Thread: Help.. newbie for loop..stuck with the loop..

Hi all master,

question:
Write a C program to convert lines of input text to uppercase.
Do not use any standard library functions.
The program prompts the user to enter each line of text and does the conversion when the
text is entered. When an asterisk is entered, the program terminates. Assume that only
lowercase characters and space are entered.
Example execution (input text in italics):
Please enter text line: spiderman
SPIDERMAN
Please enter text line: sports car
SPORTS CAR
Please enter text line:*
HAVE A NICE DAY


Please kindly help me take a look for the program written below:
as i encountered problem with the loop..convert from small letter to upper letter without issue...

Code:

#include <stdio.h>

main()
{



	char c, d;
	int i;


	do{

	printf("Please enter text line:");

	  scanf("&#37;c",&c);


			d=(c&0x5f);
			printf("%c", d);
			

	}while(c!='*');



	printf("Have a good day\n\n");
}

Code:

d=(c&0x5f)

While that may work, I greatly prefer:

Code:

#include <ctype.h>
/* ... */
d = toupper(c);

You're also missing a closing curly brace (}) at the end of main().

You're also not going to be able to hold a line in a single character . . .

I suggest fgets(); or else print "Please enter text line" only when c is '\n'.

Might be a good idea to check for EOF too, in which case c would have to be an int.

[edit] Oh, and putchar() could be used instead of printf(). [/edit]

You're only reading one character at a time in the loop. So if you entered something like "tEXt*\n", you'd get

Code:

tPlease enter text line:ePlease enter text line:x\
Please enter text line:tPlease enter text line:*

for output. Probably not what you were looking for.

Print the "Please enter text line" message only when the user enters a '\n'. Or perhaps read in text line by line instead of character by character.

Like, have the program pause for 10 seconds? There's no portable way. See the FAQ, I think there's something on that in there.

You can use Sleep() from <windows.h>.

edited to include time delay I found at http://www.newton.dep.anl.gov/askasci/comp99/CS042.htm
Unfortunately a value of < 10 ..makes it pause for like 45 seconds from what I see.
<5 goes for about 9 seconds... if you need it precise then thats a different story. I bet it depends on your compiler too


Putting what the other person said..
I don't get what the c&0x5f does though...
My working equivalent based on the ascii table. by looking at Uppercase 'A' and Lower case 'a'
I don't believe I used a library function ... as long as you understand what you're code does..

if (c >='a' && c<='z')
d=(char)((int)c-32);
else
d=c;


Below seems to work decent..

Code:

#include <stdio.h>
#include <time.h>
main()
{
	char c=' ', d;
	  time_t start_time, cur_time;
int i;
 

printf("Please enter text line:");
	do{
if (c=='\n')
	printf("Please enter text line:");

	  scanf("&#37;c",&c);
	  	d=(c&0x5f);
	  	/*
	  	if (c >='a' && c<='z')
d=(char)((int)c-32);
*/
			printf("%c", d);
			

	}while(c!='*');
time(&start_time);	
	  do
         {
                 time(&cur_time);
         }
         while((cur_time - start_time) < 5);


	
	printf("Have a good day\n\n");
}

>I don't get what the c&0x5f does though...
It masks away the one bit difference between upper and lower case letters in the ASCII character set. It's kind of dicey though, because this doesn't account for non-latin alphabet characters. toupper is a much better choice because if the character doesn't have an upper case equivalent, it returns the character you passed.

>d=(char)((int)c-32);
Why all the casting?

Originally Posted by jochen

hi xsouldeath;


sorry for my poor understanding...

Code:

printf("Please enter text line:");

do{
if (c=='\n')
	printf("Please enter text line:");

is it mean when we press enter (new line), will print out ("Please enter text line:")?
cool.....


thanks all of u....

Yes,
You print "please enter text line: "
before looping and then you only want it to say enter a new text line when they enter the "\n" newline (i.e. PRESS ENTER KEY) character. I hope that clarifies it.
and Prelude has a point about unnecessary casting (d=c-32; ) works fine.
by the way to match the output above add (before the printf)
if (c!='*')
printf("&#37;c", d);
It would be a trickier special case if you had to allow strings like "Hi my name is *" to be entered, without exiting. i.e. exit only when the entire string entered is only "*".. but ya don't mind that.

>for the delay, is there any other method without use of library function..
Well, at this point all you have left without digging a little too deep is the crappy inaccurate way:

Code:

#define MAGIC_NUMBER 12345678

unsigned long x;

for ( x = 0; x < ULONG_MAX && x < MAGIC_NUMBER; x++ )
  ;