A C database that puts a date stamp on each record.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<time.h>
#define MAX 10000

struct addr {
char name[40];
char street[40];
char district[40];
char town[40];
char county[40];
char country[40];
char postcode[40];
char telno[40];
char email[40];
int year;
int month;
int day;
}addr_list[MAX];

struct addr temp;
int counter;
void init_list(void), enter(void);
void delete(void), list(void);
void load(void), save(void), sort(void);
void txtoutput(void);
void search(void), searchbydate(void);
void readLine(char buffer[]);
void swap(int u, int v);
int main(void)
{
int choice;
char s[3];
counter = 0;
init_list();
for(;;){
printf("\n");
printf("1.  Create a record\n");
printf("2.  Delete a record\n");
printf("3.  List the file\n");
printf("4.  Save the file\n");
printf("5.  Load the file\n");
printf("6.  Sort the file\n");
printf("7.  Search by name\n");
printf("8.  Search by date\n");
printf("9.  Output to a text file for printing or import into wp\n");
printf("10.  Quit\n");
do{
printf("\nEnter your choice: ");
readLine(s);
choice=atoi(s);
if(choice== 1) enter();
if(choice==2) delete();
if(choice==3) list();
if(choice==4) save();
if(choice==5) load();
if(choice==6) sort();
if(choice==7) search();
if(choice==8) searchbydate();
if(choice== 9) txtoutput();
if(choice== 10) exit(0);
}while(choice < 1 && choice >10);
}
return 0;
}

void init_list(void)
{
register int t;

for(t=0; t<MAX; ++t) addr_list[t].name[0] ='\0';
}

void enter(void)
{
char s[40];
int i;
for(i=1; i<MAX; i++)
if(!*addr_list[i].name)
break;
if(i==MAX)
{
printf("Subscriber array full\n");
return;
}
printf("Enter information on new customer\n");

printf("Enter name: ");
readLine(addr_list[i].name);

printf("Enter street: ");
readLine(addr_list[i].street);

printf("Enter district / parish: ");
readLine(addr_list[i].district);

printf("Enter town / city: ");
readLine(addr_list[i].town);

printf("Enter county: ");
readLine(addr_list[i].county);

printf("Enter country: ");
readLine(addr_list[i].country);

printf("Enter postcode: ");
readLine(addr_list[i].postcode);

printf("Enter telephone number: ");
readLine(addr_list[i].telno);

printf("Enter email address: ");
readLine(addr_list[i].email);
time_t lt;
lt = time(NULL);

struct tm tm = *localtime(&lt);

addr_list[i].year = tm.tm_year + 1900;
addr_list[i].month = tm.tm_mon + 1;
addr_list[i].day = tm.tm_mday;
printf("%i %i %i\n", addr_list[i].day, addr_list[i].month,
addr_list[i].year);

counter=counter+1;
}



void delete(void)
{
int t;
int u;
printf("enter a record number #: ");
scanf("%i", &t);
getchar();
for(u=t; u<=counter; u++){
addr_list[u] = addr_list[u+1];
}
addr_list[counter].name[0] = '\0';
addr_list[counter].street[0] = '\0';
addr_list[counter].district[0] = '\0';
addr_list[counter].town[0] = '\0';
addr_list[counter].county[0] = '\0';
addr_list[counter].country[0] = '\0';
addr_list[counter].postcode[0] = '\0';
addr_list[counter].telno[0] = '\0';
addr_list[counter].email[0] = '\0';
addr_list[counter].year = '\0';
addr_list[counter].month = '\0';
addr_list[counter].day = '\0';
counter = counter -1;
}

void list(void)
{
register int t;
int count;
count=0;
for(t=1; t<=counter; t++) {
count = count +1;
printf("Record number: %i\n",count);
printf("%s\n", addr_list[t].name);
printf("%s\n", addr_list[t].street);
printf("%s\n", addr_list[t].district);
printf("%s\n", addr_list[t].town);
printf("%s\n", addr_list[t].county);
printf("%s\n", addr_list[t].country);
printf("%s\n", addr_list[t].postcode);
printf("%s\n", addr_list[t].telno);
printf("%s\n", addr_list[t].email);
printf("%i %i %i\n",addr_list[t].day, addr_list[t].month,
addr_list[t].year);
printf("\n");
}
}

void sort(void)
{
register int u;
register int v;
for(u=1; u<counter; u++)
for (v=u+1; v<=counter; v++){
if( strcmp(addr_list[u].name, addr_list[v].name) >0){
swap(u, v);
}
}
}
void swap(int u, int v)
{
temp = addr_list[u];
addr_list[u]=addr_list[v];
addr_list[v]=temp;
}

void save(void)
{
FILE *fp;
register int i;

if((fp=fopen("maillist", "wb"))==NULL) {
printf("Cannot open file.\n");
return;
}

for(i=1; i<MAX; i++)
if(*addr_list[i].name)
if(fwrite(&addr_list[i],
sizeof(struct addr), 1, fp)!=1)
printf("File write error.\n");

fclose(fp);
}




void load(void)
{
FILE *fp;
register int i;

if((fp=fopen("maillist", "rb"))==NULL) {
printf("Cannot open file,\n");
return;
}

init_list();
for(i=1;  i<MAX; i++){
if(fread(&addr_list[i],
sizeof(struct addr), 1, fp)!=1) {
if(feof(fp)) break;
printf("File read error.\n");
}
counter=counter +1;
}
fclose(fp);
}


void txtoutput(void)
{
int t;
int count;
FILE *stream;
char filename[30];
count = 0;
printf("Enter a file name.\n");
scanf("%s",filename);
printf("\n");
stream = fopen(filename, "w+");
for(t=1; t<MAX; t++) {
if(addr_list[t].name[0]) {
count = count +1;
fprintf(stream,"%i\n",count);
fprintf(stream,"%s\n", addr_list[t].name);
fprintf(stream,"%s\n", addr_list[t].street);
fprintf(stream,"%s\n", addr_list[t].district);
fprintf(stream,"%s\n", addr_list[t].town);
fprintf(stream,"%s\n", addr_list[t].county);
fprintf(stream,"%s\n", addr_list[t].country);
fprintf(stream,"%s\n", addr_list[t].postcode);
fprintf(stream,"%s\n", addr_list[t].telno);
fprintf(stream,"%s\n", addr_list[t].email);
fprintf(stream,"%i %i %i\n", addr_list[t].day,
addr_list[t].month, addr_list[t].year);
fprintf(stream,"\n");
}
}
fclose(stream);
return;
}


void search(void)
{
int i;
int count;
count=0;
char s[40];
printf("\nEnter a name.\n");
readLine(s);
for(i=1;i<MAX;i++)
{
if(addr_list[i].name[0]) {
count = count +1;
}

if (strcmp(s, addr_list[i].name)==0)
{
printf("\nRecord number: %i\n", count);
printf("\nName: %s\n",addr_list[i].name);
printf("\nStreet: %s\n",addr_list[i].street);
printf("\nDistrict: %s\n",addr_list[i].district);
printf("\nTown: %s\n",addr_list[i].town);
printf("\nCounty: %s\n",addr_list[i].county);
printf("\nCountry: %s\n",addr_list[i].country);
printf("\nPostcode:%s\n",addr_list[i].postcode);
printf("\nTelephone number: %s\n",addr_list[i].telno);
printf("\nEmail address: %s\n",addr_list[i].email);
printf("\nDate: %i %i %i\n", addr_list[i].day,
addr_list[i].month, addr_list[i].year);
printf("\n");
}
}
}

void searchbydate(void)
{
int i;
int count;
count=0;
int d, m, y;
printf("\nEnter a day of the month for example 10\n");
scanf("%i",&d);
printf("\nEnter a month of the year for example 2\n");
scanf("%i",&m);
printf("\nEnter a year for example 2017\n");
scanf("%i",&y);
getchar();
for(i=1;i<MAX;i++)
{
if(addr_list[i].name[0]) {
count = count +1;
}

if(addr_list[i].day== d && addr_list[i].month==m
&& addr_list[i].year==y)
{
printf("\nRecord number: %i\n", count);
printf("\nName: %s\n",addr_list[i].name);
printf("\nStreet: %s\n",addr_list[i].street);
printf("\nDistrict: %s\n",addr_list[i].district);
printf("\nTown: %s\n",addr_list[i].town);
printf("\nCounty: %s\n",addr_list[i].county);
printf("\nCountry: %s\n",addr_list[i].country);
printf("\nPostcode: %s\n",addr_list[i].postcode);
printf("\nTelephone number: %s\n",addr_list[i].telno);
printf("\nEmail address: %s\n",addr_list[i].email);
printf("\nDate record created: %i %i %i\n",addr_list[i].day,
addr_list[i].month, addr_list[i].year);
printf("\n");
}
}
}   
   

void readLine(char buffer[])
{
char character;
int i=0;
do
{
character=getchar();
buffer[i]=character;
++i;
}
while(character !='\n');
buffer[i-1]='\0';
}

A C database that uses the C qsort routine and a binary chop search.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define MAX 10000
typedef struct{
char name[40];
char street[40];
char district[40];
char town[40];
char county[40];
char country[40];
char postcode[40];
char telno[40];
char email[40];
}addr;
addr addr_list[MAX];
int cmp (const void * a, const void * b)
{

 const addr *addrA = a;
 const addr *addrB = b;

if(strcmp(addrA->name, addrB->name)>0)
return 1;

if(strcmp(addrA->name, addrB->name)<0)
return -1;

if(strcmp(addrA->name, addrB->name)==0)
return 0;
}
int num_addresses;
int counter;
void init_list(void), enter(void);
void delete(void), list(void);
void load(void), save(void);
void txtoutput(void);
void search(void);
void readLine(char buffer[]);

int main(void)
{
int choice;
char s[3];
counter = 0;
init_list();
for(;;){
printf("\n");
printf("1.  Create a record\n");
printf("2.  Delete a record\n");
printf("3.  List the file\n");
printf("4.  Save the file\n");
printf("5.  Load the file\n");
printf("6.  Sort the file\n");
printf("7.  Search\n");
printf("8.  Output to a text file for printing or import into wp\n");
printf("9.  Quit\n");
do{
printf("\nEnter your choice: ");
readLine(s);
choice=atoi(s);
if(choice== 1) enter();
if(choice==2) delete();
if(choice==3) list();
if(choice==4) save();
if(choice==5) load();
if(choice==6) qsort(addr_list, counter+1, sizeof(addr), &cmp);
/*I assume it is counter+1 for qsort instead of counter because array of records
starts at addr_list[1] instead of addr_list[0]*/
if(choice==7) search();
if(choice== 8) txtoutput();
if(choice== 9) exit(0);
}while(choice < 1 && choice >9);
}
return 0;
}

void init_list(void)
{
register int t;

for(t=0; t<MAX; ++t) addr_list[t].name[0] ='\0';
}

void enter(void)
{
char s[40];
int i;
for(i=1; i<MAX; i++)
if(!*addr_list[i].name)
break;
if(i==MAX)
{
printf("Subscriber array full\n");
return;
}
printf("Enter information on new customer\n");

printf("Enter name: ");
readLine(addr_list[i].name);

printf("Enter street: ");
readLine(addr_list[i].street);

printf("Enter district / parish: ");
readLine(addr_list[i].district);

printf("Enter town / city: ");
readLine(addr_list[i].town);

printf("Enter county: ");
readLine(addr_list[i].county);

printf("Enter country: ");
readLine(addr_list[i].country);

printf("Enter postcode: ");
readLine(addr_list[i].postcode);

printf("Enter telephone number: ");
readLine(addr_list[i].telno);

printf("Enter email address: ");
readLine(addr_list[i].email);
counter=counter+1;
}



void delete(void)
{
int t;
int u;
printf("enter a record number #: ");
scanf("%i", &t);
getchar();
for(u=t; u<=counter; u++){
addr_list[u] = addr_list[u+1];
}
addr_list[counter].name[0] = '\0';
addr_list[counter].street[0] = '\0';
addr_list[counter].district[0] = '\0';
addr_list[counter].town[0] = '\0';
addr_list[counter].county[0] = '\0';
addr_list[counter].country[0] = '\0';
addr_list[counter].postcode[0] = '\0';
addr_list[counter].telno[0] = '\0';
addr_list[counter].email[0] = '\0';
counter = counter -1;
}

void list(void)
{
register int t;
int count;
count=0;
for(t=1; t<=counter; t++) {
count = count +1;
printf("Record number: %i\n",count);
printf("%s\n", addr_list[t].name);
printf("%s\n", addr_list[t].street);
printf("%s\n", addr_list[t].district);
printf("%s\n", addr_list[t].town);
printf("%s\n", addr_list[t].county);
printf("%s\n", addr_list[t].country);
printf("%s\n", addr_list[t].postcode);
printf("%s\n", addr_list[t].telno);
printf("%s\n", addr_list[t].email);
printf("\n");
}
}

void save(void)
{
FILE *fp;
register int i;

if((fp=fopen("maillist", "wb"))==NULL) {
printf("Cannot open file.\n");
return;
}

for(i=1; i<MAX; i++)
if(*addr_list[i].name)
if(fwrite(&addr_list[i],
sizeof(addr), 1, fp)!=1)
printf("File write error.\n");

fclose(fp);
}

void loadbackup(void)
{
FILE *fp;
register int i;
char filename[30];
printf("Enter a file name.\n");
scanf("%s",filename);
printf("\n");

if((fp=fopen(filename, "rb"))==NULL) {
printf("Cannot open file,\n");
return;
}

init_list();
for(i=1;  i<MAX; i++){
if(fread(&addr_list[i],
sizeof(addr), 1, fp)!=1) {
if(feof(fp)) break;
printf("File read error.\n");
}
counter=counter+1;
}
fclose(fp);
}



void load(void)
{
FILE *fp;
register int i;

if((fp=fopen("maillist", "rb"))==NULL) {
printf("Cannot open file,\n");
return;
}

init_list();
for(i=1;  i<MAX; i++){
if(fread(&addr_list[i],
sizeof(addr), 1, fp)!=1) {
if(feof(fp)) break;
printf("File read error.\n");
}
counter=counter +1;
}
fclose(fp);
}


void txtoutput(void)
{
int t;
int count;
FILE *stream;
char filename[30];
count = 0;
printf("Enter a file name.\n");
scanf("%s",filename);
printf("\n");
stream = fopen(filename, "w+");
for(t=1; t<MAX; t++) {
if(addr_list[t].name[0]) {
count = count +1;
fprintf(stream,"%i\n",count);
fprintf(stream,"%s\n", addr_list[t].name);
fprintf(stream,"%s\n", addr_list[t].street);
fprintf(stream,"%s\n", addr_list[t].district);
fprintf(stream,"%s\n", addr_list[t].town);
fprintf(stream,"%s\n", addr_list[t].county);
fprintf(stream,"%s\n", addr_list[t].country);
fprintf(stream,"%s\n", addr_list[t].postcode);
fprintf(stream,"%s\n", addr_list[t].telno);
fprintf(stream,"%s\n", addr_list[t].email);
fprintf(stream,"\n");
}
}
fclose(stream);
return;
}



void outputtwo(void)
{
FILE *fp;
register int i;
char filename[30];
printf("Enter a file name.\n");
scanf("%s",filename);
printf("\n");
if((fp=fopen(filename, "wb"))==NULL) {
printf("Cannot open file.\n");
return;
}

for(i=1; i<MAX; i++)
if(*addr_list[i].name)
if(fwrite(&addr_list[i],
sizeof(addr), 1, fp)!=1)
printf("File write error.\n");

fclose(fp);
}

void search(void)
{

int low, mid, top, found,count,countdown;
char s[40];
printf("\nEnter a name.\n");
readLine(s);
low = 1;
top = counter;
do
{
found = 0;
mid = (low + top)/2;


if (strcmp(s, addr_list[mid].name)==0)
{
printf("\nRecord number: %i\n", mid);
printf("\nName: %s\n",addr_list[mid].name);
printf("\nStreet: %s\n",addr_list[mid].street);
printf("\nDistrict: %s\n",addr_list[mid].district);
printf("\nTown: %s\n",addr_list[mid].town);
printf("\nCounty: %s\n",addr_list[mid].county);
printf("\nCountry: %s\n",addr_list[mid].country);
printf("\nPostcode:%s\n",addr_list[mid].postcode);
printf("\nTelephone number: %s\n",addr_list[mid].telno);
printf("\nEmail address: %s\n",addr_list[mid].email);
printf("\n");
/*break;*/
count = mid;
countdown = mid;

do
{
countdown=countdown-1;
if(strcmp(s, addr_list[countdown].name)==0)
{
printf("\nRecord number: %i\n", countdown);
printf("\nName: %s\n",addr_list[countdown].name);
printf("\nStreet: %s\n",addr_list[countdown].street);
printf("\nDistrict: %s\n",addr_list[countdown].district);
printf("\nTown: %s\n",addr_list[countdown].town);
printf("\nCounty: %s\n",addr_list[countdown].county);
printf("\nCountry: %s\n",addr_list[countdown].country);
printf("\nPostcode:%s\n",addr_list[countdown].postcode);
printf("\nTelephone number: %s\n",addr_list[countdown].telno);
printf("\nEmail address: %s\n",addr_list[countdown].email);
printf("\n");   
}
}while(strcmp(s,addr_list[countdown].name)==0);

do{
count=count +1;
if(strcmp(s, addr_list[count].name)==0)
{
printf("\nRecord number: %i\n", count);
printf("\nName: %s\n",addr_list[count].name);
printf("\nStreet: %s\n",addr_list[count].street);
printf("\nDistrict: %s\n",addr_list[count].district);
printf("\nTown: %s\n",addr_list[count].town);
printf("\nCounty: %s\n",addr_list[count].county);
printf("\nCountry: %s\n",addr_list[count].country);
printf("\nPostcode:%s\n",addr_list[count].postcode);
printf("\nTelephone number: %s\n",addr_list[count].telno);
printf("\nEmail address: %s\n",addr_list[count].email);
printf("\n");
}
}while(strcmp(s,addr_list[count].name)==0);

return;
}
else
if(strcmp(s, addr_list[mid].name)<0)
top = mid -1;
else
if(strcmp(s, addr_list[mid].name)>0)
low = mid + 1;
}while(low<=top);
}
void readLine(char buffer[])
{
char character;
int i=0;
do
{
character=getchar();
buffer[i]=character;
++i;
}
while(character !='\n');
buffer[i-1]='\0';
}