run-time errors ~~

My program has a lot of run-time errrors,but I don't know how to correct it after I debugged and looked through it.My program is an analyzer.It has problem on finding the longest word and the font colour. I feel so upsad with my program.Can anyone help me,please?

Code:

scanf("%s",filename);

Bad. Read my signature for more information.

Code:

pfile = fopen(strcat(filename,".txt\0"),"r");

Confusing to the end user. You say enter a filename but automatically append .txt, even with no mention of so. You don't even check if there even IS a .txt extension in the inputted filename either.

Code:

a = fgetc(pfile);

fgetc returns int, but a is char. This causes a warning. I suggest you redeclare all those variables to int instead.

Code:

if(a==' '||(a>32&&a<48)||(a>57&&a<65)||a=='\n')
{
	words++;
	if(b==' '||b<65||(b>90&&b<97)||b>122)
		words--;
}

What's this mess? How am I supposed to know what ASCII value 32 is? Use string liters, such as '\n', ' ', etc, like you've done a little already.

Code:

while(ch1!=EOF)
{
	count = '.';
	count++;
}

What's this supposed to do? It does nothing, except an infinite loop!

Code:

while(y!=EOF)
{
	x = '\n';
	x++;
}

Same here... infinite loop.

Code:

while(n!=EOF)
{
	z = '?';
	z++;
}

Same here... infinite loop.

Perhaps you should try to actually fix your code first.

Besides these,I still encounter some problems.First of all,the program stopped after I input the filename.It didn't work afterwards,howcome?Are there something that affects it?

Infinite loop.
Have you fixed these problems yet? If not, then try to do so before moving on.

I have made quite many changes,but it still stuck.Can you find what is the problem with that?I just took a little function out as most of my functions are in the same structure.

Code:

pfile = fileopen();
     punct = 0;
     ch = fgetc(pfile); 
     do{
         if( ch == '.' ||ch==','||ch=='!'||ch=='?'||ch=='('||ch==')'||ch==';')
             punct++; 
        }while(ch!=EOF);
            
        return punct;

You only call fgetc() once. You need to call it in the loop.

Do you mean I have to put this(ch=fgetc(pfile))in the loop?Where?

Come on, read your loop.
If ch is . , ! ? ( ) or ;, then increase punct by one.
Loop.
Check the ch value AGAIN.
You're just comparing the same data over and over.

We aren't going to do your work for you, so you'll actually need to analyze your code, understand it and understand what you actually have to do to make it work.
Before writing something, you must have a clear picture on how you are going to do it.
Is it going to read a character, compare it to see if it matches what you want and increase the counter if it does?

Well, I'll leave the rest to you. You should be able to figure it out.

Sounds like someone should look up and learn flowcharts.

While they may seem very pointless, they're in-fact not.

off topic/
Goodness Elysia's signature is large... and not just largely full of lies
/off topic

I encounter another problem again.I have corrected the loop as laserlight taught.My function only works when it is in single.If I combine the functions together,it doesn't work.Why?

Post your code.

I just add the fgetc into the loop.It works only when the program has only this function with the fileopen.

Code:

     
     pfile = fileopen();
     punct = 0;
     ch = fgetc(pfile); 
     while(ch!=EOF){
         ch = fgetc(pfile);
         if( ch == '.' ||ch==','||ch=='!'||ch=='?'||ch=='('||ch==')'||ch==';'||ch=='"')
             punct++; 
        }
        fclose(pfile);    
        return punct;

Then perhaps you might want to explain what you mean by

My function only works when it is in single.If I combine the functions together,it doesn't work.Why?

?

Also, if you don't know, you do two fgetc in a row without checking the result.
Do you actually understand what you're doing here?

What I mean is the above function only works properly while it is used with the file function (of course also the main program).I don't really know how to solve this error.I feel very hesitating and helpless with that.I know that fgetc will read the characters until EOF while fgets will sudden stop,so I use getc instead of fgets.What should I do the next step then?

Fgetc reads one character from the file. Fgets reads one line from the file.
Both functions stop if they try to read beyond the end of the file, in which case fgetc will return EOF but fgets will fail and return 0 and feof on your FILE* pointer will return true.

Try to read your code and see what it actually does. You can't guess what it does and rely on others to tell you what's wrong. If you do, you will most certainly fail any class and you'll never be a real program (whichever applies).