadPtr->rating )
    /* Next check to see if curPtr should be the new first item */
  InsertInList( NULL, curPtr );
 else {
    /* Walk through the list till you find the first rating higher than us */
  beforePtr = gHeadPtr;
  
  while ( (beforePtr->next != NULL) &&
               (beforePtr->next->rating < curPtr->rating) ) {
   beforePtr = beforePtr->next;
  }
  InsertInList( beforePtr, curPtr );
 }
}


/*******************************************> InsertInList <*/
void InsertInList( struct DVDInfo *afterMeDVDPtr, struct DVDInfo *newDVDPtr )
{
 if ( afterMeDVDPtr == NULL ) {
    /* This means we want to insert the new one as the first in the list */
  newDVDPtr->next = gHeadPtr;
  gHeadPtr = newDVDPtr;
  if ( gTailPtr == NULL )
   gTailPtr = newDVDPtr;
 }
 else if ( afterMeDVDPtr == gTailPtr ) {
    /* This means we want to insert the new one as the last in the list */
  gTailPtr->next = newDVDPtr;
  newDVDPtr->next = NULL;
  gTailPtr = newDVDPtr;
 }
 else {
  newDVDPtr->next = afterMeDVDPtr->next;
  afterMeDVDPtr->next = newDVDPtr;
 }
}


/*******************************************> ListDVDs <*/
void ListDVDs( void ) {
 struct DVDInfo *curPtr;
 
 if ( NULL == gHeadPtr ) {
  printf( "No DVDs have been entered yet...\n" );
  printf( "\n----------\n" );
 } else {
  for ( curPtr=gHeadPtr; curPtr!=NULL; curPtr = curPtr->next ) {
   printf( "Title:  %s\n", curPtr->title );
   printf( "Comment:   %s\n", curPtr->comment );
   printf( "Rating:  %d\n", curPtr->rating );
   
   printf( "\n----------\n" );
  }
 }
}


/***********************> ReplaceReturnAtEndOfString <*/
void    ReplaceReturnAtEndOfString( char *theString ) {
    int    length = strlen( theString );
    
    theString[ length - 1 ] = '\0';
}


/*******************************************> Flush <*/
void Flush( void ) {
 while ( getchar() != '\n' )
  ;
}