So I have this homework wherein I have to translate a text from a file into EuroEnglish but I'm stuck at the part where I have to create a linked list of characters. What seems to be missing in my code? I'm still trying to understand how linked lists works so I apologize if the code below isn't written well.
I also would like to ask for a few tips on how I can implement a function that checks each individual characters and apply the rules of EuroEnglish.
#include <stdio.h>
#include <stdlib.h>
void file_contents();
void converted_file();
FILE *fp;
char c;
int i = 0;
struct L;
struct L
{
char letter;
struct L *next;
};
int main(int argc, char *argv[])
{
if (argc != 2)
printf("USAGE: %s <filename>", argv[0]);
else
{
fp = fopen(argv[1], "r");
if (fp == 0)
{
printf("Could not open file.\n");
exit(1);
}
else
{
file_contents();
converted_file();
fclose(fp);
}
}
}
void file_contents()
{
printf("\nYour file contains:\n\n");
while ((c = getc(fp)) != EOF)
printf("%c", c);
printf("\n");
}
void converted_file()
{
struct L *first, *tail, *head;
printf("\nText converted in EuroEnglish:\n");
while ((c = getc(fp)) != EOF)
{
first = (struct L *) malloc(sizeof(struct L));
first->letter = c;
first->next = NULL;
if (tail == NULL)
head = tail = first;
else
{
tail->next = first;
tail = first;
}
}
while (first != NULL)
{
printf("%c", first->letter);
first = first->next;
}
}
Best practices recommend to avoid global. Here you have used fd
as a global variable and opened it in main. Ok until there. Then you read it until end of file in file_contents
. It is still fine, but the file pointer is now at end of file...
When you try to read in converted_file
, getc
immediately returns an end of file... But as fd
is global you did not notice it. This can be fixed by rewinding the file with fseek(fd, 0, SEEK_SET);
You have another rewind problem inside converted_file
: after all characters have been read, first
points to the last character, but you try to display the file content starting from there. You should insert a first = head;
here, or replace the while
lop with:
for(first=head; first!=NULL; first=first->next) {
printf("%c", first->letter);
}
I have not tried to run it so other problems could remain...
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