[OT] difference of Scripting and programming

[John Summerfied]

|TF20|Shockwave wrote:

> 
> 
> The line between a script and a program is certainly a blurred one.  I would
> argue that a script is *usually* considered less complex than a program.
> Additionally, scripts organize instructions just as programs do, but they
> cannot create new instructions to be executed.  Programs can.  

Eh?
[summer at bilby ~]$ file /sbin/install*
/sbin/install-info:  ELF 32-bit LSB executable, Intel 80386, version 1 
(SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), not 
stripped
/sbin/installkernel: Bourne shell script text executable
[summer at bilby ~]$

I'd thought the latter is an instruction: it gets run when one installs 
a new kernel.

 > Robustness
> and complexity are usually what separate the two.

Robustness is always essential, in programs of any kind.

Complexity is in the eye of the beholder:) Apart from that, an an 
important part of designing a program is to break down complexity into 
manageable components.

Writing a program from scratch that uses indexed files is immensely 
complex, if done in machine language.

It's easier, but still a formidable task in an assembly language.

Many find it achievable in a language such as C++, PL/1, COBOL etc, but 
it's still easier to produce an unmaintainable mess than to create a 
work of art that will stand the test of time.

However, using a relational DBMS such as postgresql or Oracle or DB2, 
with an SQL interface and it becomes a doddle. One can even do it in 
shell scripts.

The complexity is removed from the task at hand by using pre-existing 
code (the RDMS and your chosen shell and maybe some other programs).

For example, it's quite easy to approach finance.yahoo.com and get 
prices for a selection of securities using lynx, to strip out the junk 
with grep and awk and to stuff the prices into a postgresql database. A 
few hours' work at most.

Then, one can extract numbers from the database, again using shell 
scripts, and create reports, or import files for a spreadsheet, or input 
files for gnuplot to prepare pretty pictures.

If one did the whole thing in C or Java, one would have to have a 
working knowledge of HTTP, maybe some HTML (to parse the results), how 
to use ODBC (JDBC) and how to do graphics in C (Java).

It would be weeks or months, and probably relatively buggy. Might run 
faster though.




> 
> I've always thought of it like the difference between squares and
> rectangles.  All squares are rectangles, but not all rectangles are squares.
> Similarly, all programs can be considered scripts, but not all scripts can
> be considered programs.  ;)

Yer back to front here.


> 
> 
> Shockwave
> 


-- 

Cheers
John

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