i have to create a program in c

Question

in which i have to take a file as a input and then seprate the comments from the file and save to new file
my code is here
#include<stdio.h>
#include<stdlib.h>
void check_comment (char) ;
void block_comment () ;
void single_comment () ;

FILE *fp,*fp2,*fp3;
void main()
{

char filename[20];
char str;
printf("\n enter the file name with path :");
scanf("%s",filename);
fp = fopen(filename,"r+");
if(fp==NULL)
{
printf("\n can't open the file ");
exit(0);

}

printf("\n Enter the filename to open for writing \n");
scanf("%s", filename);

fp2 = fopen(filename, "w+");
if (fp2 == NULL)
{
printf("Cannot open file %s \n", filename);
exit(0);
}

str = fgetc(fp);
while (str != EOF)
{
check_comment(str);

str = fgetc(fp);
printf("%c",str);

}

printf("\nContents copied to %s", filename);

printf("\n Enter the filename to open for writing \n");
scanf("%s", filename);

fp3=fopen(filename,"w+");
fclose(fp);
fclose(fp2);
fclose(fp3);
return 0;

}
void check_comment(char str)
{
char d;

if( str == '/') {
if((d=fgetc(fp))=='*')
block_comment();
else if( d == '/') {
single_comment();

}
else
{
fputc(str,fp2);

}
}
else
fputc(str,fp2);
}

void single_comment()
{
char d,e;

while((d=fgetc(fp))!=EOF) {

fputs(d,fp3);
if(d=='\n')

return 0;
}

}
void block_comment()
{

char d,e;

while((d=fgetc(fp))!=EOF) {
fputc(d,fp3);

if(d=='*') {
e=fgetc(fp);

if(e=='/')
return 0;
}
}

}

Answer 1

That is a cool program to separate single line vs. block comments. I think why it doesn't work in Code Playground is because of a security measure that SoloLearn has wisely implemented so we as users cannot modify files in our own nor other users' folders using a program.