strip16bytes.c

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[])
{
    if(argc < 2)
    {
        printf("Error: you need to give me a file name to work on.\n");
        return (1);
    }
    else
    {
        FILE *infile;
        if ((infile = fopen(argv[1], "rb")))
        /* 'b' is necessary because windows is dumb and noncompliant as usual */
        {
            /* do this if the file exists: */
            fseek(infile, 0L, SEEK_END);
            long size = ftell(infile);
            fseek(infile, 0L, SEEK_SET);
            printf("size: %ld\n",size);
            if(size < 16)
            {
                printf("The file size is less than 16 bytes; this shouldn't ever happen.\nExiting.\n");
                fclose(infile);
                return (1);
            }
            /* set an output file name, in the format of origfilename_stripped.swf */
            int output;
            char outputFileName[strlen(argv[1]) + 10]; /* '_stripped' is 9 bytes, null terminator makes ten */
            size_t j=0; /* size_t is annoying. */
            int k=0; /* because size_t is unsigned I have to keep track with both signed and unsigned numbers. */
            while ( j < ( strlen(argv[1]) - 4 )) /* '.swf' is 4 chars */
            {
                outputFileName[k]=argv[1][k];
                ++j;
                ++k;
            }
            /* then append '_stripped.swf' */
            /* yes, there are better ways. but I am too lazy to try to remember them. */
            outputFileName[k]='_';
            outputFileName[k+1]='s';
            outputFileName[k+2]='t';
            outputFileName[k+3]='r';
            outputFileName[k+4]='i';
            outputFileName[k+5]='p';
            outputFileName[k+6]='p';
            outputFileName[k+7]='e';
            outputFileName[k+8]='d';
            outputFileName[k+9]='.';
            outputFileName[k+10]='s';
            outputFileName[k+11]='w';
            outputFileName[k+12]='f';
            outputFileName[k+13]='\0';
            printf("output file name: %s\n",outputFileName);

            FILE *outfile;
            outfile = fopen(outputFileName,"w+b");
            /* 'b' is necessary because windows is dumb and noncompliant as usual */
            long i=0;
            while(i < (size - (long)16))
            {
                /* start copying bytes from infile to outfile. */
                /* stops 16 bytes from the end of the input file. */
                /* this has the effect of truncating 16 bytes. */
                fputc(fgetc(infile),outfile);
                ++i;
            }
            printf("%ld\n",i);

            fclose(outfile);
            fclose(infile);
            return (0);
        }
    }
    return (0);
}