Member Avatar for hikaru1239

Hi, I was practicing for our hands on exams tomorrow when I encountered a problem in my code. Here is a part of my code:

void interactive(){ //if argument is 0, program will enter the interactive mode.

    int choice;
    int year, month, day;
    char div[40];
    char tags[WORD_COUNT];
    char entry[WORD_COUNT];

        printf("\t\t....................................................\n");
        printf("\t\t  What do you wish to do?\n");
        printf("\n\n\t\t[1]\tAdd new entry\n\t\t[2]\tEdit entry\n\t\t[3]\tList Entry\n\t\t[4]\tQuit\n");
        scanf("%d", &choice);
        printf("\nYour choice is: %d\n\n", choice);
        inFile = fopen("journal.txt", "a");

        if(choice == 1){

            printf("Enter your entry's date [yy,mm,dd format]: ");
            scanf("%d, %d, %d", &year, &month, &day);
            fprintf(inFile, "------------------------------------------------------------------------------\n\n%s", div);
            fprintf(inFile, "Date: %d, %d, %d\n", year, month, day);


            printf("[Tags: Press ^Z to proceed] Enter your post's keywords: ");

            while(fgets(tags, WORD_COUNT, stdin)){

            len = strlen(tags);
            tags[len-1] = '\0';

            }

            fprintf(inFile, "\nTags: %s", tags);

            printf("\n[Press ^Z to post] Your entry:\n\n");

            while(fgets(entry, WORD_COUNT, stdin)){

            len2 = strlen(entry);
            entry[len2-1] = '\0';

            }

            fprintf(inFile, "\n\n>START OF ENTRY\n\n\n %s \n\n\n>END OF ENTRY\n\n\n", entry);
            fclose(inFile);


            }

        if(choice == 4){

            printf("Thank you for using ............................. \n\n");
            printf("Program will now terminate\n");
            exit(0);


            }

        if (choice > 4){

            printf("Your choice is not in the menu. Program will now terminate\n\n");

            }


    }

The problem is in this part:

while(fgets(entry, WORD_COUNT, stdin)){

            len2 = strlen(entry);
            entry[len2-1] = '\0';

            }

This is the part that retrieves the user input which will be copied to a text file. However, this only allows to retrieve a single line of text instead of retrieving everything that was entered by the user.

For example, the user enters:
---------------------------------------------------
Let's see... So far, nothing good happened to me. I look back and all I see were a bunch mistakes that I have committed. All I see were things I knew I shouldn't have done but...

<enter>

Am I still in control of my life? Sometimes, I think don't have the authority anymore. Why did I end up with something that only takes half of my interest (BSMMA)? And why did I end up here when I was...
---------------------------------------------------

The program will only retrieve the part after the user presses enter for the next paragraph.

How do I fix this code so that it will not only retrieve the user input per line but everything that the user entered for the entry tag?

Thanks for the help.

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  • Latest Post Latest Post by Aia

Dani AI

Generated

Your code is overwriting the same fixed buffer each time you call a line reader, so only the last read remains. correctly pointed to stdin buffering and the risk of overruns, and suggested concatenation. Two quick fixes: stop mixing scanf/fgets (flush the trailing newline after scanf), and accumulate input either by appending each read to a growing buffer or by writing each line straight to the file as you read it.

Flush the leftover newline after any scanf that leaves an end‑of‑line in the stream:

int c;
while ((c = getchar()) != '\n' && c != EOF)
    ;

A robust, compact approach is to read lines with getline() and build a dynamically growing string with realloc(), or write each line directly to the journal file as it arrives. Example pattern (POSIX getline + realloc): read each line, stop on a sentinel (like a single dot line) or EOF, realloc a larger buffer to hold the new chunk, memcpy the chunk in, and NUL‑terminate. Remember to check return values and handle allocation failures; free buffers on error.

Notes and pitfalls:

  • Do not unconditionally do buf[len-1] = '\0' — check len > 0 first. Trimming without checking can clobber memory for empty reads.
  • Initialize any variables you print (for example div is used before being set).
  • For portability: EOF is Ctrl+D on Unix, Ctrl+Z on Windows; using a sentinel line (e.g., a single . or END on its own line) is clearer to users than relying on Ctrl+Z.
  • Writing each line straight to the file as you read it avoids large memory use for long posts.

See the POSIX getline() man page for details: getline manual and the realloc reference for safe resizing: realloc reference.

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Member Avatar for BestJewSinceJC

You would keep a pointer to the String that you wish to store it in and concatenate your 'new' user entry onto whatever the String's current contents are. OR you could make the function 'return' whatever the user entered as a String, and concatenate that entry with whats stored in the current String.


I haven't coded in C recently, but those are the only two ways you can do this. The pseudocode for the second way would look like this:

int main(){
String allTextEntered;
String currentEntry = interactive();
allTextEntered + currentEntry; //PSEUDOCODE - WONT WORK AS TYPED. CONCEPT WORKS.
}

String interactive(){
//code to get text from the user

return userEntry;
}

Member Avatar for Aia

The standard input (stdin) is buffered. That's why you can write and nothing happens until you give the signal to go ahead and read. That occurs when you press ENTER/RETURN.

fgets() can only read up to n-1 of whatever size of buffer you have set apart for it. In this case WORD_COUNT. That portion of read needs to be store in some memory or next time when while() goes through, variable entry will be over written. After fgets() can not read anything else, entry will hold the last portion of input available.
If you would know before hand how much is there in the input you could create an array big enough to hold everything; by copying and concatenating each read, using strcpy() and strcat().
The risk is that more input could be entered than this array memory can hold, creating a buffer overrun.

The other alternative is learning about dynamic memory. Which it is somehow out of the reach of a quick example.

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