为什么一次删除和重命名一次不起作用？

Question

I want to delete a line from a file I use as a "database". I do this with copying everything expect that line to a new file, then deleting the old one and renaming the new one. I know this is not the best solution probably, but that's not the point now. The problem is, that I do this with 2 files, and it doesn't work with the first one, but works perfectly with the second one. I have no idea what casusing the problem. (The problem is that the first remove and rename does nothing, and returs with -1 which is the error code.)

Here is the code:

#define defaultBuilds "build.txt"
#define defaultAnswers "answers.txt"

FILE* fop = fopen(defaultAnswers, "r"); //forrasfile
    FILE* fdp = fopen("temp_a.txt", "w"); //ideiglenes cel file

    //bejegyzesek masolasa
    char buff[buffSize];
    int ind;
    for(int i = 0; i < lines; i++)
    {
        fgets(buff, buffSize, fop);
        if(i != sor) //kiveve a torlendo bejegyzest
            fprintf(fdp, "%s", buff);
        else if(i == sor)
        {
            //tolendo bejegyzeshez tartozo index meghatarozasa
            int end, start;
            for(end = 0; buff[end] != 0; end++);
            for(start = end; buff[start] != ' '; start--);
            char temp[50];
            for(int j = ++start, k = 0; j < end; j++, k++)
                temp[k] = buff[j];
            sscanf(temp, "%d", &ind);
        }
    }

    fclose(fop);
    fclose(fdp);

    remove(defaultAnswers); //regi torlese
    rename("temp_a.txt", defaultAnswers); //uj atnevezese


    fop = fopen(defaultBuilds, "r");
    fdp = fopen("temp_b.txt", "w");

    //szamitogepek masolasa
    int temp;
    for(int i = 0; i < lines; i++)
    {
        fscanf(fop, "%d\n", &temp);
        if(temp != ind) //torlendo kihagyasa
            fprintf(fdp, "%d\n", temp);
        for(int j = 0; j < defaultAmountOfParts; j++)
        {
            fgets(buff, buffSize, fop);
            if(temp != ind)
            {
                if(j == 0)
                    fprintf(fdp, "\t");
                fprintf(fdp, "%s", buff);
            }
        }
    }
    fclose(fop);
    fclose(fdp);

    remove(defaultBuilds);  //torles
    rename("temp_b.txt", defaultBuilds); //atnevezes

Oh and here is the folder structure:

I can probably solve the problem in an ugly way but i would be really happy if i could use this method, it is much more simple.

EDIT: I found that remove() has the error of: Permission denied , which i don't know why is happening. I checked, fclose closes the file succesfully.

Answer 1

I want to delete a line from a file I use as a "database". I do this with copying everything expect that line to a new file, then deleting the old one and renaming the new one. I know this is not the best solution probably, but that's not the point now. The problem is, that I do this with 2 files, and it doesn't work with the first one, but works perfectly with the second one. I have no idea what casusing the problem. (The problem is that the first remove and rename does nothing, and returs with -1 which is the error code.)

Here is the code:

#define defaultBuilds "build.txt"
#define defaultAnswers "answers.txt"

FILE* fop = fopen(defaultAnswers, "r"); //forrasfile
    FILE* fdp = fopen("temp_a.txt", "w"); //ideiglenes cel file

    //bejegyzesek masolasa
    char buff[buffSize];
    int ind;
    for(int i = 0; i < lines; i++)
    {
        fgets(buff, buffSize, fop);
        if(i != sor) //kiveve a torlendo bejegyzest
            fprintf(fdp, "%s", buff);
        else if(i == sor)
        {
            //tolendo bejegyzeshez tartozo index meghatarozasa
            int end, start;
            for(end = 0; buff[end] != 0; end++);
            for(start = end; buff[start] != ' '; start--);
            char temp[50];
            for(int j = ++start, k = 0; j < end; j++, k++)
                temp[k] = buff[j];
            sscanf(temp, "%d", &ind);
        }
    }

    fclose(fop);
    fclose(fdp);

    remove(defaultAnswers); //regi torlese
    rename("temp_a.txt", defaultAnswers); //uj atnevezese


    fop = fopen(defaultBuilds, "r");
    fdp = fopen("temp_b.txt", "w");

    //szamitogepek masolasa
    int temp;
    for(int i = 0; i < lines; i++)
    {
        fscanf(fop, "%d\n", &temp);
        if(temp != ind) //torlendo kihagyasa
            fprintf(fdp, "%d\n", temp);
        for(int j = 0; j < defaultAmountOfParts; j++)
        {
            fgets(buff, buffSize, fop);
            if(temp != ind)
            {
                if(j == 0)
                    fprintf(fdp, "\t");
                fprintf(fdp, "%s", buff);
            }
        }
    }
    fclose(fop);
    fclose(fdp);

    remove(defaultBuilds);  //torles
    rename("temp_b.txt", defaultBuilds); //atnevezes

Oh and here is the folder structure:

I can probably solve the problem in an ugly way but i would be really happy if i could use this method, it is much more simple.

EDIT: I found that remove() has the error of: Permission denied , which i don't know why is happening. I checked, fclose closes the file succesfully.