

UPPER CASE TO LOWER CASE
#include<stdio.h>
#include<stdlib.h>
int main()
{
FILE *fp1,*fp2;
char ch;
fp1=fopen("E:/test2.txt","r");
if(fp1==NULL)
{
printf("Sourse file not open properly ");
exit(0);
}
fp2=fopen("e:/test1.txt","w");
if(fp2==NULL)
{
printf("Tergect file not open properly ");
exit(0);
}
while((ch=fgetc(fp1))!=EOF)
{
if(ch>64&&ch<91)
ch=ch+32;
fputc(ch,fp2);
}
fclose(fp1);
fclose(fp2);
printf("Upper case to lower case convertion sucessfully ");
return 1;
}

LOWER CASE TO UPPER CASE
#include<stdio.h>
#include<stdlib.h>
int main()
{
FILE *fp1,*fp2;
char ch;
fp1=fopen("E:/test1.txt","r");
if(fp1==NULL)
{
printf("Sourse file not open properly ");
exit(0);
}
fp2=fopen("e:/test2.txt","w");
if(fp2==NULL)
{
printf("Tergect file not open properly ");
exit(0);
}
while((ch=fgetc(fp1))!=EOF)
{
if(ch>=97)
ch=ch-32;
fputc(ch,fp2);
}
fclose(fp1);
fclose(fp2);
printf("Lower case to upper case convertion sucessfully ");
return 1;
}
