Thread: Memory access violation

The following code compiles, but when I try to run case 4 from main() (the search function), my program crashes. Debugging tells me that "An access violation (segmentation fault) raised in" my program. I understand that this is a memory access violation, but I'm not sure why; I've commented most of the parts in the first case of the findEntry() function out, but still get the problem. Any ideas what's causing my memory access problem? Thanks for any and all help.

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>

/* Prototypes */
void addEntry(void);
void delEntry(int);
void dispBook(int);
void sortBook(void);
void findEntry(void);
void dispEntry(int);
void delBook(void);
void capName(int);
int  random(int);

/*------------*/

/* Globals */

int total=0; //last record available

typedef struct Entry {
        char firstName[20];
        char lastName[20];
        char phoneNum[20];
        } newEntry;

        newEntry *bookList;

/*----------*/
        
int main() { //display menu
    
       int choice; //menu selection
             
       system("cls");
       printf("\n\n\nPhone Book Application - Menu");
       printf("\n\t1. Add a contact");
       printf("\n\t2. Display contacts");
       printf("\n\t3. Sort contacts");
       printf("\n\t4. Find a contact");
       printf("\n\t5. Choose random contact");
       printf("\n\t6. Delete all contacts");
       printf("\n\t7. Exit");
       
       printf("\n\n Enter a selection: ");
       scanf("%d" , &choice);
       
       switch (choice) {
              
              case 1:
                   addEntry();
                   break;
              case 2:
                   dispBook(total);
                   break;
              case 3:
                   //sortBook();
                   break;
              case 4:
                   findEntry();
                   break;
              case 5:
                   if( total != 0 ) {
                       srand(time(NULL));
                       dispEntry(rand() % total);
                       }
                   else {
                        printf("\n\nNo entries found!\n\n");
                        system("pause");
                        main();
                        }
                   break;
              case 6:
                   delBook();
                   break;
              case 7:
                   printf("\n\nGoodbye!\n\n");
                   system("pause");
                   break;
              default:
                      printf("\n\n\t\tInvalid selection! Try again.");
                      main(); return 0;
              } //end switch
              } //end main
              
void addEntry() {
     if ( total == 0 ) {
          bookList=(newEntry*) malloc(sizeof(newEntry));
          }
     else {
          bookList=(newEntry*) realloc(bookList,(total+1)*sizeof(newEntry));
          }

     system("cls");
     printf("\n\nAdd an entry");
     printf("\n\nEnter first name: ");
     scanf("%s" , bookList[total].firstName);
     printf("\nEnter last name: ");
     scanf("%s" , bookList[total].lastName);
     printf("\nEnter phone number: ");
     scanf("%s" , bookList[total].phoneNum);
     capName(total);
     printf("\n\nRecord added to phone book.\n\n");
     total++;
     system("pause");
     main();
     } //end def
              
void delEntry(int entry) {
    int i;
    if ( (total!=(entry+1))) {
    for( i=entry; i<total; i++ ) {
         bookList[i]=bookList[1+i];
         }//end for
         }//end if
         
    free(bookList+total-1); 
    if(total!=0) {
         total--;
         } //end if
    dispBook(total);
    } //end def

       
void dispBook(int total) {
     
     system("cls");
     if ( total != 0 ) {
          if ( total == 1)
          printf("\n\n%d phone book entry:" , total);
          if ( total > 1)
          printf("\n\n%d phone book entries:" , total);
         int i;
         for( i=0; (i+1)<=total; i++ ) {
              printf("\n\nID: %d" , i+1);
              printf("\nName: %s %s" , bookList[i].firstName, bookList[i].lastName);
              printf("\nPhone number: %s" , bookList[i].phoneNum);
              } //end loop
              printf("\n\n");
              
         printf("To delete an entry, enter its ID #,\nor enter 0 to return to the menu.\t");
         int entry; scanf("%d" , &entry);
         
         if (entry == 0)
            { main(); }
         else { 
              if ( entry>0 && entry <= total)
              delEntry(entry-1); 
              else {
                   printf("\n\n\t\tInvalid input! Try again.\n\n"); 
                   system("pause");
                   dispBook(total);
                   }//end else
                   }//end else
               }//end if
     else {
          printf("\n\nNo entries found!\n\n");
          system("pause");
          main();
          } //end else
          } //end def
          
/*void sortBook(void) {
     int i;
     newEntry temp;
     for( i=0; i<=total; i++ ) {
          
}*/

void findEntry(void) {
     system("cls");
     int sChoice;
     char *searchName;
     printf("\nSearch for an entry:");
     printf("\n\t1. by last name");
     printf("\n\t2. by first name");
     printf("\n\n\t3. Back to menu");
     printf("\n\nEnter a selection: ");
     scanf("%d" , &sChoice);
     
     switch(sChoice) {
                     case 1:
                          system("cls");
                          printf("\nEnter last name: ");
                          scanf("%s" , searchName);
                          
                          int u;
                          for ( u=0; u < strlen(searchName); u++ )
                              searchName[u] = tolower(searchName[u]);
                          
                          int i, x=0;
                          for( i=0; i<total; i++ ) { //I suspect that the problem is in this area
                               if (strcmp(bookList[i].lastName, searchName) == 1) {
                                  dispEntry(i); 
                                  x++; 
                                  }
                                  }
                          if ( x==0 ) {
                             printf("No entry found!");}
                             system("pause");
                             main();
                          break;
                     case 2:
                          system("cls");
                          printf("\nEnter first name: ");
                          scanf("%s" , searchName);
                          
                          for ( u=0; u <= strlen(searchName); u++ )
                              searchName[u] = tolower(searchName[u]);
                          
                          for( i=0; i<=total; i++ ) {
                               if (strcmp(bookList[i].firstName, searchName) == 1) {
                                  dispEntry(i); 
                                  x++; 
                                  }
                                  }
                          if ( x==0 ) {
                             printf("No entry found!"); }
                             system("pause");
                             main(); 
                          break;
                     case 3:
                          main(); break;
                     default:
                             printf("\n\n\t\tInvalid selection! Try again.");
                             findEntry();
                     } //end of switch
                     } //end of def
                                                       
                           

void dispEntry(int toDisp) {
     
     system("cls");
          printf("\n\nID: %d" , toDisp+1);
          printf("\nName: %s %s" , bookList[toDisp].firstName, bookList[toDisp].lastName);
          printf("\nPhone number: %s" , bookList[toDisp].phoneNum);
          printf("\n\n");
          
     printf("To delete this entry, enter its ID #,\nor enter 0 to return to the menu.\t");
     int entry; scanf("%d" , &entry);
     
     if (entry == 0)
        { main(); }
     else { 
          if ( entry==toDisp )
          delEntry(entry-1); 
          else {
               printf("\n\n\t\tInvalid input! Try again.\n\n"); 
               system("pause");
               dispBook(total);
               }//end else
               }//end else
          } //end def

void delBook(void) {
     int i;
     for( i=0; i<=total; i++ ) {
          free(bookList+i);
          }
     total = 0;
     main();
     }
     

void capName(int change) {
     
     bookList[change].firstName[0]=toupper(bookList[change].firstName[0]);
     bookList[change].lastName[0] =toupper(bookList[change].lastName[0]);
     }

You might like to try allocating memory for *searchname.

1P: Thank you... I don't know where I got that you could declare a string that way... I could've sworn I'd seen it done that way. Maybe I'm mixing array notation with declaring as a pointer and then initializing recursively...

Anyway, thanks again.

2P: I don't want to run the menu recursively (a set number of times). I only return to menu when there's an error or when my individual functions have performed their duties. How else could I display the menu again after one function of it has been performed?

Thanks for the help, guys.