Sysadmin Ramblings

ipaddress to hostname without a single shred of error checking. This code will take an ipaddress as an argument and return the hostname associated with it using gethostbyaddr. It should have more error checking and a lot of other stuff, but this is just to show the base code. Cut and paste away. #include <unistd.h>
#include <netdb.h>
#include <netinet/in.h>

int main(int argc, char **argv) {
    struct hostent *hostname = malloc(sizeof(struct hostent));
    extern int h_errno;

    struct in_addr *ipaddr = malloc(sizeof(struct in_addr));
    ipaddr->s_addr=inet_addr(argv[1]) ;
    if ( (hostname = gethostbyaddr((char *) ipaddr,sizeof(ipaddr),AF_INET)) == NULL ) {
        printf ("%s\n","unknown");
        exit(1);
    }
    printf ("%s\n",hostname -> h_name);
}


Recently some laptops in our network stopped downloading virus definitions. Our firewall was configured to allow traffic from the wireless vlan to our server Read the rest of this entry »

There is an excellent package for working with an iPod on Linux. gtkpod. Since version 0.99.2 it supports importing of Video’s Read the rest of this entry »

My co-worker just got an iPod so I thought I would try and encode a DVD onto it (an unencrypted DVD that I own, for backup purposes only, not to be used for public performances, etc, only I looked at it, I shut it off when someone looked over my shoulder…blah blah). The ffmpeg that comes stock on RHEL4 is insufficient to do the transcoding. I built a newer version and mucked around a bit and got this going. I have a simple wrapper (there are numerous versions of such scripts floating around). Read the rest of this entry »

I purchased a Proxima DPP6850 off ebay. Because the projector is a few years old, it doesn’t have any component video capability. It has composite, s-video and two rgbvh (VGA) inputs.

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The Internet Control Message Protocol (ICMP) has many messages that are identified by a “type” field. I use the types to specify what actions to take in my custom iptables config. Read the rest of this entry »

Digital AV Out

To watch Gamecube games in progressive scan, you need to have a gamecube with digital out. Since 2004, Nintendo took the digital port off the gamecube. You can get your gamecube replaced with a model with the port directly from Nintendo.

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