Why rename() and remove() functions don't work?

Question

If I use this code alone (with a main function) it works.

But when I include this function in my project, it give two files :

annuaire_client.txt and annuaire1.txt

The code used is provided below:

void delete_client(){
    FILE *annuaire_client,*annuaire1;
    printf("\t\t\t\t\t\t\t\tNum de compte a supprimee: ");

    int delete_line;
    scanf("%d",&delete_line);

    char ch;
    int  line = 1;

    //ouvrir le fichier original
    annuaire_client = fopen("annuaire_client.txt", "r");
    ch = getc(annuaire_client);

    //retour au debut
    rewind(annuaire_client);
    //ouvrir nouveau fichier
    annuaire1 = fopen("annuaire1.txt", "w");

    while (ch != EOF)
    {
        if (ch == '\n')
        {
            line++;
        }
        //sautez la line a supprimer
        if (line != delete_line)
        {
            //copier les lines vers annuaire1.txt
            fprintf(annuaire1,"%c",ch);
        }

        ch = getc(annuaire_client);
    }

    fclose(annuaire1);
    fclose(annuaire_client);
    remove("annuaire_client.txt");
    rename("annuaire1.txt","annuaire_client.txt");
}

Answer 1

You should check the returned value of remove and rename:

    if (remove("annuaire_client.txt") != 0) {
        /* handle error */
    }
    if (rename("annuaire1.txt","annuaire_client.txt") == -1) {
        /* handle error */
    }

One of many possibilities is that you keep descriptor opened by main function while calling remove. Make sure you pair all fopen with fclose or even if you unlink / remove paths your process will still keep (deleted) descriptors open which may cause fatal errors if you reach the limit of descriptors allocated for it ( fopen will fail - this has happened to me today, so it is not purely artificial situation). Remember also, it is undefined behavior to call fclose on invalid pointer, ie not a FILE* , on NULL in particular.

Answer 2

You can try check the result code for your functions. For instance, for rename function you can use some code like:

   #include <errno.h>

(...)

   int ret;

   ret = rename("annuaire1.txt", "annuaire_client.txt");

   if(ret == 0) 
   {
      printf("File renamed successfully");
   }
   else 
   {
      printf("Error: unable to rename the file");
      fprintf(stderr, "System error (%d): %s\n", errno, strerror(errno);
   }

Answer 3

Try writing the full path of the file in the remove function and in the new name in the rename function. For example:

remove("C:\\Documents\\annuaire_client.txt");
rename("anuuaire1.txt","C:\\Documents\\annuaire_client.txt");

Remember to use the \\\\ instead of \\