Chap12[C]j Sort data in file according to date

There are 100 records present in a file with the following structure:
struct date
{
int d, m, y ;
} ;
struct employee
{ int empcode[6] ;
char empname[20] ;
struct date join_date ;
float salary ;
} ;
Write a program to read these records, arrange them in ascending order of join_date and write them in to a target file.

#include "stdio.h"
struct date
{
int d,m,y;
};
struct employee
{
int empcode;
char empname[20];
struct date da;
float salary;
};

void main()
{
int choice;
char another,another2;
FILE *fs;
struct employee e;
fs=fopen("c:\\ctxt\\join.txt","a+");
while(1)
{
clrscr();
printf("1) Input new employee data");
printf("\n2) Sort employee data");
printf("\n3) Exit");
printf("\n\nKey in your choice(1,2 or 3)\n");
scanf("%d",&choice);

switch(choice)
{
case 1:
while(1)
{
clrscr();
printf("\nKey in employee's code\n");
scanf("%d",&e.empcode);
printf("\nKey in employee's name\n");
scanf("%s",e.empname);
printf("\nKey in year that employee joined\n");
scanf("%d",&e.da.y);
printf("\nKey in month that employee joined\n");
scanf("%d",&e.da.m);
printf("\nKey in day that employee joined\n");
scanf("%d",&e.da.d);
printf("\nKey in salary of employee\n");
scanf("%f",&e.salary);
fprintf(fs,"%d %s %d %d %d %f\n",e.empcode,e.empname,e.da.y,e.da.m,e.da.d,e.salary);
printf("\nDo you want to key in another data?(y/n)\n");
fflush(stdin);
another=getche();
if(another!='y')
break;
}
break;

case 2:
funcsort(fs);
break;

case 3:
fclose(fs);
exit();
}
}
}

funcsort(FILE *fs)
{
int i,j,flag=0,count=0;
struct employee temp1,temp2;
struct employee e1[1000];
char ch;
FILE *fp;
fp=fopen("c:\\ctxt\\join2.txt","w");
rewind(fs);
for(i=0;i<1000;i++)
{
if(flag==0)
{
ch=fscanf(fs,"%d%s%d%d%d%f",&e1[i].empcode,e1[i].empname,&e1[i].da.y,&e1[i].da.m,&e1[i].da.d,&e1[i].salary);
count++;
if(ch==EOF)
flag=1;
}
if(flag==1)
{
e1[i].empname[0]='\0';
}
}
for(i=0;e1[i].empname[0]!=0;i++)
{
for(j=i+1;j {
if(e1[i].da.y>e1[j].da.y)
{
temp1=e1[i];
temp2=e1[j];
e1[i]=temp2;
e1[j]=temp1;
}
else if((e1[i].da.y==e1[j].da.y)&&(e1[i].da.m==e1[j].da.m))
{
if(e1[i].da.d>e1[j].da.d)
{
temp1=e1[i];
temp2=e1[j];
e1[i]=temp2;
e1[j]=temp1;
}
}
else if(e1[i].da.y==e1[j].da.y)
{
if(e1[i].da.m>e1[j].da.m)
{
temp1=e1[i];
temp2=e1[j];
e1[i]=temp2;
e1[j]=temp1;
}
}

}
}

for(i=0;e1[i].empname[0]!=0;i++)
{
fprintf(fp,"%d %s %d %d %d %f\n",e1[i].empcode,e1[i].empname,e1[i].da.y,e1[i].da.m,e1[i].da.d,e1[i].salary);
}
fclose(fp);
fclose(fs);
remove("c:\\ctxt\\join.txt");
rename("c:\\ctxt\\join2.txt","c:\\ctxt\\join.txt");
fs=fopen("c:\\ctxt\\join.txt","a+");
}

Chap12[C]i Updating customer transactions with sorting feature

In the file ‘CUSTOMER.DAT’ there are 100 records with the following structure:
struct customer
{
int accno ;
char name[30] ;
float balance ;
} ;

In another file ‘TRANSACTIONS.DAT’ there are several records with the following structure:
struct trans
{
int accno ;
char trans_type ;
float amount ;
} ;
The parameter trans_type contains D/W indicating deposit or withdrawal of amount. Write a program to update ‘CUSTOMER.DAT’ file, i.e. if the trans_type is ‘D’ then update the balance of ‘CUSTOMER.DAT’ by adding amount to balance for the corresponding accno. Similarly, if trans_type is ‘W’ then subtract the amount from balance. However, while subtracting the amount make sure that the amount should not get overdrawn, i.e. at least 100 Rs. Should remain in the account.

Create a folder "ctxt" in C drive. In the "ctxt" folder create two text files with name cust.txt and trans.txt.
when option 4 is executed trans.txt get deleted while new transactions can be created with option 5 in program.

#include "stdio.h"
struct customer
{
int accno;
char name[30];
float balance;
};

struct trans
{
int accno;
char trans_type[1];
float amount;
};

void main()
{
char another,name1[30];
FILE *fs,*ft,*ftemp;
struct customer c;
struct trans t;
int choice,no,f2,no2,counter;
long pos1,pos2,pos3;
fs=fopen("c:\\ctxt\\cust.txt","r+");

if(fs==NULL)
{
puts("Cannot open file");
exit();
}

while(1)
{
clrscr();
printf("1)List Customer Data");
printf("\n2)Add Customer Data");
printf("\n3)Remove Customer Data");
printf("\n4)Update Customer Data from transactions");
printf("\n5)Perform transactions");
printf("\n6)Exit\n");
scanf("%d",&choice);
rewind(fs);

switch(choice)
{
case 1:

another='y';
clrscr();
while(fscanf(fs,"%d%s%f",&c.accno,c.name,&c.balance)!=EOF)
printf("\nAccount no: %3d Name: %-20s Balance: %.1f",c.accno,c.name,c.balance);
while(1)
{
printf("\n\nHit enter to escape");
fflush(stdin);
another=getche();
if(another!='y')
break;
}
break;

case 2:

clrscr();
another='y';
no=1;
funcsort(fs);
while(1)
{

f2=0;

for(no=1;fscanf(fs,"%d%s%f",&c.accno,c.name,&c.balance)!=EOF;no++)
{
if(f2==0)
{
if(c.accno!=no)
{
no2=no;
f2=1;
}

}

}
printf("\nKey in Customer name\n");
scanf("%s",c.name);
printf("\nKey in balance\n");
scanf("%f",&c.balance);
if(f2==1)
{
fprintf(fs,"%d %s %f\n",no2,c.name,c.balance);
}
else
{
fprintf(fs,"%d %s %f\n",no,c.name,c.balance);
no++;
}
funcsort(fs);
printf("\nAdd another customer Data(y/n)?\n");
fflush(stdin);
another=getche();
if(another!='y')
break;
}
break;

case 3:

another='y';
clrscr();

while(1)
{
ftemp=fopen("c:\\ctxt\\cust2.txt","w");
printf("\nKey in name to delete\n");
scanf("%s",name1);
while(fscanf(fs,"%d%s%f",&c.accno,c.name,&c.balance)!=EOF)
{
if(strcmp(c.name,name1)!=0)
fprintf(ftemp,"%d %s %f\n",c.accno,c.name,c.balance);
}
fclose(fs);
fclose(ftemp);
remove("c:\\ctxt\\cust.txt");
rename("c:\\ctxt\\cust2.txt","c:\\ctxt\\cust.txt");
printf("\nDelete another data?(y/n)\n");
fflush(stdin);
fs=fopen("c:\\ctxt\\cust.txt","r+");
another=getche();
if(another!='y')
break;
}
break;

case 4:

clrscr();
ft=fopen("c:\\ctxt\\trans.txt","r");
if(ft==NULL)
{
puts("No active transactions");
exit();
}
while(fscanf(ft,"%d%s%f",&t.accno,t.trans_type,&t.amount)!=EOF)
{
counter=0;
pos1=0;
rewind(fs);
while(fscanf(fs,"%d%s%f",&c.accno,c.name,&c.balance)!=EOF)
{
counter++;
pos2=pos1;
pos1=ftell(fs);
pos3=pos1-pos2;
if(t.accno==c.accno)
{
if(t.trans_type[0]=='w')
{
c.balance-=t.amount;
if(c.balance<100)
{
c.balance+=t.amount;
printf("\nTransaction for account no: %d not processed due to insufficient funds");
}
}
if(t.trans_type[0]=='d')
{
c.balance+=t.amount;

}
if(counter==1)
fseek(fs,-(pos3),SEEK_CUR);
if(counter>1)
fseek(fs,-(pos3-2),SEEK_CUR);
fprintf(fs,"%d %s %f\n",c.accno,c.name,c.balance);
counter=1;
}

}
}
fclose(ft);
remove("c:\\ctxt\\trans.txt");
break;

case 5:

clrscr();
another='y';
ft=fopen("c:\\ctxt\\trans.txt","a+");
if(ft==NULL)
{
puts("Cannot open file");
break;
}
while(1)
{
printf("\nKey in acc no.\n");
scanf("%d",&t.accno);
printf("\nWithdraw (w) or Deposit (d)\n");
scanf("%s",t.trans_type);
printf("\nKey in amount\n");
scanf("%f",&t.amount);
fprintf(ft,"%-3d %s %-6.2f\n",t.accno,t.trans_type,t.amount);
printf("\nDo you want to key another transaction(y/n)?\n");
fflush(stdin);
another=getche();
if(another!='y')
break;
}
fclose(ft);
break;

case 6:

fclose(fs);
exit();

}
}
fclose(fs);
}

funcsort(FILE *fp)
{
char ch;
int flag=0,i,j,count;
struct customer a[1000],temp1,temp2;
FILE *ftemp;
rewind(fp);
ftemp=fopen("c:\\ctxt\\cust2.txt","w");
for(i=0,count=0;i<1000;i++)
{
if(flag==0)
{
ch=fscanf(fp,"%d%s%f",&a[i].accno,a[i].name,&a[i].balance);
count++;
if(ch==EOF)
{
flag=1;
}
}
if(flag==1)
{
a[i].name[0]=0;
}
}

for(i=0;a[i].name[0]!=0;i++)
{
for(j=i+1;j<(count-1);j++)
{
if(a[i].accno>a[j].accno)
{
temp1=a[i];
temp2=a[j];
a[i]=temp2;
a[j]=temp1;
}
}
}

for(i=0;a[i].name[0]!=0;i++)
{
fprintf(ftemp,"%d %s %f\n",a[i].accno,a[i].name,a[i].balance);
}
fclose(fp);
fclose(ftemp);
remove("c:\\ctxt\\cust.txt");
rename("c:\\ctxt\\cust2.txt","c:\\ctxt\\cust.txt");
fp=fopen("c:\\ctxt\\cust.txt","r+");
}

Chap12[C]h Encrypting/Decrypting file

Write a program to encrypt/decrypt a file using:
An offset cipher: In an offset cipher each character from the source file is offset with a fixed value and then written to the target file. For example, if character read from the source file is ‘A’, then convert this into a new character by offsetting ‘A’ by a fixed value, say 128, and then writing the new character to the target file.

Program to encrypt file

#include "stdio.h"
void main()
{
FILE *fp,*ft;
char ch;

fp=fopen("c:\\ctxt\\cipher.txt","r");
if(fp==NULL)
{
puts("Cannot open file");
exit();
}
ft=fopen("c:\\ctxt\\cipher2.txt","w");
if(ft==NULL)
{
puts("Cannot open file");
exit();
}

while(1)
{
ch=fgetc(fp);
if(ch==EOF)
break;
ch+=128;
fputc(ch,ft);
};
fclose(fp);
fclose(ft);
remove("c:\\ctxt\\cipher.txt");
rename("c:\\ctxt\\cipher2.txt","c:\\ctxt\\cipher.txt");
}

Program to decrypt the same file


#include "stdio.h"
void main()
{
FILE *fp,*ft;
char ch;
fp=fopen("c:\\ctxt\\cipher.txt","r");
if(fp==NULL)
{
puts("Cannot open file");
exit();
}
ft=fopen("c:\\ctxt\\cipher2.txt","w");
if(ft==NULL)
{
puts("Cannot open file");
exit();
}
while(1)
{
ch=fgetc(fp);
if(ch==EOF)
break;
ch-=128;
fputc(ch,ft);
};
fclose(fp);
fclose(ft);
remove("c:\\ctxt\\cipher.txt");
rename("c:\\ctxt\\cipher2.txt","c:\\ctxt\\cipher.txt");
}

Chap12[C]d Sorting to alphabetical order in a file

Suppose a file contains student’s records with each record containing name and age of a student. Write a program to read these records and display them in sorted order by name.

Program to input students name
#include "stdio.h"

void main()
{
char j='y';
FILE *fp;

struct record
{
char name[20];
int age;
};
struct record a;

fp=fopen("c:\\ctxt\\record.txt","a");
if(fp==NULL)
{
puts("Cannot open file");
exit();
}
while(j=='y')
{
printf("\nKey in the name of the student\n");
scanf("%s",a.name);
printf("\nKey in the age of the student\n");
scanf("%d",&a.age);
fprintf(fp,"%s %d\n",a.name,a.age);
printf("\nAdd another record?(Y/N)");
fflush(stdin);
j=getche();
}
fclose(fp);
}

Program to sort students name


#include "stdio.h"
struct record
{
char name[10];
int age;
};
void main()
{
FILE *fp,*ft;

int i,f=1;

struct record a[5000];

clrscr();


fp=fopen("c:\\ctxt\\record.txt","r");
if(fp==NULL)
{
puts("Cannot open file");
exit();
}
for(i=0;i<5000;i++)
{
if(f==1)
{
if((fscanf(fp,"%s%d",a[i].name,&a[i].age)==EOF))
f=0;
}
if(f==0)
a[i].name[0]='\0';

}

funcsort(a,4);

for(i=0;a[i].name[0]!='\0';i++)
printf("\nName is %s. Age is %d",a[i].name,a[i].age);
printf("\nFile sorted according to alphabetical order");

ft=fopen("c:\\ctxt\\record2.txt","w");
for(i=0;a[i].name[0]!=0;i++)
fprintf(ft,"%s %d\n",a[i].name,a[i].age);
fclose(fp);
fclose(ft);
remove("c:\\ctxt\\record.txt");
rename("c:\\ctxt\\record2.txt","c:\\ctxt\\record.txt");

}
/* Function "funcsort()" is in picture below type it in for it to work */

Chap12[C]g Reading text on console with pages

Write a program to display the contents of a text file on the screen. Make following provisions: Display the contents inside a box drawn with opposite corner co-ordinates being ( 0, 1 ) and ( 79, 23 ). Display the name of the file whose contents are being displayed, and the page numbers in the zeroth row. The moment one screenful of file has been displayed, flash a message ‘Press any key...’ in 24th row. When a key is hit, the next page’s contents should be displayed, and so on till the end of file.

Create a folder called "ctxt" in C drive and create a text file called page.txt in the ctxt folder.
Input lots of words into the page.txt file then run this program.

#include "stdio.h"
#include "dos.h"

void main()
{
void creategrid();
FILE *fp;
char ch,k;
int page=1,i,j,pgno,flag=0,count;


fp=fopen("c:\\ctxt\\page.txt","r");
while(1)
{
count=0;
clrscr();
creategrid();
for(i=3;i<=21&&flag!=1;i++)
{

for(j=4;j<=77&&flag!=1;j++)
{
ch=fgetc(fp);
if(ch==EOF)
{
flag=1;
break;
}
gotoxy(j,i);
printf("%c",ch);
count++;
}
}
gotoxy(38,24);
printf("Page %d",page);
if(page>1)
{
gotoxy(3,24);
printf("Key %c to go to page %d",17,page-1);
}
if(flag!=1)
{
gotoxy(58,24);
printf("Key %c to go to page %d",16,page+1);
}
if(flag==1)
{
gotoxy(66,24);
printf("Key %c to quit",16);
}
while(1)
{
pgno=getkey();
if(flag==1&&pgno==77)
break;
if(page==1&&pgno==75)
continue;

if(pgno==77&&flag!=1)
{
page+=1;
clrscr();
creategrid();
break;
}

if(pgno==75&&page!=1)
{
page-=1;
clrscr();
fseek(fp,-(1413+count),SEEK_CUR);
creategrid();
flag=0;
break;
}
}
if(flag==1&&pgno==77)
break;



}
fclose(fp);
}

getkey()
{
union REGS i,o;
while(!kbhit())
;
i.h.ah=0;
int86(22,&i,&o);
return(o.h.ah);
}

void creategrid()
{
int i;
gotoxy(2,1);
printf("%c",218);
gotoxy(79,1);
printf("%c",191);
gotoxy(2,23);
printf("%c",192);
gotoxy(79,23);
printf("%c",217);

for(i=3;i<=78;i++)
{
gotoxy(i,1);
printf("%c",196);
gotoxy(i,23);
printf("%c",196);
}

for(i=2;i<=22;i++)
{
gotoxy(2,i);
printf("%c",179);
gotoxy(79,i);
printf("%c",179);
}
}

Chap12[C]f Merge alternate lines from two files

Write a program that merges lines alternately from two files and writes the results to new file. If one file has less number of lines than the other, the remaining lines from the larger file should be simply copied into the target file.

#include "stdio.h"
void main()
{
FILE *fp,*ft,*fs;
char ch;
int f1=1,f2=1,counter=1;

fp=fopen("c:\\ctxt\\first.txt","r");
ft=fopen("c:\\ctxt\\second.txt","r");
fs=fopen("c:\\ctxt\\combine.txt","w");

while(1)
{
if(counter==1||f2==0)
{
ch=fgetc(fp);
if(ch==EOF)
f1=0;
if(ch=='\n'||ch==46)
counter=2;
if(f1!=0)
fputc(ch,fs);
}

if(counter==2||f1==0)
{
ch=fgetc(ft);
if(ch==EOF)
f2=0;

if(ch=='\n'||ch==46)
counter=1;
if(f2!=0)
fputc(ch,fs);

if(f1==0&&f2==0)
break;
}
}

fclose(fp);
fclose(ft);
fclose(fs);
}

Chap12[C]e Lowercase to uppercase in file

Write a program to copy one file to another. While doing so replace all lowercase characters to their equivalent uppercase characters.

#include "stdio.h"

void main()
{
FILE *fp,*ft;
char ch;

fp=fopen("c:\\ctxt\\txt1.txt","r");
ft=fopen("c:\\ctxt\\txt2.txt","w");

if(fp==NULL)
{
puts("Cannot open file");
exit();
}

if(ft==NULL)
{
puts("Cannot open file");
exit();
}

while(1)
{
ch=fgetc(fp);
if(ch==EOF)
break;
if(ch>=97&&ch<=122)
ch-=32;
fputc(ch,ft);
}

fclose(fp);
fclose(ft);
}