#include "stdio.h"
#include "stdlib.h"

int main(int argc, char* argv[])
{    
    /* pointers to file for writing and file containg the header */
    FILE * fpWrite;
    FILE * fpReviewHeader;
    /* size of file and header */
    long lSizeOfHeader = -1;
    long lSizeOfFile = -1;
    /* buffer to keep the header to be appended */
    char * buffer;

    /* at least one file must be passed */
    if( argc < 2 )
    {
        printf("\nUsage: acrh <filename>\n");
    }

    /* open file have the header in read and binary mode
       you make like to take this also from command line also.
       This file starts with a new line character used
       in case the file where header will be appended does
       not have new line character in the end */
    fpReviewHeader=fopen("c:\\temp\\review.txt", "rb");

    /* get the file size */
    fseek (fpReviewHeader , 0 , SEEK_END);
    lSizeOfHeader = ftell (fpReviewHeader);
    rewind (fpReviewHeader);
    
    /* allocate memory to contain the whole header file.*/
    buffer = (char*) malloc (lSizeOfHeader);
    
    /* read the file into the buffer. */
    fread (buffer,1,lSizeOfHeader,fpReviewHeader);    
    
    /* get all the file names passed on the command line*/
    for(int i=1;i<argc;++i)
    {
        /* open the each file in append and binary mode */
        fpWrite=fopen(argv[i], "ab+");
        /* here we get the size of the file and check if the
           second last character is new line character    */
        fseek (fpWrite , 0 , SEEK_END);
        lSizeOfFile = ftell (fpWrite);
        rewind (fpWrite);
        fseek (fpWrite , lSizeOfFile-2 , SEEK_SET);
        int aChar = fgetc(fpWrite);
        fseek (fpWrite , 0 , SEEK_END);
        /* if no newline is there we append the original buffer with new line    */
        if( aChar != 13 )
        {
            fwrite(buffer,1,lSizeOfHeader,fpWrite);            
        }
        /* remove the newline character from buffer */
        else
        {
            /* write the block header to file */
            fwrite(buffer+2,1,lSizeOfHeader-2,fpWrite);        
        }
        printf("\nUpdated: %s",argv[i]);
        /* this flushes the data from cache to file */
        fflush(fpWrite);
        /* close this file */
        fclose(fpWrite);
    }
    /* close the header file */
    fclose(fpReviewHeader);
    /* free the header buffer */
    free(buffer);

    return 0;
}