🚀 go-pugleaf

csigjb@luxor.latrobe.edu.au () wrote:
>I have two C problems.
>
>PROBLEM 1 :
>
Snip....

I didn't try your program.  I can't answer question 1, but I can answer
question 2.

>PROBLEM 2 :
>
>const escape=27;
>const cr=13;
>const bs=8;
>
>while (ch!=cr)
>{
>     .
>     .
>     .
>}
>
>while (ch!=escape)
>{
>     .
>     .
>     .
>}
>
>If I replace the 27 with \27' or the 13 with '\13' then these loops don't
>work i.e. an infinite loop results. WHY?
>
>Also if I want to do somthing like this : puts("\24 \25"); which should
>print the up and down arrows on the screen (ASCII 24 and 25), but no, it
>prints some other ASCII characters. As far as I can tell C has its own
>unique character table, at least for the control characters. WHY?

C is not using a different character table.  The format string you are 
using is using a different radix.  According to my documentation, if you
specify an escape sequence in the format \nnn (where nnn is a 1 to 3 
digit number) the number is taken as an OCTAL number.  OCTAL 13 = decimal 
11 and OCTAL 27 = decimal 23.  Your program is looking for the wrong 
values.  You can also specify a number using hexadecimal notation by 
using the \xnn escape sequence (where nn is 1 or 2 hex digits).



>
>Sometimes I wonder whether some one needs to go back an rewrite the damn
>language so that it works sensibly and predictably like Pascal can be
>relied upon to do.

The language has been rewritten.  The rewrite is called C++.  The C++ 
language still allows you to build broken programs using the C syntax, 
but it is more strongly typed than plain C and adds new features that 
allow you to avoid many problems altogether (for example the << output
operator for the I/O classes simplifies formatted output and lets you get 
away from printf() and format strings).



-- 
***********************************************
Brian Hibbert  b_hibbert@csc32.enet.dec.com
Digital Equipment Corporation
All opinions expressed are my own and should
not be assumed to be the opinion of my employer