I can't enter any value when my program runned

NoWeDoR · 06-30-2015, 03:55 AM

I wrote a program in C/Linux but as in the picture I have an issue. How can I solve this?
Thanks for helps.

The picture is:

http://www.filedropper.com/screensho...15-06-30112909

My Codes are:

Code:

#include <stdio.h>

int main()
{
	FILE *ptrFILE;
	int lineNumber = 1, choice, i, totalLineNumber;
	char c;

	if ((ptrFILE = fopen("Test.txt", "r")) == NULL)
	{
		printf("File couldn't open..\n\n");
	}
	
	printf("*-* Content of file *-*\n\n");
	c = fgetc(ptrFILE);
	while (!feof(ptrFILE))
	{
		printf("%c", c);
		if (c == '\n')
		{
			lineNumber++;
		}
		c = fgetc(ptrFILE);
	}
	printf("\n\nTotal line number : %d\n\n\n\n", lineNumber);
	totalLineNumber = lineNumber;

	printf("Express the line number which you want to display (Enter positive value for at\nthe beginning or vice versa) : ");
	scanf("%d", &choice);
	printf("\n");
	if (choice > 0)
	{
		lineNumber = 0;
		fseek(ptrFILE, 0L, SEEK_SET);
		c = fgetc(ptrFILE);
		while (!feof(ptrFILE))
		{
			printf("%c", c);
			if (c == '\n')
			{
				lineNumber++;
				if (lineNumber == choice)
				{
					break;
				}
			}
			c = fgetc(ptrFILE);
		}
		printf("\n\n\n");
	}
	else if (choice < 0)
	{
		lineNumber = 0;
		fseek(ptrFILE, 0L, SEEK_SET);
		c = fgetc(ptrFILE);
		while (!feof(ptrFILE))
		{
			if (c == '\n')
			{
				lineNumber++;
			}
			if (lineNumber>totalLineNumber + choice)
			{
				printf("%c", c);
			}
			c = getc(ptrFILE);
		}
		printf("\n\n\n");
	}

	fclose(ptrFILE);
	return 0;
}

NevemTeve · 06-30-2015, 04:10 AM

I can't see the picture. Or the problem.
If you have problem with scanf, then try to debug:

Code:

	int rc;

        fprintf (stderr, "we are before 'scanf' be prepared\n");
        fflush (stderr);
        rc= scanf("%d", &choice);
        fprintf (stderr, "scanf returned %d (expected=1) choice=%d\n",
                 (int)rc, (int)choice);
        fflush (stderr);

HMW · 06-30-2015, 04:10 AM

The picture link doesn't work. Can you describe in words what your problem is, and what you expected please.

NoWeDoR · 06-30-2015, 04:15 AM

When I run this program, naturally it wants from me a value to enter... But I cannot enter any value

NevemTeve · 06-30-2015, 04:26 AM

> But I cannot enter any value

What is the obstacle?

NoWeDoR · 06-30-2015, 04:33 AM

A new link for the picture

http://www.megafileupload.com/8U5g/S..._09%281%29.png

HMW · 06-30-2015, 04:35 AM

I don't understand. When I compile your program it works fine:

Code:

gcc -Wall lqc.c -o lqc
lqc.c: In function ‘main’:
lqc.c:6: warning: unused variable ‘i’

As you see I only get a warning for an unused variable. Also, when I run the program it works fine (although it crashes with a segfault if there is no file to open - but that's not the issue at hand here):

Code:

./lqc 
*-* Content of file *-*

line1
line2


Total line number : 3



Express the line number which you want to display (Enter positive value for at
the beginning or vice versa) : 1

line1

I guess you're gonna have to be more specific about your issue.

HMW · 06-30-2015, 04:36 AM

Quote:

Originally Posted by NoWeDoR

A new link for the picture

http://www.megafileupload.com/8U5g/S..._09%281%29.png

You're gonna have to work on your screenshot skills buddy, still no picture!

NoWeDoR · 06-30-2015, 06:26 AM

The problem has been solved. I hadn't expressed the file's name correctly to program.

HMW · 06-30-2015, 08:24 AM

Quote:

Originally Posted by NoWeDoR

The problem has been solved. I hadn't expressed the file's name correctly to program.

Ok. Good. But you might want to change this:

Code:

	if ((ptrFILE = fopen("Test.txt", "r")) == NULL)
	{
		printf("File couldn't open..\n\n");
	}

Into something like this:

Code:

	if ((ptrFILE = fopen("Test.txt", "r")) == NULL)
	{
		printf("File couldn't open..\n\n");
                return 1; // <- You should exit the program here to avoid segfault and other nasty stuff!
	}