undefined reference to a function

[ChoCo]

This is an unfinished file name immigration.c

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

#include "structure.h"
#include "modifyImmigration.h"

int main(int argc,char* argv[])
{
    int status = 0;
    char buffer[64];
    char codeString[64];
    DATA_T person[100];
    int check;
    char *newValue;
    int index;
    int modify;

    while(status != 6)
        {
        printf("\n\t\t    =========================================\n");
        printf("\n\t\t\tWelcome to Immigration Database!!\n\n");
        printf("\t\t    =========================================\n");
        printf("\t\t\t    Choose what you want to do:\n");
        printf("\t\t    =========================================\n\n");
        printf("\t\t\t    1)Display all records\n");
        printf("\t\t\t    2)Search an existing record\n");
        printf("\t\t\t    3)Add a new record\n");
        printf("\t\t\t    4)Modify an existing record\n");
        printf("\t\t\t    5)Delete an existing record\n");
        printf("\t\t\t    6)Exit the program\n");
        printf("\n\t\t    =========================================\n");


        printf("\n\t\t    Press 1,2,3,4,5 or 6: ");
        fgets(buffer,64,stdin);
        sscanf(buffer,"%d",&status);

        if(status == 1)
            {

            }
        else if(status == 2)
            {
            }
        else if(status == 3)
            {
            }
        else if(status == 4)
            {
            Edit(argc, argv, newValue, index, modify, person);
            }
        else if(status == 5)
            {
            }
        else if(status == 6)
            {
            printf("\n\n\t\t    =========================================");
            printf("\n\t\t        Thank you for using our program :)");
            printf("\n\t\t    =========================================");
            exit(0);
            }
        else
            {
            printf("\nError! Please type in the number between 1 to 6.\n");
            }
        }
}

This is modifyImmigration.c

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

#include "structure.h"

void Edit(int argc, char* argv[], char *newValue, int index, int modify, DATA_T person[100])
{
    char* inputFile;                 /*Pointer inputFile*/
    char* outputFile;                /*Pointer outputFile*/
    char inputBuffer[128];
    int i = 0;
    int j = 0;
    int line = 0;

    FILE* pInfile = NULL;            /*Set pInfile to be NULL*/
    FILE* pOutfile = NULL;           /*Set pOutfile to be NULL*/

    /*Copy files from arguement array to local variables*/
    inputFile = strdup(argv[1]);
    outputFile = strdup(argv[1]);

    /*Check arguement to make sure that we have the right number. If not,print error message*/
    if(argc != 2)
        {
        printf("Error, You do not supply the correct arguments\n");
        exit(1);
        }

    /*Check to make sure that inputFile or outputFile is not NULL. If it is. print error message*/
    if((inputFile == NULL) || (outputFile == NULL))
        {
        printf("Error, Memory allocation error in strdup\n");
        exit(1);
        }

    /*Open input file*/
    pInfile = fopen("person.txt","r");

    /*Check that the open succeeded, If not,print error message*/
    if(pInfile == NULL)
        {
        printf("Error, can not open file\n");
        }

    else
        {
        /*change to be stored in buffer*/
        while(fgets(inputBuffer,128,pInfile) != NULL)
            {
            sscanf(inputBuffer, "%s %s %s %s %s %s %s",person[i].passportID, person[i].firstName,
            person[i].lastName, person[i].expireDate, person[i].entryDate, person[i].exitDate,
            person[i].visaType);

            i++;
            }

        line = i;
        }

    fclose(pInfile);

    printf("Which item do you need to modify?\n");
    printf("press 1 - Modify Firstname\n");
    printf("press 2 - Modify Lastname\n");
    printf("press 3 - Modify Passport expiration date\n");
    printf("press 4 - Modify Date of last entry into Thailand\n");
    printf("press 5 - Modify Date of last exit from Thailand\n");
    printf("Which item do you need to modify: ");

    fgets(inputBuffer,128,stdin);
    sscanf(inputBuffer,"%d",&modify);

    while((modify <= 0) || (modify >= 6))
        {
            printf("Sorry, You have to press 1,2,3,4, or 5. Try again");
            printf("Which item do you need to modify: ");
            fgets(inputBuffer,128,stdin);
            sscanf(inputBuffer,"%d",&modify);
        }

    switch(modify)
        {
        case 1:     /*name*/
            strcpy(person[index].firstName, newValue);
            break;
        case 2:     /*lastname*/
            strcpy(person[index].lastName, newValue);
            break;
        case 3:     /*date 1*/
            strcpy(person[index].expireDate, newValue);
            break;
        case 4:     /*date 2*/
            strcpy(person[index].entryDate, newValue);
            break;
        case 5:     /*date 3*/
            strcpy(person[index].exitDate, newValue);
            break;
        case 6:     /*TypePas*/
            strcpy(person[index].visaType, newValue);
            break;
        }


    pOutfile = fopen("person.txt","w");

    /*Check to make sure that inputFile or outputFile is not NULL. If it is. print error message*/
    if((inputFile == NULL) || (outputFile == NULL))
        {
        printf("Error, Memory allocation error in strdup\n");
        exit(1);
        }

        for(j = 0; j < line; j++)
            {
            fprintf(pOutfile,"%s %s %s %s %s %s %s\n",person[j].passportID, person[j].firstName,
            person[j].lastName, person[j].expireDate, person[j].entryDate, person[j].exitDate,
            person[j].visaType);
            }
    fclose(pOutfile);

}

This is modifyImmigration.h

void Edit(int argc, char* argv[], char *newValue, int index, int modify, DATA_T person[100]);

and this is structure.h

typedef struct
{
    char passportID[16];        /* Passport ID of the user */
    char firstName[30];         /* First name of the user */
    char lastName[30];          /* Last name of the user */
    char expireDate[10];        /* Expiration date of the passport */
    char entryDate[10];         /* Date of last entry into Thailand */
    char exitDate[10];          /* Date of last exit from Thailand */
    char visaType[30];          /* Type of visa */
} DATA_T;

Why is there an error: undefine reference to '_Edit'

Thank you for your help

[Sebastiani]

You need to compile modifyImmigration.c into an object file, and then pass this along to the linker when you compile or link your main program.