#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include "dbg.h"


int main(int argc, char *argv[])
{
    int fd;
    int rc;
    long lrc;
    char *out;
    char buffer[1024];
    fpos_t pos;
    FILE *instream;
    FILE *outstream;

    check(argc == 2, "You must provide a filename.");

    fd = open(argv[1], O_RDWR | O_CREAT);
    check(fd != -1, "Unable to open \"%s\" for reading and writing.", argv[1]);

    rc = fchmod(fd, 0644);
    check(rc != -1, "Failed to chmod \"%s\"", argv[1]);

    outstream = fdopen(fd, "w");
    check(outstream != NULL, "Unable to open an outstream.");

    rc = fgetpos(outstream, &pos);
    check(rc != -1, "Failed to get position of outstream.");

    rc = fprintf(outstream, "It was written.");
    check(rc > 0, "Failed to write to outstream.");

    rc = fflush(outstream);
    check(rc != EOF, "Failed to flush outstream.");

    rc = fsetpos(outstream, &pos);
    check(rc != -1, "Failed to set outstream back to old position.");

    instream = fdopen(fd, "r");
    check(instream != NULL, "Unable to open an instream.");

    rewind(instream);
    lrc = ftell(instream);
    check(lrc == 0, "Failed to rewind instream.");

    out = fgets(buffer, 1023, instream);
    check(buffer != NULL, "Failed to read from instream.");

    printf("Read this from instream: \"%s\"\n", buffer);

    return 0;
error:
    return 1;
}