Code:
#include <stdio.h>
FILE *f_in, *f_out;
int var, k, status;
char output, chrr;
main()
{
printf("Enter a value from 0 to 9.\n");
scanf("%d", &k);
if (k>=0 && k<=9)
{
f_in = fopen("message.txt", "r");
f_out = fopen("encrypted.txt", "w");
//status = fscanf (f_in, "%c", &var);
//chrr = (int) input
while (var != EOF)
{
fscanf(f_in, "%d", &var);
fscanf(f_in, "%c", &chrr);
if ((chrr>=48) && (chrr<=57))
{
if (chrr==57)
{
if(k==0)
{
output=57;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=47+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==56)
{
if(k<=1)
{
output=56+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=46+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==55)
{
if(k<=2)
{
output=55+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=45+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==54)
{
if(k<=3){
output=54+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=44+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==53)
{
if(k<=4){
output=53+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=43+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==52)
{
if(k<=5){
output=52+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=42+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==51)
{
if(k<=6){
output=51+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=41+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==50)
{
if(k<=7){
output=50+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=40+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==49)
{
if(k<=8){
output=49+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=39+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr==48)
{
output=48+k;
fprintf( f_out, "%c", output);
printf("%c", output);
}
}
else if ((chrr>='a') && (chrr<='z'))
{
if (chrr=='z')
{
if(k==0){
output=122;
fprintf( f_out, "%c", output);
printf("%c", output);
}
else {
output=96+k;
fprintf( f_out,"%c", output);
printf("%c",output);
}
}
if (chrr=='y')
{
if(k==0 || k==1)
{
output=121+k;
fprintf( f_out, "%c", output);
}
else {
output=95+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='x')
{
if(k>=0 && k<=2)
{
output=120+k;
fprintf( f_out, "%c", output);
}
else {
output=94+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='w')
{
if(k<=3)
{
output=119+k;
fprintf( f_out, "%c", output);
}
else {
output=93+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='v')
{
if(k<=4)
{
output=118+k;
fprintf( f_out, "%c", output);
}
else {
output=92+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='u')
{
if(k<=5)
{
output=117+k;
fprintf( f_out, "%c", output);
}
else {
output=91+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='t')
{
if(k<=6)
{
output=116+k;
fprintf( f_out, "%c", output);
}
else {
output=90+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='s')
{
if(k<=7)
{
output=115+k;
fprintf( f_out, "%c", output);
}
else {
output=89+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='r')
{
if(k<=8)
{
output=114+k;
fprintf( f_out, "%c", output);
}
else {
output=88+k;
fprintf( f_out, "%c", output);
}
}
else {
while((chrr>='a') && (chrr<='q'))
{
output=(chrr+k);
fprintf( f_out, "%c", output);
printf("%c", output);
break;
}
}
}
else if (chrr>='A' && chrr<='Z')
{
if (chrr=='Z')
{
if(k==0){
output=90;
fprintf( f_out, "%c", output);
}
else {
output=64+k;
fprintf( f_out,"%c", output);
}
}
if (chrr=='Y')
{
if(k==0 || k==1)
{
output=89+k;
fprintf( f_out, "%c", output);
}
else {
output=63+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='X')
{
if(k>=0 && k<=2)
{
output=88+k;
fprintf( f_out, "%c", output);
}
else {
output=62+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='W')
{
if(k<=3)
{
output=87+k;
fprintf( f_out, "%c", output);
}
else {
output=61+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='V')
{
if(k<=4)
{
output=86+k;
fprintf( f_out, "%c", output);
}
else {
output=60+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='U')
{
if(k<=5)
{
output=85+k;
fprintf( f_out, "%c", output);
}
else {
output=59+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='T')
{
if(k<=6)
{
output=84+k;
fprintf( f_out, "%c", output);
}
else {
output=58+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='S')
{
if(k<=7)
{
output=83+k;
fprintf( f_out, "%c", output);
}
else {
output=57+k;
fprintf( f_out, "%c", output);
}
}
if (chrr=='R')
{
if(k<=8)
{
output=82+k;
fprintf( f_out, "%c", output);
}
else {
output=56+k;
fprintf( f_out, "%c", output);
}
}
else if (chrr>='A' && chrr<='Q')
{
output=(chrr+k);
fprintf( f_out, "%c", output);
printf("%c", output);
}
}
else
{
output=chrr;
fprintf( f_out, "%c", output);
printf("%c", output);
break;
}
}
fclose(f_in);
fclose(f_out);
}
/* else {
printf("The integer is not from 0 to 9");
break;
}
*/
}
Now for some reason it's reading the scanf value but it doesn't write anything. It appears to go into the if/else loops but nothing happens.