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I am having trouble searching a Linked List for contacts, when the program goes to scan in the last name it reads it in over and over. I am wondering why it doesn't just take the name and continue after that? The problems I am having are in the:
void Search(struct contact *ptr) function. Here is the code:
And adding this which I though was the problem just causes it to go through but segment:Code:#include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <string.h> //global: struct contact *ptrFirst = NULL;//empty list (ptrFirst is the head of the list struct contact *ptrLast = NULL;//empty list (ptrLast is the tail of the list) //declare a structure called contact struct contact //contact struct for holding contact info { char firstname[40]; //holds the first name of ith contact char lastname[40]; //holds last name of ith contact char address[100]; //holds address of ith contact char postalcode[7]; //holds postalcode of ith contact char phone[10]; //holds phone of ith contact struct contact *ptrNext; // self referential pointer }; //Prototypes: struct contact *CreateContact(); void PrintList(struct contact *ptr); void ResetList(); struct contact *AddToEnd(struct contact *ptrNew); struct contact* InputRecord(struct contact *ptrNew); // used by Add to interactively get the values from the user int Save(const char* filename); int Load(const char* filename); char *WordCap(char *word); void Search(struct contact *ptr); int i=0; int main() { int run=1; int input=1; int result=0; int count=0; printf("*** Personal Contact Book v1.0 ***"); printf("\n");//newline for neatness while(run==1) { char temp[50]; char again[10]={'Y'}; //if after a contact is entered if will store if user wants to enter another one printf( "1. Add new contact\n" "2. Display current contacts\n" "3. Search for a contact\n" "4. Save contacts to file\n" "6. Delete an existing record\n" "7. Exit\n" ); scanf("%d", &input); fflush(stdin); //flush because scanf was used i=0; switch(input) { case 1: { while(again[0]=='Y') { AddToEnd(InputRecord(CreateContact())); printf("Add another contact?: ");//ask if they want to enter another contact gets(again);//scan in answer again[0]=toupper(again[0]);//make again cap so that it will correctly compare printf("\n");//newline for neatness } break; } case 2: { PrintList(ptrFirst); break; } case 3: { Search(ptrFirst); } case 4: { } case 5: { } case 6: { } case 7: { ResetList(ptrFirst); run = 0; break; } default: { printf("Invalid entry, try again\n\n"); break; } } } } //CreateContact creates using dynamic memory allocation a new record of type contact //Input: assumes enough dynamic memory is available //Output: returns a pointer to the enw contact, or NULL if not enough memory struct contact *CreateContact() { return (struct contact *)(malloc(sizeof(struct contact))); } //PrintList will print out the contents of the list void PrintList(struct contact *ptr) { if(ptr!=NULL) { printf("First name: %s\n",ptr->firstname); printf("Last name : %s\n",ptr->lastname); printf("Address : %s\n",ptr->address); printf("Postal Code: %s\n",ptr->postalcode); printf("Phone : %s\n",ptr->phone);//ask for phone printf("\n");//newline for neatness PrintList(ptr->ptrNext); } } void Search(struct contact *ptr) { char name[40]; printf("What is the contact's last name?: "); gets(name); strcpy(name,WordCap(name)); //copy name back into ith lastname after wordcap opperated on it while(ptr!=NULL) { if(strcmp(name,ptr->lastname)==0) { i++; } ptr->ptrNext; } printf("Found %d record(s):\n", i); } //ResetList will empty or free() the contents of the list void ResetList() { struct contact *ptrDel=ptrFirst; if (ptrDel != NULL) // empty list! nothing to erase... quit { ResetList(ptrDel->ptrNext); free(ptrDel); } } //AddToEnd will add a contact to the end of the list struct contact *AddToEnd(struct contact *ptrNew) { //case 1: ptrNew is not valid(ie. NULL - nothing to add!) if(ptrNew==NULL) return NULL; //case 2: add the record to an empty list if(ptrFirst==NULL) { ptrFirst=ptrNew; ptrLast=ptrNew; } //case 3: add the record to an existing list else { ptrLast->ptrNext = ptrNew; ptrLast = ptrNew; } } //InputRecord sets the initial values of a new record //Input: a pointer to an existing record //Output: sets the int value to a value from the keyboard, and null to all pointers // and returns the same pointer to that initialized record struct contact* InputRecord(struct contact *ptrNew) { if(ptrNew==NULL) //fail-safe: check for valid pointer return NULL; int valid=0; //used when determining if user entered a valid phone or postalcode printf("First name: "); gets(ptrNew->firstname); strcpy(ptrNew->firstname,WordCap(ptrNew->firstname)); //copy word back into ith firstname after wordcap opperated on it printf("Last name : "); gets(ptrNew->lastname); strcpy(ptrNew->lastname,WordCap(ptrNew->lastname)); //copy word back into ith lastname after wordcap opperated on it printf("Address : "); gets(ptrNew->address); printf("PostalCode: "); gets(ptrNew->postalcode); while(valid==0) //while not valid { //if all the correct positions are words and numbers respectivly it will become valid if(isalpha(ptrNew->postalcode[0]) && isdigit(ptrNew->postalcode[1]) && isalpha(ptrNew->postalcode[2]) && isdigit(ptrNew->postalcode[3]) && isalpha(ptrNew->postalcode[4]) && isdigit(ptrNew->postalcode[5])) { valid=9; //update valid if it is valid } else { printf("Invalid please re-enter PostalCode: "); //else tell user not valid gets(ptrNew->postalcode);//scan in again to get new postal code } } printf("Phone : ");//ask for phone gets(ptrNew->phone);//scan in phone valid=0;//assume not valid while(valid==0)//while not valid { //check if it is all digits if(isdigit(ptrNew->phone[0]) && isdigit(ptrNew->phone[1]) && isdigit(ptrNew->phone[2]) && isdigit(ptrNew->phone[3]) && isdigit(ptrNew->phone[4]) && isdigit(ptrNew->phone[5]) && isdigit(ptrNew->phone[6]) && isdigit(ptrNew->phone[7]) && isdigit(ptrNew->phone[8]) && isdigit(ptrNew->phone[9])) { valid=9;//update validity } else { printf("Invalid please re-enter Phone: ");//else print not valid gets(ptrNew->phone);//re scan in phone } } ptrNew->ptrNext=NULL; return ptrNew; } char *WordCap(char *word) { int i=1; //keeps track of how far in the word it is *word=toupper(*word); //capatalize the first char while(*(word+i)!='\0') //while not the end of the word { *(word+i)=tolower(*(word+i)); //it will make the rest lower case i++; //increment i } *(word+i)=tolower(*(word+i)); //it will make the rest lower case return word; //return now capatalized }
ptr=ptr->ptrNext;
. You should also go through your code and replace all of the gets() with fgets() and remove the fflush(stdin) calls. The gets function is very dangerous because it is easy to overrun the array bounds. The fflush() function is not defined for input streams, it only works for output streams.