Free check programs software for linux

Programs Bar is a programs launcher bar theme for SuperKaramba.

Was tested on Mandriva 2006 and Fedora Core 5.

Check Your Network Address Translator for Compatibility with Peer-to-Peer Protocols.
If you are accessing the Internet from behind a Network Address Translator (NAT) of some kind, I would appreciate your help in surveying the behavior of different NATs, in terms of how and whether they support a certain technique for enabling peer-to-peer communication between NATted hosts (particularly when both endpoints are behind NATs). Down, you can understand what NAT is.
Suppose there are three communicating hosts: A, B, and C. Host A is a "well-known" Internet server with a permanent IP address, which acts as an "introducer" for the other two nodes. (For example, Host A might be a well-known ultrapeer or a game catalog server of some kind.) Host B, using Host As "introduction" services, would like to establish a direct peer-to-peer connection with host C. Both B and C, however, are behind (probably different) network address/port translators, and neither of them has exclusive use of any public IP address.
To initiate a peer-to-peer connection with host C, host B first sends A a message requesting an "introduction" to host C. A sends B a reply message containing Cs IP address and UDP port number as reported by host C, in addition to Cs IP address and UDP port number as observed by A. (If C is behind a NAT, then these two address/port combinations will be different.) At the same time, host A sends host C a message containing Bs IP address and UDP port numbers - again, both the ones reported by B and the ones observed by A, which will be different if B is behind a NAT.
Now B and C each know that they want to initiate a connection with each other, and they know each others public (NATted) as well as original IP addresses and UDP port numbers. Both B and C now start attempting to send UDP messages directly to each other, at each of the available addresses. If B and C happen to be behind the same NAT, then they will be able to communicate with each other directly using their "originally reported" IP addresses and UDP port numbers.
In the more common case where B and C are behind different NATs, the "originally reported" addresses will be useless because they will both be private IP addresses in different addressing domains. Instead, the IP address/UDP port combinations observed by A can be used in this case to establish direct communication. Although Bs NAT will initially filter out any UDP packets arriving from Cs public (NATted) UDP port directed at Bs public port, the first UDP message B sends to C will cause Bs NAT to open up a new UDP session keyed on Cs public port, allowing future incoming traffic from C to pass through the NAT to B. Similarly, the first few messages from B to C may be filtered out by Cs NAT, but will be able to start passing through the firewall as soon as Cs first message to B causes Cs NAT to open up a new session. In this way, each NAT is tricked into thinking that its respective internal host is the "initiator" of this new session, when in fact the session is fully symmetrical and was initiated (with As help) simultaneously in each direction.
Required NAT Behavior
There is one important requirement that the NATs must satisfy in order for this technique to work: the NATs must be designed so that they assign only one (public IP address, public UDP port) pair to each (internal IP address, internal UDP port) combination, rather than allocating and assigning a new public UDP port for each new UDP session. Recall that a "session" in Internet terminology is defined by the IP addresses and port numbers of both communicating endpoints, so host Bs communication with host A is considered to be one session while host Bs communication with host C is a different session. If Bs NAT, for example, assigns one public UDP port for Bs communication with A, and then assigns B a different public UDP port for the new session B tries to open up with C, then the above technique for peer-to-peer communication will not work because Cs messages to B will be directed to the wrong UDP port.
RFC 3022 explicitly allows and suggests that NATs behave in the former, "desirable" fashion, by maintaining a single (public IP, public port) mapping for a given (internal IP, internal port) combination independent of the number of active sessions involving this mapping. This behavior is not only good for compatibility with UDP applications, but it also helps to conserve the NATs scarce pool of public port numbers. Maintaining a consistent public port mapping does not adversely affect security in any way, either, because incoming traffic can still be filtered on a per-session basis regardless of how addresses are translated. There in fact appears to be no good reason not to implement the desirable behavior in a NAT, except perhaps for the implementation simplicity of naively allocating a new public port for every new session. Unfortunately, RFC 3022 does not require NATs to implement the desirable behavior, which has led me to wonder just how many real NATs actually do, and hence this page.
What NAT Check Does
The program natcheck.c is basically just a program that "pings" a well-known UDP port at two different servers that are publically accessible on the Internet. Both of these servers run the program natserver.c, with the command-line arguments "1" and "2" respectively. In addition, there a third "conspiring" server runs natserver with the command-line argument "3". Whenever each of the first two servers receives a UDP request, it not only sends a reply directly to the sender of that request, but also sends a message to the third server, which in turn "bounces" the reply back to the original client. The effect is that the client will receive not only solicited "ping" replies from the server the request was directed to, but also "unsolicited" replies from the third server.
To determine if the network address translator in use is implementing the desirable behavior of maintaining a single (public IP address, public port) mapping for a given (client IP address, client port), the client program natcheck.c basically just initiates a sequence of simultaneous pings to the first two servers (in case some of the requests or replies are lost in transit) and checks that the clients address and UDP port as reported by both servers is the same. If the NAT naively allocates a new public port for each new session, then the source port as reported by the two servers will be different, and its time to upgrade your NAT.
The replies echoed from the third server are used only to check whether the NAT properly filters out unsolicited incoming traffic on a per-session basis. Since the client never sends any messages to the third server, if the NAT is properly implementing firewall functionality, the client should never see the third servers echoed replies even after opening up active communication sessions with the first two servers.
Enhancements:
- The NAT Check client no longer attempts to guess whether you have Basic NAT or Network Address/Port Translation (NAPT). It turns to be quite difficult to test for this property reliably, because many NAPTs attempt to bind a private UDP port to a public port with the same port number if that port number is available, causing NAT Check to falsely report Basic NAT. The only way to test for this property reliably would be to run NAT Check on at least two client machines simultaneously, and since this property isnt terribly important to P2P apps its just not worth the trouble.
- The NAT Check client now tests for one additional NAT feature, which I call loopback translation. If a NAT supports loopback translation, it means that a host on the private network behind the NAT can communicate with other hosts on the same private network using public (translated) port bindings assigned by the NAT. Most NATs probably do not support this feature yet, but it may become increasingly important in the future where P2P clients may be located behind a common ISP-deployed NAT as well as individual home NATs. More details on loopback translation will appear in the next version of my Internet-Draft, to be released soon.
- The NAT Check client program now has a command-line option, "-v", which turns on verbose messages during the test.

fs-check program checks filesystem sizes to see if they are getting too full. It uses a configuration file that specifies the filesystems to check, email contacts, trigger thresholds (percentage or amount used/unused), and a report program to run.
Also included in the package is such a sample report program, fs-report. It shows things like the largest files, the newest files, and core files. It can be run from cron or as a daemon.
Both programs have a number of command-line options.
Enhancements:
- Various bugs have been fixed.
- This package will now build outside of the source tree.
- An option for specifying the default configuration file was added.
- Perl 5.006 or greater is now required.

rblcheck is a lightweight C program for doing checks against Paul Vixies MAPS Blackhole List and the ORBS open relay list. It works well in conjunction with Procmail for filtering unwanted and spamming bulk email.
The general idea behind RBL-style listings is rapid lookup of IP addresses using DNS (for example, for blacklisting IP addresses because of abuse). Each IP address is reversed and has a domain name attached to it; for example, the IP address 127.0.0.2 would become 2.0.0.127, and then a domain such as "relays.visi.com" would be added to it. You would then try to resolve the result (ie. 2.0.0.127.relays.visi.com); if you receive a positive reply, then you know that the address is listed. Further information can also be queried, such as text descriptions of why the address was listed.
Enhancements:
- Converted to automake/autoconf for configuration, which should make it easier to extend portability
- Added support for checking multiple addresses in one invokation.
- Added support for reading addresses to check from standard input, by specifying an argument of -.
- Changed rbl.dorkslayers.com to relays.orbs.org, due to a change in management.

Check Website is a performance monitoring and uptime notification tool. Check Website will check if a Website is up, and check the response time of the site.
The administrator can then choose to receive an email notification if the site is down, or if the site response time is too slow. All results are also written to a daily log file.
Enhancements:
- This release fixes some small bugs that caused hang ups in the program when checking Web sites.

Solving Constraint Integer Programs is a framework for constraint integer programming. For solving Integer Programs and Constraint Programs, a very similar technique is used: the problem is successively divided into smaller subproblems (branching) that are solved recursively.
On the other hand, Integer Programming and Constraint Programming have different strengths: Integer Programming uses LP relaxations and cutting planes to provide strong dual bounds, while Constraint Programming can handle arbitrary (non-linear) constraints and uses propagation to tighten the variables domains.
SCIP is a framework for Constraint Integer Programming oriented towards the needs of Mathematical Programming experts who want to have total control of the solution process and access detailed information down to the guts of the solver. SCIP can also be used as pure MIP solver or as framework for branch-cut-and-price.
Main features:
- It is a framework for branching, cutting, pricing, and propagation.
- It is highly flexible through many possible user plugins:
- constraint handlers to implement arbitrary constraints,
- variable pricers to dynamically create problem variables,
- domain propagators to apply constraint independent propagations on the variables domains,
- cut separators to apply cutting planes on the LP relaxation,
- relaxators to provide relaxations and dual bounds in addition to the LP relaxation,
- primal heuristics to search for feasible solutions with specific support for probing and diving,
- node selectors to guide the search,
- branching rules to split the problem into subproblems,
- presolvers to simplify the solved problem,
- file readers to parse different input file formats,
- event handlers to be informed on specific events, e.g., when a node was solved, a specific variable changed its bounds, or a new primal solution was found,
- display handlers to create additional columns in the solvers output.
- dialog handlers to extend the included command shell.
- Every existing unit is implemented as a plugin, leading to an interface flexible enough to meet the needs of most additional user extensions.
- A dynamic cut pool management is included.
- The user may mix preprocessed and active problem variables in expressions: they are automatically transformed to corresponding active problem variables.
- Arbitrarily many children per node can be created, and the different children can be arbitrarily defined.
- It has an open LP solver support (currently supporting ILOG CPLEX, Dash XPress-MP, SoPlex, and CLP.
- The LP relaxation need not to be solved at every single node (it can even be turned off completely, mimicing a pure constraint solver).
- Additional relaxations (e.g., semidefinite relaxations or Lagrangian relaxations) can be included, working in parallel or interleaved.
- Conflict analysis can be applied to learn from infeasible subproblems.
- Dynamic memory management reduces the number of operation system calls with automatic memory leakage detection in debug mode.
Enhancements:
- The new heuristics "RENS", "mutation", "veclendiving", and "intshifting", were included.
- The existing ones were improved.
- Presolving and c-MIR cut generation were improved.
- A few bugs were fixed.