understand "signing a cert" #open_q

A) understand the basics of "signing a msg"

B) understand the content of a cert
your name, your pub key

?

C) understand what it means to "sign a cert"
"treat the cert content as a message, and generate a digsig of it"

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to a novice programmer -- the importance of data structures in financial IT systems

Data structure is essential and non-trivial to every programming language on wall street -- java (collections), c++ (STL), python/perl (high-level data types)... A lot of algorithms (in the traditional, strict sense of the word) are created on or using classic data structures. There are a lot of jargons you need to grasp. Everyday programming requires you to be familiar with common operations on these data structures, but these are relatively straightforward. However, here are some of the non-trivial aspects of data structures and
algorithms

* sort python dict or tuple
* internals of hash table and ConcurrentHashMap
* STL container holding pointers
* STL pair
* STL stream iterators
* customize a sorted set/map for MyClass in C++, which is harder than java
* sort a map by value (real interview question) in java. Perl and python is easy.
* whiteboard-implement a blocking stack/queue (UBS)
* whiteboard-implement a basic hash table (MS)
* find top 99 in a large array (Barc) but no need to return them sorted
* choose array vs circular array vs linked list, in terms of memory efficiency (JPM).
* given 2 nodes in a binary tree, with no pointers except pointer-to-parent, find lowest common ancestor (Google)
* iterative tree walk (Barc)
* filtering iterator (MS)
* STL transform(), erase(), partition() etc
* STL allocators
* STL functors, binders
* STL iterator adaptors (back_inserter etc)




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Posted By familyman to learning finance,c++,py... <http://bigblog.tanbin.com/2011/05/to-novice-programmer-importance-of-data.html> at 5/03/2011 07:34:00 PM

hard edit vs soft edit when submitting order to mainframe

In one order entry system (A big European megabank), new orders are sent to mainframe. Upon validation, mainframe can return a message to the order entry system.

If the message is a hard edit, the order is rejected by mainframe validation module.

If  the message is a soft edit, the order is accepted by mainframe validation module. The soft edit is purely informational. Not necessarily a warning. No action is required on the user of the order entry system. I guess the soft edit is just "FYI".

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Posted By familyman to learning finance,c++,py... at 3/15/2011 11:52:00 PM

cobol copybook = input format spec

a cobol-copybook is "a file describing an input data format".

"cobol copybook" is the standard term ("cobol-layout" is less common) for files like that mentioned in https://ssl.kundenserver.de/shop.softproject.de/downloads/CobolCopybookToolkitForJava.pdf

"copybook-datatypes"
"copybook-dataclauses"

-- based on http://edocs.bea.com/JAM/v51/program/egenapp.html
A COBOL CICS or IMS mainframe application typically uses a copybook source file to define its data layout. This file is specified in a COPY directive within the LINKAGE SECTION of the source program for a CICS application, or in the WORKING-STORAGE SECTION of an IMS program. If the CICS or IMS application does not use a copybook file, you will have to create one from the data definition contained in the program source.

A copybook is conceptually (not technically) part of a cobol program. Usually this copybook is a standalone file, included from its parent-program.

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Posted By familyman to learning finance,c++,py... at 1/20/2008 08:53:00 PM

vbscript can ...

For localized/sandbox tasks like file processing or DB, xml..., perl and python are nice, but I feel vbscript is the dominant and standard choice for system automation. Vbscript integrates better into Windows. In contrast, on Linux/Unix, python and perl aren't stigmatized as 2nd-class-citizens

-- are based on [[automating windows administration]] --
access registry
connect to exchange/outlook to send/receive mails
regex
user account operations
**query group membership
**query Active Directory
**CRUD
file operations
** size
** delete folder
** read the version of a (DLL, EXE) file
** recursively find all files meeting a (size, mtime, atime..) criteria
** write into a text file

R-programming resources (ebooks ...

--ebooks (master copy is in USB drive)
There are also decent ebooks outside CRAN.


http://cran.r-project.org/doc/manuals/R-intro.pdf -- more techie
http://cran.r-project.org/doc/contrib/Ding-R-intro_cn.pdf

http://cran.r-project.org/doc/manuals/R-data.pdf -- includes excel integration
http://cran.r-project.org/doc/contrib/usingR.pdf -- good
http://cran.r-project.org/doc/contrib/Verzani-SimpleR.pdf -- more stats

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compressed content in a http response

Now I feel an http response may be a zip containing multiple files. The response "body" will be an compressed bytes array. (To avoid confusion, I will call this a "zip" rather than a "file".) When you parse these bytes, you may see multiple zip entries.

If you assume the entire zip is a single file and try to decompress/deflate it, it might fail. The output may be empty.

The http response also contains useful response headers. One of the headers would be content-type. The gzip and zip types seem to require different parsers.

imap advantage over pop3

Some say imap supports sending emails, while pop3 only supports receiving. I guess imap support for sending is limited.

Fairchild Semicon's IP traffic priority

Practical insight. Extremely useful to a company economizing on bandwith

Based on packet "protocol" [1], an IP router can give relative priorities to
Priority 1: voip packets
Priority 2: peoplesoft traffic
Priority 3: browser traffic
Proirity 4: lotus notes replication traffic

Lower priority packets are dropped more.

The most important browser traffic is, hold your breath, sales processing[2]. Sales staff use a web interface to process sales data. DB resides on another continent! In a rare but illustrative /incident/, lotus traffic ate into Priority 3 bandwidth and brought sales processing to a grinding slowdown.

As an alternative to a relatively fragile web interface, I suggested async messaging-based sales processing application. No clear answer.

[2] perhaps including but not limited to sales order
[1] packet headers on one layer of the envelopes

css selector clearly explained

http://www.btinternet.com/~wildfire/articles/11.htm

Q: what's a "selector", in one sentence of plain english?
A: bit of a CSS definition that says what the styles are applied to

Q: 3 basic types of selectors?
A:
* HTML Elements, such as <P> tags, <IMG> tags etc.
* Elements with a specific class, for example an element with the
class "mystyle" (<P CLASS="mystyle">)
* Elements with a specific ID, for example an element with the ID
"myparagraph" (<P ID="myparagraph">)

Q: pseudo selectors's signature, purpose, eg?
A: Examples of this are link states (unused, visited, active) and
first lines and letters. The selector has a colon after it with the
state before the definition. An example of this is the CSS definition
for changing the colours of link colours:

A:link {color:blue;}
A:visited {color:green;}
A:active {color:gold;}

Q: nested selector example?

Y K on T2000 vs E10k

Q: processing power?

A: E10k is old. About 400Mhz cpu. T2000 has more processing power.

 

Q: form factor?

A: E10k takes a full rack, with up to 16 boards, each holding up to 4 processors

 

Q: any special skill required to administer e10k or above?

A: not much different from mid-range sparc systems

 

ldap names

In LDAP, the situation is slightly more complicated. Names are built from components that are separated by commas (","). Like DNS names, they read from right to left. However, components in an LDAP name must be specified as name/value pairs. The name "cn=Todd Sundsted, o=ComFrame, c=US" names the person "cn=Todd Sundsted" in the organization "o=ComFrame, c=US." Likewise, the name "o=ComFrame, c=US" names the organization "o=ComFrame" in the country "c=US."