Question

I am try to write a buffer so I can remove a lot of null “00” characters in a file. The characters are useless and are completely random. They are wreaking havoc on the searcher in the program. The code below compiles but just seems to hang when a file is passed to it. Any suggestions will be helpful.

void ReadFile(char *name)
{
    FILE *dbg;
    char *buffer;
    unsigned long fileLen;

    //Open file
    dbg = fopen(dbg, "w+");
    if (!dbg)
    {
        fprintf(stderr, "Unable to open file %s", name);
        return;
    }

    //Get file length
    fseek(dbg, 0, SEEK_END);
    fileLen = ftell(dbg);
    fseek(dbg, 0, SEEK_SET);

    //Allocate memory
    buffer = (char *)malloc(fileLen+1);
    if (!buffer)
    {
        fprintf(stderr, "Memory error!");
        fclose(dbg);
        return;
    }

    //Read file contents into buffer
    fread(buffer, fileLen, 1, dbg);
    for(i = fileLen-1; i >= 0 && buffer[i] == 0; i--);  
    i++;
    if (i > 0)
    {
        fwrite(buffer, 1, i, dbg);
    }
    fclose(dbg);

    //Do what ever with buffer

    free(buffer);
}

Answer 1

Change

dbg = fopen(dbg, "w+");

to

dbg = fopen(name, "w+");

Also, if you want to read the file, change it then write it, you shouldn’t open it with "w+". You should first open the file with "r", read from it, do whatever change you want, then fclose it, then again open it but this time with "w" so that you write over it. After you have opened it in "w"rite mode, you can write the modified buffer back into the file.