Copying Only Part of a File to a New One in C - c

Question

I have a practice question in C that asks me to create a function that only copies part of a file to another one. The restrictions are that lines with greater than maxlen characters are not copied to the new file, and the newline character does not count, so it should not be copied. Part of my function says that if a file does not exist, it should explicitly say so, and I am getting those error messages when I run that code; however, I can see that the files are created are inside my folder. Whenever I open the file I'm trying to read after running the code, I get this:
./Debug/main.c.o ./Debug/dot.c.o ./Debug/dataBase.c.o ./Debug/intPrompt.c.o ./Debug/numWords.c.o ./Debug/LinkedList.c.o
Below is my code :
void shortLines(char* f1, char* f2, int maxlen) {
FILE* fp = fopen(f1, "r");
FILE* fp2 = fopen(f2, "w");
if (fp == NULL) {
perror("File does not exist");
}
if (fp2 == NULL) {
perror("File does not exist");
}
char singleLine[maxlen];
char check;
size_t len;
do {
fgets(singleLine, maxlen, fp);
len = strlen(singleLine);
if (singleLine[len-1] == '\n') {
singleLine[len-1] = '\0';
}
fprintf(fp2, "%s", singleLine);
} while ((check=getc(fp) != EOF));
}
int main(int argc, char **argv) {
shortLines("Andrew.txt", "Andrew2.txt", 25);
return 0;
}

Answer 1

I just made new files called Andrew.txt and Andrew2.txt and these ones seem to be working for some strange reason. Regardless, there were a few problems in the code. First of all, after fgets is called, I needed to make sure to flush out the remaining characters in the line. I do this with a while loop and fgetc. If I reach an EOF, then I continue, and then fgets also returns an EOF, thus breaking the outer loop.
void shortLines(char* f1, char* f2, int maxlen) {
FILE* fp = fopen(f1, "r");
FILE* fp2 = fopen(f2, "w");
if (fp == NULL) {
perror(f1);
}
if (fp2 == NULL) {
perror(f2);
}
char line[maxlen+1];
size_t len;
char c;
while (fgets(line, maxlen+1, fp) != NULL) {
len = strlen(line);
if (len == maxlen) {
while ((c=fgetc(fp)) != '\n') {
if (feof(fp)) {
break;
}
}
continue;
}
if (line[len-1] == '\n') {
line[len-1] = '\0';
}
fprintf(fp2, "%s\n", line);
}
}