Infinite loop output problem

[Jonyb222]

Hi, I'm having trouble with a java program I was tasked with converting to C, the original program take an in.txt file filled with rougthly a paragraph's worth or words, each on it's own line and outputs to a out.txt file the same words now on consistent lines no longer than 50 chars, however my current code, only adds a space to each line and then repeats the last word forever, causing me many headaches...

#include <stdio.h>
#include <string.h>

int main()
{



int LINE_SIZE = 50;  // this will decide how long our lines can be
int Position;
char InputLine[50];


//Creates the pointers needed to reference our files
FILE *FileIn;
FILE *FileOut;


//open the files
FileIn=fopen("in.txt","r"); 
FileOut=fopen("out.txt","w");

//check to see if they opened correctly
if(FileIn==NULL) 
{
printf("Error: can't open the input file.\n");
}

if(FileOut==NULL) 
{
printf("Error: can't open the output file.\n");
}

//reads one line at a time from in.txt
fscanf(FileIn, "%s", &InputLine); 


//I know the "Position != feof(FileIn)" is wrong but I'm unsure as to what should go there, would it be "InputLine != feof(FileIn)"?

	for (Position=1; Position != feof(FileIn); Position++)  
	{

		if (InputLine == (NULL))  

// I suspect this is also causing some trouble, it's supposed to check to see if i'm at the end of the line, the original program had ("") instead of NULL but that didn't work

		{

			if (Position > 1)
			{
			fprintf(FileOut, "\n");
			}

		fprintf(FileOut, "\n");
		Position = 1;
		}

		else
        	{
//checks to see if my current line is over the 50 char limit
          	if ((Position+(strlen(InputLine))-1) > LINE_SIZE)
          	{
            	fprintf(FileOut, "\n");
            	Position = 1;
          	}
// print the word to out.txt in the correct format
		fprintf (FileOut, "%s\n", InputLine);
          
		Position += (strlen(InputLine));

			if (Position <= LINE_SIZE)
         		{
          		fprintf (FileOut, " ");
          	  	Position++;
			}
        	}

		fscanf(FileIn, "%s", &InputLine); 
	}

	fclose(FileIn); 
	fclose(FileOut);

I want to learn from my mistakes so please point me in the right direction, I'd rather write the correct code myself instead of having it handed to me

[quzah]

 Position != feof(FileIn);

That's wrong. feof shouldn't be used before something has actually been read, and, that return value comparison isn't what you want.

if (InputLine == (NULL))

Arrays can never be NULL.


Quzah.

[Jonyb222]

ok. but would "InputLine != feof(FileIn)" be any better to check when I've hit the end of the file? (and therefore stop it from repeat the last word over and over again)

if it helps any here is the original programs code:



import java.io.*;

public class Pretty
{
  public static final int LINE_SIZE = 50;
  
  public static void main(String[] parms)
  {
    BufferedReader fileIn;
    PrintWriter fileOut;
    String inputLine;
    int position;
    
    try
    {
      fileIn = new BufferedReader(new FileReader("in.txt"));
      fileOut = new PrintWriter(new FileWriter("out.txt"));
      
      inputLine = fileIn.readLine();
      position = 1;
      while (inputLine != null)
      {
        if (inputLine.equals(""))
        {
          if (position > 1)
          {
            fileOut.println();
          }
          
          fileOut.println();
          position = 1;
        }
        
        else
        {
          if ((position+inputLine.length()-1) > LINE_SIZE)
          {
            fileOut.println();
            position = 1;
          }
          fileOut.print(inputLine);
          
          position += inputLine.length();
          if (position <= LINE_SIZE)
          {	// add a blank after the current word
            fileOut.print(" ");
            position++;
          }
        }
        
        inputLine = fileIn.readLine();
      }
      
      fileIn.close();
      fileOut.close();
    }
    
    catch (IOException ioe)
    {
      System.out.println(ioe.getMessage());
      ioe.printStackTrace();
    }
  }
}

[MK27]

ok. but would "InputLine != feof(FileIn)" be any better to check when I've hit the end of the file?

No, that actually does not make much syntactical, much less logical, sense.

This

char InputLine[50];

can never be tested as NULL unless you reassign the signifier (which would be stupid, and fortunately you do not).

Vis. the end of the file, fscanf() will return EOF.

while ((fscanf("%s",InputLine))!=EOF)

Keep in mind that the return value of fscanf IS NOT placed into InputLine.

And DON'T USE & with %s and a character array.

[Jonyb222]

And DON'T USE & with %s and a character array.

ummm... could an fgets possibly improve my situation?

fgets(InputLine, 49, FileIn);

and would this be the proper implementation for the rest of the code?

Position = 1;
	while ((fscanf("%s",InputLine))!=EOF)
	{

		if (InputLine == (""))
		{

			if (Position > 1)
			{
			fprintf(FileOut, "\n");
			}

		fprintf(FileOut, "\n");
		Position = 1;
		}

		else
        	{
          	if ((Position+(strlen(InputLine))-1) > LINE_SIZE)
          	{
            	fprintf(FileOut, "\n");
            	Position = 1;
          	}
		fprintf (FileOut, "%s\n", InputLine);
          
		Position += (strlen(InputLine));

			if (Position <= LINE_SIZE)
         		{
          		fprintf (FileOut, " ");
          	  	Position++;
			}
        	}

		fscanf(FileIn, "%s", &InputLine); 
	}

	//The end has come, repent sinners, REPENT!!!
	fclose(FileIn); 
	fclose(FileOut);

}

*edit* in between classes I was able to compile my new version of my code but unfortunatly I receive this:
59: warning: passing argument 1 of ‘fscanf’ from incompatible pointer type

while ((fscanf("%s",InputLine))!=EOF)

and when I run it afterwards I receive a bus error

any ideas on how to proceed?

[tabstop]

There are such things as books/manuals. Look up what the arguments to fscanf are.