Counting the number of lines in a text file - help

Hi all,

I wanted to write a program which will count the number of lines in a text file. And I tried to modify a example to do this. This is what I have written:

Code:

/* This program counts the lines in a text file */

#include <stdio.h>

#include <stdlib.h>

int main(int argc, char *argv[])

{
int ch;

FILE *fp;

long NumberOfLines = 0;


if (argc != 2)

{
printf ("Usage: %s filename\n", argv[0]);

exit(1);

}

if ((fp = fopen(argv[1], "r")) == NULL)

{
printf("Can`t open %s\n", argv[1]);

exit(1);

}

while ((ch = getc(fp)) != EOF)

{
if (ch = "\n") NumberOfLines++;
}

fclose(fp);

printf("File %s has %ld lines\n", argv[1], NumberOfLines);

return 0;


}

It doesn`t work. It counts the number of characters.

My question is how does the program understands when it comes to the end of the line? There`s EOF for end-of-file, is there sth similar for end-of-line?
Thanks in advance for your answers.

Have you tried 'fgetc', instead of 'getc'?

Using fgetc to control a while loop is not good practice - read the FAQ.

fgets() reads the file one line at a time, so just create a loop that counts the number of times fgets() returns something other than NULL pointer.

Code:

char line[1024];
NumberOfLines = 0;
while( fgets(line,sizeof(line),fp) != NULL)
   NumberOfLines++;

Code:

if (ch = "\n") NumberOfLines++;

Shouldn't this be:

Code:

if(ch == '\n')
   NumberOfLines++;

?

ahluka: I can't find what you're referring to in the FAQ's eerrrr.... couldn't give me a link could you ?

> Using fgetc to control a while loop is not good practice - read the FAQ.
That's feof(), not fgetc.
There's nothing wrong with the loop as posted.

> if (ch = "\n") NumberOfLines++;
1. use == not =
2. use '\n' for a char, "\n" is a 1-character string.

Everybody,
Thank you very much for your quick response. It was a great help for a novice like me.

Check This

http://www.cprogramming.com/challenges/countsol.html

I worked through the line counting challenge problem.

I almost have it but I am not clear on how I am to code for reading the file.
I keep getting the

cout<<"Input should be of the form 'count filename.txt'";

So I am not sure how to modify the code to read my file

file is named ten.txt (it has ten rows of characters.

any advice?

thanks
CS

Have you tried 'fgetc', instead of 'getc'?

They do the same thing, except getc is a macro, so don't use it for code that has side effects, like this:

Code:

getc(*s++);

cout is C++. What do you mean, you keep getting it?

[edit]Here's the feof() link: http://faq.cprogramming.com/cgi-bin/...&id=1043284351[/edit]

You mean you want to change

Code:

if ((fp = fopen(argv[1], "r")) == NULL)

into

Code:

if ((fp = fopen("ten.txt", "r")) == NULL)

Oh, I know what you mean by the cout now. It's in that other link. You need to run that sample program like this:

Code:

C:\DWK>count ten.txt