8 Common Programming Mistakes -
8 Common Programming Mistakes
Learning to program can be tough--just ask anyone who's done it! Fortunately, a lot of problems happen over and over again--I've put together 8 of the most common problems that you'll run into as a new programmer.
1. Undeclared Variables
int main()
"Huh? Why do I get an error?"
Your compiler doesn't know what x means. You need to declare it
as a variable.
int main()
2. Uninitialized variables
while(count&100)
"Why doesn't my program enter the while loop?"
In C++ variables are not initialized to zero. In the above snippet
of code, count could be any value in the range of int. It might,
for example, be 586, and in that situation the while loop's condition
would never be true. Perhaps the output of the program would be
to print the numbers from -1000 to 99. In that case, once again,
the variable was assigned a memory location with garbage data
that happened to evaluate to -1000.
Remember to initialize your variables.
3. Setting a variable to an uninitialized value
int sum=a+b;
cout&&"Enter two numbers to add: ";
cout&&"The sum is: "&&
Enter two numbers to add: 1 3
The sum is: -1393
"What's wrong with my program?"
Often beginning programmers believe that variables work like equations
- if you assign a variable to equal the result of an operation
on several other variables that whenever those variables change
(a and b in this example), the value of the variable will change.
In C++ assignment does not work this way: it's a one shot deal.
Once you assign a value to a variable, it's that value until you
reassign the values. In the example program, because a and b are
not initialized, sum will equal an unknown random number, no matter
what the user inputs.
To fix this error, move the addition step after the input line.
cout&&"Enter two numbers to add: ";
cout&&"The sum is: "&&
4. Using a single equal sign to check equality
char x='Y';
while(x='Y')
cout&&"Continue? (Y/N)";
"Why doesn't my loop ever end?"
If you use a single equal sign to check equality, your program
will instead assign the value on the right side of the expression
to the variable on the left hand side, and the result of this
statement is the value assigned. In this case, the value is 'Y', which is treated as true. Therefore, the loop will never end. Use ==
t furthermore, to avoid accidental assignment,
put variables on the right hand side of the expression and you'll
get a compiler error if you accidentally use a single equal sign
as you can't assign a value to something that isn't a variable.
char x='Y';
while('Y'==x)
cout&&"Continue? (Y/N)";
5. Undeclared Functions
int main()
void menu()
"Why do I get an error about menu being unknown?"
The compiler doesn't know what menu() stands for until you've
told it, and if you wait until after using it to tell it that
there's a function named menu, it will get confused. Always remember
to put either a prototype for the function or the entire definition
of the function above the first time you use the function.
void menu();
int main()
void menu()
6. Extra Semicolons
for(x=0; x&100; x++);
"Why does it output 100?"
You put in an extra semicolon. Remember, semicolons don't go after
if statements, loops, or function definitions. If you put one
in any of those places, your program will function improperly.
for(x=0; x&100; x++)
7. Overstepping array boundaries
int array[10];
for(int x=1; x&=10; x++)
cout&&array[x];
"Why doesn't it output the correct values?"
Arrays begin indexing at 0; they end indexing at length-1. For
example, if you have a ten element array, the first element is
at position zero and the last element is at position 9.
int array[10];
for(int x=0; x&10; x++)
cout&&array[x];
8. Misusing the && and || operators
}while(!(value==10) || !(value==20))
"Huh? Even though value is 10 the program loops. Why?"
Consider the only time the while loop condition could be false:
both value==10 and value==20 would have to be true so that the
negation of each would be false in order to make the || operation
return false. In fact, the statement given
it is always true that value is not equal to 10 or not equal to
20 as it can't be both values at once. Yet, if the intention is
for the program only to loop if value has neither the value of
ten nor the value of 20, it is necessary to use && : !(value==10)
&& !(value==20), which reads much more nicely: "if value is not
equal to 10 and value is not equal to 20", which means if value
is some number other than ten or twenty (and therein is the mistake
the programmer makes - he reads that it is when it is "this" or
"that", when he forgets that the "other than" applies to the entire
statement "ten or twenty" and not to the two terms - "ten", "twenty"
- individually). A quick bit of boolean algebra will help you
immensely: !(A || B) is the equivalent of !A && !B (Try it and
you can read more about this rule on Wikipedia: ). The sentence "value is other than [ten or twenty]" (brackets
added to show grouping) is translatable to !(value==10 || value==20),
and when you distribute the !, it becomes !(value==10) && !(value==20).
The proper way to rewrite the program:
}while(!(value==10) && !(value==20))
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大家还关注RabbitMQ - RabbitMQ URI Specification
RabbitMQ URI Specification
This specification defines an "amqp" URI scheme.
Conforming
URIs represent the information needed by AMQP 0-9-1 clients
as well as some RabbitMQ plugins to connect to RabbitMQ
1. Introduction
The scope of this
specification is limited to AMQP 0-9-1, the original protocol
implemented by RabbitMQ.
An AMQP 0-9-1 client connects
to a RabbitMQ node in order to publish and consume messages
according to the messaging model.
Several pieces of information are needed by a client to
establish and negotiate an AMQP 0-9-1 connection.
These connection parameters include:
The parameters needed to establish the underlying TCP/IP
connection to the server (i.e. host address and port).
Information to authenticate the client. AMQP 0-9-1 uses
for authentication.
Typically the PLAIN mechanism is
used, and so the authentication parameters consist of a
username and password.
The name of the "virtual host" (or vhost) that
specifies the namespace for entities (such as exchanges and queues)
referred to by the protocol. Note that this is not virtual
hosting in the HTTP sense.
A RabbitMQ client will typically obtain all these parameters
from a configuration file or environment variables in order
for it to set up the connection. So it is convenient if the
connection parameters can be combined into a single
character string, rather than as distinct configuration
settings. That means that only one configuration setting is
needed, and only one value has to be passed to the client
But combining the connection parameters into a single string
requires a convention, understood by the client
library, about exactly how the connection parameters are
represented and delimited. It is desirable to standardise
that convention, so that it may be implemented consistently
by many AMQP 0-9-1 client libraries. An obvious basis for such a
standard is the generic syntax for URIs defined in .
The purpose of this specification is to define the "amqp"
and "amqps" URI schemes which represent the AMQP 0-9-1
connection parameters within the generic URI syntax.
2. The "amqp" URI scheme
The syntax of an AMQP 0-9-1 URI is defined by the following ABNF
All names in these rules not defined here are taken
= "amqp://" amqp_authority [ "/" vhost ] [ "?" query ]
amqp_authority = [ amqp_userinfo "@" ] host [ ":" port ]
amqp_userinfo
= username [ ":" password ]
= *( unreserved / pct-encoded / sub-delims )
= *( unreserved / pct-encoded / sub-delims )
Once a URI has been successfully parsed according to this
syntax, the connection parameters are determined as
described in the following sections.
The host to which the underlying TCP connection is made is
determined from the host component according to RFC3986,
section 3.2.2.
Note that according to the ABNF, the host
component may not be absent, but it may be zero-length.
The port number to which the underlying TCP connection is
made is determined from the port component according to
The port component may be absent, indicated by the
lack of the ":" character separating it from the host.
it is absent, then the IANA-assigned port number for AMQP 0-9-1,
5672, should be substituted instead.
2.3. Username and password
If present, the username and password components should be
used in the SASL exchange that occurs via the
connection.secure and connection.secure-ok AMQP 0-9-1 methods.
Any percent-encoded octets in the username and password
should be decoded before they are used in the SASL exchange,
and the resulting octet sequences should be regarded as
UTF-8 encoded.
Both the username and pa their absence
is indicated by the lack of the "@" character separating the
amqp_userinfo from the host.
If the username is present,
the pa this is indicated by the lack of
the ":" character separating it from the username.
Zero-length usernames and passwords are not equivalent to
absent usernames and passwords.
RFC3986 states that "A password appearing within the
userinfo component is deprecated and should be considered an
error" (section 7.5).
While this is sound advice in the
context of user-facing applications (e.g. web browsers) and
for URIs that might be stored and displayed insecurely, it
is not necessarily valid for backend applications.
Many of those
applications are "headless" services, and open RabbitMQ connections on
behalf of the application as a whole rather than for
specific users. So the username and password identify the
application rather than a human user, and are likely to be
included with connection parameters appearing in a secure
store of configuration settings. User-facing
applications, which make RabbitMQ connections on behalf of
specific users, are also possible.
In such cases the
username and password may be provided by the user to
identify themselves.
But such applications are the
exception rather than the rule.
Thus authors of
applications implementing this specification should not
consider themselves bound by section 7.5 of RFC3986.
also see section 5 ("Security Considerations") below.
2.4. Vhost
The vhost component is used as the basis for the
virtual-host field of the connection.open AMQP 0-9-1 method.
percent-encoded octets in the vhost should be decoded before
the it is passed to the server.
Note that:
The vhost component of the URI does not include the
leading "/" character from the path.
This makes it possible
to refer to any vhost, not only those that begin with a "/"
character.
The vhost is a single segment.
Therefore, any "/"
characters that appear in the vhost name must be
percent-encoded. URIs with multi-segment paths do not obey
this specification.
The vhost com this is indicated by the
lack of a "/" character following the amqp_authority.
absent vhost component is not equivalent to an empty
(i.e. zero-length) vhost name.
3. Handling of absent components
Certain URI components (the port, username, password,
vhost and query) may be absent from a URI.
The host may not be
absent, but may be zero- for the purposes of this
section, a zero-length host is treated as absent.
Apart from the port (which is covered in the section 2.2
above), this specification does not mandate how
implementations should handle absent components.
approaches include, but are not limited to, the following:
An absent component may be substituted with a default
A user-facing application may prompt the user to provide
the value for an absent component.
An absent component may cause an error.
Furthermore, an application may follow different strategies
for different components.
For example, the URI "amqp://", in which all components are
absent, might result in an client library using a set
of defaults which correspond to a connection to a local RabbitMQ
server, authenticating as a guest user.
This would be
convenient for development purposes.
4. The "amqps" URI scheme
The "amqps" URI scheme is used to instruct a client
to make an secured connection to the server.
The AMQP 0-9-1 specification assume that the
underlying transport layer provides reliable
byte stream-oriented virtual circuits.
When it is not
necessary to secure the traffic on the network, TCP/IP
connections are typically used.
In cases where the traffic must be secured, TLS (see )
can be used.
Current practice is simply to layer AMQP
0-9-1 on top of TLS to form "AMQPS" (analogously to the
way HTTPS layers HTTP on top of TLS).
AMQP 0-9-1 does
not provide a way for a non-secured connection to be
upgraded to a secured connection. So a server that supports
both secured and non-secured connections must listen on
distinct ports for the two types of connections.
Apart from the scheme identifier, the syntax of the "amqps"
URI scheme is identical to that of the "amqp" URI scheme:
= "amqps://" amqp_authority [ "/" vhost ]
The interpretation of an amqps URI differs from the
corresponding "plain" URI in two ways. In all other respects,
the interpretation is the same.
The client must act as a TLS client, and begin the
TLS handshake as soon as the underlying TCP/IP connection
has been established. All AMQP 0-9-1 protocol data is sent as TLS
"application data".
Other than this, normal AMQP 0-9-1 behaviour
is followed.
If the port number is absent from the URI, the
IANA-assigned port number for "amqps", 5671, should be
5. Security Considerations
As discussed in the section 2.3 above, URIs will often
be supplied to applications as configuration settings.
such contexts, if the password cannot be incorporated into
the URI, then it will simply be supplied as a separate
configuration setting. This reduces the benefit of the use
of a URI without any increase in security. For this
reason, this specification overrides RFC3986's deprecation
of passwords within the userinfo component.
Developers should feel free use the password component
whenever this does not impact security.
Nonetheless, they
should be aware that the contents of the password component
may be sensitive, and they should avoid leaking it (e.g. the
full URI should not appear in exception messages or log
records, which might be visible to less privileged
personnel).
Appendix A: Examples
Below is a table of examples that show how URIs should be
parsed according to this specification.
Many of these
examples are intended to demonstrate edge cases in order to
elucidate the specification and provide test cases for code
that parses URIs. Each row shows a URI, and the resulting
octet sequences for each component.
Those octet sequences
are enclosed in double quotes. Empty cells indicate absent
components, as described in section 3.
amqp://user:pass@host:10000/vhost
amqp://user%61:%61pass@ho%61st:10000/v%2fhost
amqp://:@/
amqp://user@
amqp://user:pass@
amqp://host
amqp://:10000
amqp:///vhost
amqp://host/
amqp://host/%2f
amqp://[::1]
"[::1]" (i.e. the IPv6 address ::1)
Appendix B: Query parameters
Clients may require further parameterisation to define how
they should connect to servers. The standard URI query syntax
may be used to provide additional information to the client.
Query parameters may be more implementation-specific than other
URI as such this document will not attempt to prescribe
how they should be used. However, we have documented how the
officially supported clients read URI query parameters .From Wikipedia, the free encyclopedia
Novell, Inc.
was an American software and services company headquartered in . It had been instrumental in making
a focus for technology and software development. Novell technology contributed to the emergence of , which displaced the dominant
model and changed computing worldwide. Today, a primary focus of the company is on developing software for .
The company was originally an independent corporate entity until it was acquired as a wholly
this latter was acquired in 2014 by , of which Novell is now a division.
The company began in 1979 in
as Novell Data Systems Inc. (NDSI), a
manufacturer producing -based systems. Former
(ERI) employee
was the member of the original team that started Novell Data Systems. It was co-founded by George Canova, Darin Field, and Jack Davis. Victor V. Vurpillat brought the deal to , chairman of the board of Safeguard Scientifics, Inc., who provided the seed funding.
The company initially did not do well. The microcomputer produced by the company was comparatively weak against performance by competitors.
In order to compete on systems sales Novell Data Systems planned a program to link more than one microcomputer to operate together. The former ERI employees , Dale Neibaur and Kyle Powell, known as the
group, were hired to this task.
At ERI, Fairclough, Major, Neibaur and Powell had worked on government contracts for the Intelligent Systems Technology Project, and thereby gained an important insight into the
and related technologies, ideas which would become crucial to the foundation of Novell.
The Safeguard board then ordered Musser to shut Novell down. Musser contacted two Safeguard investors and investment bankers, Barry Rubenstein and Fred Dolin, who guaranteed to raise the necessary funds to continue the business as a software company as Novell Data Systems' networking program could work on computers from other companies.
Davis left Novell Data Systems in November 1981, followed by Canova in March 1982.
Rubinstein and Dolin, along with Jack Messman, interviewed and hired . The required funding was obtained through a rights offering to Safeguard shareholders, managed by the Cleveland brokerage house, Prescott, Ball and Turben, and guaranteed by Rubenstein and Dolin.
Major, Neibaur and Powell continued to support Novell through their
Software Group.
In January 1983, the company's name was shortened to Novell, Inc., and Raymond Noorda became the head of the firm. Later that same year, the company introduced its most significant product, the multi-
It is distributed by TriTech Distribution Limited in Hong Kong.
The first Novell product was a proprietary hardware server based on []
supporting six
ports per board for a maximum of four boards per server using a
cabling. A
(NIC) was developed for the IBM PC
(ISA) bus. The server was using the first
(NOS) called ShareNet. Later, ShareNet was ported to run on the
platform and renamed NetWare. The first commercial release of NetWare was version 1.5.
Novell based its
(XNS), and created its own standards from IDP and SPP, which it named
(SPX). File and print services ran on the
(NCP) over IPX, as did
NetWare uses Novell DOS (formerly ) as a boot loader. Novell DOS is similar to
, but no extra license for DOS this came from the acquisition of
in 1991. Novell had already acquired 's company , which manufactured smart
cards and commercialized the internet protocol , solidifying Novell's presence in these niche areas.
It was around this time also that
notoriety became involved with Novell. Tittel took up various positions within the newly acquired Excelan, becoming national marketing manager for Novell, before being named as Novell's director of technical marketing.
Novell did extremely well throughout the 1980s. It aggressively expanded its market share by selling the expensive
at cost. By 1990, Novell had an almost
position in NOS for any business requiring a network.
With this market leadership, Novell began to acquire and build services on top of its NetWare operating platform. These services extended NetWare's capabilities with such products as NetWare for SAA, Novell multi-protocol router,
However, Novell was also diversifying, moving away from its smaller users to target large corporations, although the company later attempted to refocus with NetWare for Small Business. It reduced investment in research and was slow to improve the product administration tools, although it was helped by the fact its products typically needed little "tweaking" — they just ran.
In June 1993, the company bought
from , acquiring rights to the
operating system, seemingly in an attempt to challenge . In 1994, Novell bought , as well as
from . These acquisitions did not last. In 1995, Novell assigned portions of its Unix business to the . WordPerfect and Quattro Pro were sold to
was also sold to
As Novell faced new competition, Noorda was replaced by
in 1994, and was followed by several CEOs who served short terms. One of Novell's major innovations at the time was Novell Directory Services (NDS), now known as . Introduced with
v4.0. eDirectory replaced the old Bindery server and user management technology employed by
and earlier.
In 1996, the company began a move into internet-enabled products, replacing reliance on the proprietary IPX protocol in favor of a native TCP/IP stack. The move was accelerated when
became CEO in 1997 and then Christopher Stone was brought in. The result was NetWare v5.0, released in October 1998, which leveraged and built upon eDirectory and introduced new functions, such as Novell Cluster Services (NCS, a replacement for SFT-III) and Novell Storage Services (NSS), a replacement for the Traditional/FAT filesystem used by earlier versions of NetWare. While NetWare v5.0 introduced native TCP/IP support into the NOS, IPX was still supported, allowing for smooth transitions between environments and avoiding the "forklift upgrades" frequently required by competing environments. Similarly, the Traditional/FAT file system remained a supported option.
Novell's decline and loss of market share accelerated under Eric Schmidt's leadership, with Novell experiencing industry-wide decline in sales and purchases of NetWare and a drop in share price of $40.00/share to $7.00/share.
The inclusion of
as a core system component in all mainstream PC operating systems after 1995 led to a steep decline in Novell's market share. Unlike
and its predecessors, ,
all included network functionality which greatly reduced demand for third-party products in this segment.
Analysts commented that the primary reason for Novell's demise was linked to its channel strategy and mismanagement of channel partners under 's leadership. Under Ray Noorda's leadership, Novell provided upgrades to resellers and customers in the same packaging as a newly purchased copy of NetWare, but at one third the cost, which created a "gray market" that allowed NetWare resellers to sell upgrades as newly purchased NetWare versions at full price periodically which Novell intentionally did not track. Ray Noorda commented to several analysts he devised this strategy to allow front line resellers to "punch through" the distributors like Tech Data and Ingram and acquire NetWare versions at a discounted rate where Novell "looked the other way" then allowed them to sell these versions as newly purchased NetWare versions in order to pay the Novell Field Support Technicians Salaries who for the most part were employees who worked for the front line resellers as Novell CNE (Certified NetWare Engineers).
Noorda commented that this strategy was one he learned as an executive at
when competing against imported home appliances, allow the resellers to "make more money off your product than someone else's". Eric Schmidt embarked on a disastrous strategy to remove the upgrades as whole box products without understanding Novell's channel dynamics, then directed Novell's general counsel to initiate litigation against a large number of Novell resellers who were routinely selling upgrades as newly purchased NetWare versions. Although this move bolstered Novell's revenue numbers for several quarters, Novell's channels subsequently collapsed with the majority of Novell's resellers dropping NetWare for fear of litigation.
By 1999, Novell had lost its dominant market position, and was continually being out-marketed by
as Novell's resellers dropped NetWare for fear of litigation, allowing Microsoft to gain access to corporate data centers by bypassing technical staff and selling directly to corporate executives. Most resellers then re-certified their Novell CNE employees as Microsoft MSCE technicians, the field support technicians who were Novell's primary contact in the field with direct customers, and were encouraged to make NetWare look second place with
features such as Group Policy. Microsoft's
was also more popular and looked more modern than the character-based Novell interfaces. With falling revenue, the company focused on net services and platform interoperability. Products such as eDirectory and GroupWise were made multi-platform.
In October 2000, Novell released a new product, dubbed DirXML, which was designed to synchronize data, often user information, between disparate directory and database systems. This product leveraged the speed and functionality of eDirectory to store information, and would later become the
and form the foundation of a core product set within Novell.
In July 2001, Novell acquired the consulting company , founded in
by , to expand offerings into services. Novell felt that the ability to offer solutions (a combination of software and services) was key to satisfying customer demand. The merger was apparently against the firm's software development culture, and the finance personnel at the firm also recommended against it. The CEO of CTP, Jack Messman, engineered the merger using his position as a board member of Novell since its inception and soon became CEO of Novell as well. He then hired back Chris Stone as vice chairman and CEO to set the course for Novell's strategy into open source and enterprise Linux. With the acquisition of CTP, Novell moved its headquarters to .
In July 2002, Novell acquired SilverStream Software, a leader in web services-oriented application, but a laggard in the marketplace. The business area called
tools based on .
In August 2003, Novell acquired , a developer of
applications (,
and ). This acquisition signaled Novell's plans to move its collective product set onto a .
In November 2003, Novell acquired , a developer of a leading , which led to a major shift of power in Linux distributions.
also invested $50 million to show support of the SuSE acquisition. Within the
project, Novell continues to contribute to SUSE Linux. openSUSE can be downloaded freely and is also available as boxed retail product.
In mid-2003, Novell released "Novell Enterprise Linux Services" (NNLS), which ported some of the services traditionally associated with
(SLES) version 8.
In November 2004, Novell released the Linux-based enterprise desktop
v9. This product was based on Ximian Desktop and SUSE Linux Professional 9.1. This was Novell's first attempt to get into the enterprise desktop market.
The successor product to , , was released in March 2005. OES offers all the services previously hosted by
v6.5, and added the choice of delivering those services using either a
v9 kernel. The release was aimed to persuade
customers to move to Linux.
From 2003 through 2005 Novell released many products across its portfolio, with the intention of arresting falling market share and to move away from dependencies on other Novell products, but the launches were not as successful as Novell had hoped. In late 2004, Chris Stone left the company after an apparent control issue with then Chairman Jack Messman. In an effort to cut costs, Novell announced a round of layoffs in late 2005. While revenue from its Linux business continued to grow, the growth was not fast enough to offset the decrease in revenue of . While the company's revenue was not falling rapidly, it wasn't growing, either. Lack of clear direction or effective management meant that Novell took longer than expected to complete its restructuring.
In June 2006, chief executive Jack Messman and chief finance officer Joseph Tibbetts were fired, with , Novell's president and chief operating officer, appointed chief executive, and Dana Russell, vice-president of finance and corporate controller, appointed interim CFO.
In August 2006, Novell released the SUSE Linux Enterprise 10 (SLE 10) series. SUSE Linux Enterprise Server was the first enterprise class Linux server to offer virtualization based on the
hypervisor. SUSE Linux Enterprise Desktop (popularly known as SLED) featured a new user-friendly GUI and -based 3D display capabilities. The release of SLE 10 was marketed with the phrase "Your Linux is Ready", meant to convey that Novell's Linux offerings were ready for the enterprise. In late September 2006 Novell announced a real time version of SLES called SUSE Linux Enterprise Real Time (SLERT) based on technology from .
In 2004, Novell sued , asserting it had engaged in antitrust violations regarding Novell's
business in 1994 through 1996. Novell's lawsuit was subsequently dismissed by the United States District Court in July 2012 after it concluded that the claims were without merit.
Despite this, on November 2, 2006, the two companies announced a joint patent agreement to cover their respective products. They also promised to work more closely, to improve compatibility of software, setting up a joint research facility. Executives of both companies expressed the hope that such cooperation will lead to better compatibility between
and better
techniques.
Microsoft CEO
said of the deal, "This set of agreements will really help bridge the divide between open-source and proprietary source software."
The deal involved upfront payment of $348 million from Microsoft to Novell for patent cooperation and
subscription. Additionally, Microsoft agreed to spend around $46 million yearly, over the next 5 years, for marketing and selling a combined SLES/Windows Server offering and related virtualization solutions, while Novell paid at least $40 million yearly to Microsoft, in the same period.
One of the first results of this partnership was that Novell adapted the
for use in OpenOffice.org.
Initial reaction from members of the
community over the patent protection was mostly critical, with expressions of concern that Novell had "sold out" and of doubt that the
would allow distribution of code, including the Linux kernel, under this exclusive agreement.
In a letter to the FOSS development community on November 9, 2006, , CTO of the
(SFLC), described the agreement as "worse than useless". In a separate development, the chairman of the SFLC, , reported that Novell had offered cooperation with the SFLC to permit a confidential audit to determine the compliance of the agreement with the
(version 2). , founder of the , said in November 2006 that changes coming with version 3 of the GPL would preclude such deals. When the final revision of the third version of the GPL license was decided, the deal between Microsoft and Novell was
in. A new clause will let companies like Novell distribute GPLv3 software even if they have made such patent partnerships in the past, as long as the partnership deal was made before March 28, 2007 (GPLv3 Section 11 paragraph 7).
On November 12, 2006, the
team expressed strong disapproval of the announcement and asked Novell to reconsider. The team includes an employee of Novell, , who confirmed in a comment on
that the statement was agreed on by all members of the team, and later quit his job at Novell in protest.
In early February 2007, Reuters reported that the Free Software Foundation had announced that it was reviewing Novell's right to sell Linux versions, and may even ban Novell from selling Linux, because of an agreement. However, Eben Moglen later said that he was quoted out of context. He was explaining that GPL version 3 would be designed to block similar deals in the future. Currently,[] Novell is not violating the GPL version 2 but the GPLv3 prevents such deals being made in the future. Microsoft has released two public covenants not to sue for the infringement of its patents when using Moonlight. The two covenants require the implementation to not be released in GPLv3.
In December 2009, Novell announced its intention to lead the market it identified as
(IWM). The company's products will enable customers to manage diverse workloads in a heterogeneous data center.
Novell had long been rumored to be a target for acquisition by a variety of other companies. On March 2, 2010, , L.P., an institutional investor with approximately 8.5% stock ownership of Novell, offered to acquire the company for $5.75 per share in cash, or $1 billion. On March 20, 2010, the company declined the offer and stated that the proposal was inadequate and that it undervalued the company's franchise and growth prospects.
Novell announced in November 2010 that it had agreed to be acquired by
for $2.2 billion. Attachmate plans to operate Novell as two units, one being . As part of the deal, 882
owned by Novell are planned to be sold to
LLC, a consortium of companies led by
and including , , and . According to Novell's SEC filing, the patents "relate primarily to enterprise-level computer systems management software, enterprise-level file management and collaboration software in addition to patents relevant to our identity and security management business, although it is possible that certain of such issued patents and patent applications read on a range of different software products". Additionally, the future owner anticipates no change to the relationship between the SUSE business and the openSUSE project as a result of this transaction.
On April 27, 2011, Novell announced that the merger with Attachmate had been completed, with Attachmate paying $6.10 per share in cash to acquire Novell. Immediately prior, Novell completed the sale of "certain identified issued patents and patent applications" to CPTN Holdings LLC for $450 million in cash. Novell became a wholly owned subsidiary of The Attachmate Group, the parent company of Attachmate Corporation.
The U.S. Department of Justice announced that in order to proceed with the first phase of their acquisition of certain patents and patent applications from Novell Inc., CPTN Holdings LLC and its owners altered their original agreements to address the department's antitrust concerns. The department said that, as originally proposed, the deal would jeopardize the ability of open source software, such as Linux, to continue to innovate and compete in the development and distribution of server, desktop, and mobile operating systems, middleware, and virtualization products. With regard to licensing the patents:
All of the Novell patents will be acquired subject to the GNU General Public License, Version 2, a widely adopted open-source license, and the Open Invention Network (OIN) License, a significant license for the Linux System
CPTN does not have the right to limit which of the patents, if any, are available under the OIN and
Neither CPTN nor its owners will make any statement or take any action with the purpose of influencing or encouraging either Novell or Attachmate to modify which of the patents are available under the OIN license
Concurrent with the closing of the acquisition, some of Novell's products and brands were transferred to another of
business units, , and the
brand was spun off as its own business unit. The fourth business unit, , was not directly affected by the acquisition.
On April 2011, Attachmate announced layoffs for the Novell workforce, including hundreds of employees from their
center, raising questions about the future of some open source projects such as .
In September 2014, mainframe software company , for $1.2 billion.
Cache Data Product (1986)
Softcraft (1987)
CXI (1988)
Excelan (1989)
International Business Software Ltd. (1992)
Netoria (1999)
Novetrix (1999)
JustOn (1999)
PGSoft (2000)
Novetrix (2001)
SilverStream Software (2002)
Salmon (2004)
Tally System (2005)
Immunix (2005)
e-Security, Inc (2006)
RedMojo (2007)
Senforce (2007)
and , () (2008)
Novell is organized into product development, sales, and services divisions with the following executive management team:
Kathleen Owens – President and General Manager
Dave Wilkes — Vice President, Engineering
Eric Varness — Vice President, Product Management and Marketing
Norman Rohde - Vice President, Sales for Europe, the Middle East, and Africa
Jon Hale — Vice President, North America Sales
Boris Ivancic — Vice President and General Manager, Asia Pacific
Ron Milton — Vice President, Global Services & Customer Value Realization
Sergio Toshio Mituiwa — Vice President and General Manager, Latin America
Katherine Tate — Vice President, Global Sales Operations
Novell products are organized into three categories:
Collaboration – The focus of this product group helps people connect with each other and work together. These products helps boost a customer's employee productivity, as individuals and teams. These collaboration offerings include:
Email, calendaring, contact management and task management
Team workspaces with doc management, workflows, and social streams
Mobile access:
Endpoint Management – The focus of this product group is to give customer's employees what they need to do their work, regardless of physical location. This group of products allows an IT staff can give the proper working environment to each person, and keep it updated remotely using a unified management console, device agent and database. The goal of these application, configuration, and
management products, make sure everyone's devices are:
Properly equipped
File & Networking Services – These products provide core file, print, and networking services. They offer a platform for networking in a mixed Windows/Linux/Mac environment. This group of products helps:
Control and automate file storage
Simplify network management
Enable users to install printers easily
Automate disaster recovery of key business systems
In addition to products, Novell also provides support, training, consulting and other services to its customers.
Novell has a wide array of web-based and phone-based support options for its customers. The Novell support website has repeatedly been named one of the "Ten Best Web Support Sites" by the Association of Support Professionals (ASP) and has been inducted into the ASP Hall of Fame. Novell received an Outstanding Website Award in the WebAward Competition for their Cool Solutions website with a searchable database of advice, tools and problem fixes submitted by users from all over the world.
Novell also hosts support forums covering all of their current and legacy products still within the support lifecycle including , ,
and . Novell offers users both
access to the support forums and a search option. While Novell encourages the use of these forums, it does not officially monitor these forums. The forums are maintained by Knowledge Partners that have a demonstrated competency with the various products and volunteer their time to try to help the wider community.
Novell maintains a number of wikis with up-to-date information on a number of its products. For instance, as new NetWare service packs are released the NetWare wiki is updated with tips and known issues with the service packs. In some cases, the service packs themselves will have their own wiki with information added from feedback provided in the support forums.
Novell is one of the first computer companies to provide certification to its products. They include:
Certified Linux Professional 10 (CLP 10)
Certified Linux Engineer 10 (CLE 10)
Products marketed by Novell include:
Novell iPrint Appliance a network print server supports mobility on printing, a user can print from any device from any where to anywhere in any corner of world
provides Internet access controls, secure VPN, and firewall services on NetWare
Business Continuity Clustering automates the configuration and management of high-availability, clustered servers
Client for Linux gives Linux desktop users access to NetWare and Open Enterprise Server services and applications
Novell Client|Client for Windows gives Microsoft Windows users access to NetWare and Open Enterprise Server services and applications
Cluster Services for Open Enterprise Server simplifies resource management on a Storage Area Network (SAN) and enables high-availability
Data Synchronizer keeps applications and mobile devices constantly in sync, and offers connectors for popular CRM systems
Endpoint Lifecycle Management Suite manages applications, devices, and servers over their life-cycle
Endpoint Protection Suite Endpoint Protection Suite
integrates three Novell products that work together to discover, analyze, provision, relocate and optimize file storage based on business policies
examines and reports on terabytes of unstructured file data, and forecasts storage growth
provides secure e-mail, calendaring, contact management, and task management with mobile synchronization
stores files for secure accessibility online and offline, across systems and on the web
NFS Gateway for NetWare 6.5 enables NetWare 6.5 servers to access UNIX and Linux NFS-exported file-systems
offers NetWare services like centralized server management and secure file storage, running on SUSE Linux Enterprise Server
Open Workgroup Suite provides a low-cost alternative to Microsoft Professional Desktop P features workgroup services and collaboration tools
Open Workgroup Suite for Small Business offers a full-featured desktop-to-server solution running on Linux, designed to support small business users
Service Desk streamlines and automates the provision of IT services. An OEM product from LiveTime Software.
provides automated management of file storage for users and work groups
Total Endpoint Management Suite efficiently balances security and productivity across an entire enterprise
provides secure team collaboration with document management and workflow features that can replace existing intranet systems
, a software suite supporting the
allows the packaging and deployment of virtualized applications with predictive application-streaming that delivers apps based on user behavior
ZENworks Asset Management provides reports on hardware and software, integrating licensing, installation, and usage data
ZENworks Configuration Management provides automated endpoint-management, software distribution, user support, and accelerated Windows 7 migration
ZENworks Endpoint Security Management (ZES) - provides identity-based protection for client
like laptops, smart phones, offers driver-level firewall protection
ZENworks Full Disk Encryption protects data on laptops and desktops
ZENworks Handheld Management allows securing stolen , protects user data, enforces password policies, and locks out lost or stolen devices
ZENworks Linux Management facilitates the control of Linux desktops and servers, using policy-driven automation to deploy, manage and maintain Linux resources
ZENworks Mobile Management secures and manages mobile devices, both corporate-issued and personal ()
ZENworks Patch Management automates patch assessment, monito monitors patch compliance to detect security vulnerabilities
ZENworks Virtual Appliance provides self-contained
configuration management, asset management and patch management
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See quote from , the Foundation's general counsel: "The community of people wants to do anything they can to interfere with this deal and all deals like it. They have every reason to be deeply concerned that this is the beginning of a significant patent aggression by Microsoft".
February 13, 2007, at the .
. Gplv3.fsf.org. June 26, .
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. Networkworld. March 20, 2010.
. . November 21, . Also on November 21, 2010, Novell entered into a Patent Purchase Agreement (the "Patent Purchase Agreement") with CPTN Holdings LLC, a Delaware limited liability company and consortium of technology companies organized by Microsoft Corporation ("CPTN"). The Patent Purchase Agreement provides that, upon the terms and subject to the conditions set forth in the Patent Purchase Agreement, Novell will sell to CPTN all of Novell's right, title and interest in 882 patents (the "Assigned Patents") for $450 million in cash (the "Patent Sale").
. Novell. November 22,
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. Attachmate Corporation. November 22,
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Koep, Paul (May 2, 2011). .
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. Novell Doc. Novell. ZENworks 11 SP3 Endpoint Security Management simplifies endpoint security by providing centralized management of security policies for your managed devices.
. . Novell. 2014. Novell ZENworks Endpoint Security Management utilizes an installed client application to enforce complete security on the endpoint itself.
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