Thursday 28 July 2016

A database in C that uses error trapping in the create new record and delete record routines to make it user friendly.


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

typedef struct {
char name[42];
char street[42];
char district[42];
char town[42];
char county[42];
char country[42];
char postcode[42];
char telno[42];
char email[42];
}addr_list;
addr_list address[MAX];
int counter;
void init_list(void), enter(void);
void delete(void), list(void);
void load(void), save(void), copyfile(void), sort(void);
void loadbackup(void), outputthree(void);
void outputtwo(void), search(void);
void readLine(char buffer[]);
void swap(int u, int v);
void readinteger(char intbuffer[]);
int main(void)
{
int choice;
char s[80];
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.  Save to a back up file\n");
printf("9.  Load from a backup file or copy\n"); 
printf("10. Copy master file\n");
printf("11. Output to a text file for printing or import into wp\n");
printf("12. Quit\n");
do {
printf("\nEnter your choice: ");
readLine(s);
choice=atoi(s);
}while(choice < 0 && choice > 11);
switch(choice) {
case 1: enter();
break;
case 2: delete();
break;
case 3: list();
break;
case 4: save();
break;
case 5: load();
break;
case 6: sort();
break;
case 7: search();
break;
case 8: outputtwo();
break;
case 9: loadbackup();
break;
case 10: copyfile();
break;
case 11: outputthree();
break;
case 12: exit(0);
}
}
return 0;
}

void init_list(void)
{
register int t;

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

void enter(void)
{
char s[40];
int i;
for(i=1; i<MAX; i++)
if(!*address[i].name)
break;
if(i==MAX)
{
printf("Subscriber array full\n");
return;
}
printf("Enter information on new customer\n");
do
{
printf("Enter name: ");
readLine(address[i].name);
if(strlen(address[i].name)>40)
{
printf("String length is %i\n",strlen(address[i].name));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].name)>40);
do
{
printf("Enter street: ");
readLine(address[i].street);
if(strlen(address[i].street)>40)
{
printf("String length is %i\n",strlen(address[i].street));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].street)>40);
do
{
printf("Enter district / parish: ");
readLine(address[i].district);
if(strlen(address[i].district)>40)
{
printf("String length is %i\n",strlen(address[i].district));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].district)>40);
do
{
printf("Enter town / city: ");
readLine(address[i].town);
if(strlen(address[i].town)>40)
{
printf("String length is %i\n",strlen(address[i].town));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].town)>40);
do
{
printf("Enter county: ");
readLine(address[i].county);
if(strlen(address[i].county)>40)
{
printf("String length is %i\n",strlen(address[i].county));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].county)>40);
do
{
printf("Enter country: ");
readLine(address[i].country);
if(strlen(address[i].country)>40)
{
printf("String length is %i\n",strlen(address[i].country));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].country)>40);
do
{
printf("Enter postcode: ");
readLine(address[i].postcode);
if(strlen(address[i].postcode)>40)
{
printf("String length is %i\n",strlen(address[i].postcode));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].postcode)>40);
do
{
printf("Enter telephone number: ");
readLine(address[i].telno);
if(strlen(address[i].telno)>40)
{
printf("String length is %i\n",strlen(address[i].telno));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].telno)>40);
do
{
printf("Enter email address: ");
readLine(address[i].email);
if(strlen(address[i].email)>40)
{
printf("String length is %i\n",strlen(address[i].email));
printf("Please restrict to forty characters.\n");
}
}while(strlen(address[i].email)>40);
counter=counter+1;
}



void delete(void)
{
char number[20];
int t;
int u;
int count;
int flag=0;
printf("enter a record number #: ");
readLine(number);
for(count=0;number[count]!='\0';count++)
{
if(!isdigit(number[count]))
{
printf("Not a valid number\n.");
flag = 1;
break;
}
}
if(flag == 0)
{
if(number[0] == '\0')
printf("No number entered.\n");
else
{
t=atoi(number);
if(t<1 || t >counter)
printf("Record number not within range.\n");

if(t>=1 && t <=counter)
{
for(u=t; u<=counter; u++){
address[u] = address[u+1];
}
address[counter].name[0] = '\0';
address[counter].street[0] = '\0';
address[counter].district[0] = '\0';
address[counter].town[0] = '\0';
address[counter].county[0] = '\0';
address[counter].country[0] = '\0';
address[counter].postcode[0] = '\0';
address[counter].telno[0] = '\0';
address[counter].email[0] = '\0';
counter = counter -1;
printf("Record deleted.\n");
}
}
}
}

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", address[t].name);
printf("%s\n", address[t].street);
printf("%s\n", address[t].district);
printf("%s\n", address[t].town);
printf("%s\n", address[t].county);
printf("%s\n", address[t].country);
printf("%s\n", address[t].postcode);
printf("%s\n", address[t].telno);
printf("%s\n", address[t].email);
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(address[u].name, address[v].name) >0){
swap(u, v);
}
}
}

void swap(int u, int v)
{
addr_list temp;
temp = address[u];
address[u] = address[v];
address[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(*address[i].name)
if(fwrite(&address[i],
sizeof(address[i]), 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(&address[i],
sizeof(address[i]), 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(&address[i],
sizeof(address[i]), 1, fp)!=1) {
if(feof(fp)) break;
printf("File read error.\n");
}
counter=counter +1;
}
fclose(fp);
}


void outputthree(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(address[t].name[0]) {
count = count +1;
fprintf(stream,"%i\n",count); 
fprintf(stream,"%s\n", address[t].name);
fprintf(stream,"%s\n", address[t].street);
fprintf(stream,"%s\n", address[t].district);
fprintf(stream,"%s\n", address[t].town);
fprintf(stream,"%s\n", address[t].county);
fprintf(stream,"%s\n", address[t].country);
fprintf(stream,"%s\n", address[t].postcode);
fprintf(stream,"%s\n", address[t].telno);
fprintf(stream,"%s\n", address[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(*address[i].name)
if(fwrite(&address[i],
sizeof(address[i]), 1, fp)!=1)
printf("File write error.\n");

fclose(fp);
}

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

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

void copyfile(void)
{
FILE *in, *out;
int c;
char filename[30];
if ((in = fopen ("maillist", "r")) ==NULL){
printf("Cant open %s file for reading.\n","cdlist");
}
printf("Enter a file name.for the target file\n");
scanf("%s",filename);
printf("\n");
if ((out = fopen(filename, "w")) ==NULL){
printf("Cant open %s for writing.\n", "cdlistbackup");
}

while ((c = getc (in)) !=EOF)
putc (c, out);
fclose (in);
fclose(out);
printf("File has been copied.\n");
}

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


void readinteger(char intbuffer[])
{
int number;
int j=0;
do
{
number=getchar();
intbuffer[j]=number;
++j;
}
while(number !='\n');
intbuffer[j-1]='\0';
}

No comments:

Post a Comment