file io question

Hi all,

In the following code i am trying to give the user the option to print to a chosen text file if they choose to. I have been reading up on pointers and file io and am still lost.

Any help offered would be greatly appreciated.

thanks in advance.
Mike

Code:

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

void mysort(char word[][100], int size);

int  i, a, x=0, j=0;

void main()
{
char word[10][100];
	printf("this program will sort up to 10 words in alphabetical order\n");
	printf("if you have fewer than 10 words enter <ctrl> z twice\n\n");
	for(a=0; a<10; a++)
		{
		printf("enter a word\n");
		
		if(scanf("%s", word[x]) != 1) break;
		x=x+1;
		j=x;
		}
		x=0;

	printf("original words\n--------------\n");
	for (i=0; i<j; i++)
		{
		printf("%s \n", word[i]);
		}

	mysort (word, j);
	printf("\nsorted words\n------------\n");
	for (i = 0; i <j; i++)
		{
		printf("%s \n", word[i]);
		}

}
void mysort(char word[][100], int size)
{
	int pass, indx;
	char hold[100];
	for(pass = 0; pass < size - 1 ; pass++)
		{
		for(indx = 0; indx < size - pass - 1; indx++)
			{
			if(strcmp(word[indx], word[indx + 1]) >0)
				{
				strcpy(hold, word[indx]);
				strcpy(word[indx], word[indx +1]);
				strcpy(word[indx + 1], hold);
				}
			}
		}	
}

Here is a small sample program that prompts the user for a file name and prints "Hello World" to that file. It shouldn't take much to add this functionality to what you've got.

Code:

#include <stdio.h>

int main (void) {
   char file_name[20];
   FILE * output;

   printf ("Enter a file name: ");

   scanf ("&#37;s", file_name);

   output = fopen (file_name, "w");

   fprintf (output, "Hello World!\n");

   return 0;
}

If you use scanf() in that manner, you can't accept a filename with spaces. If you wish to allow spaces, either use fgets() (and trim off the newline char) or change scanf() to accept more appropriate input.

Several notes

1. void main should be int main
2. You don't need global vars - make them local in the main
3. You don't need both x and j - you can change the progem to use only one of them
4. Give your vars meaningfull names - not x, but wordCount for example
5. x=x+1 most peaple will write x++, it is more common notation for the same thing
6. You should work on your indentation - it will save you from some mistakes in the future

Thanks for you input guys,

Seems to be working. Now just need to figure out fgets().

Cheers,

Mike

Code:

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

int main(void)
{
	char buffer[BUFSIZ];
	size_t index;

	printf("Enter a string: ");
	fflush(stdout);
	fgets(buffer,sizeof(buffer),stdin);
	index = strlen(buffer) - 1;
	if(buffer[index] == '\n')
	{
		buffer[index] = '\0';
	}
	printf("You entered: <%s>\n",buffer);

	return 0;
}

Erhm . . . just don't type EOF (^Z for Windows) on a blank line. You'd be accessing buffer[(size_t)-1], which is almost certainly going to result in a segmentation fault. You could fix that by checking the return value of fgets(): fgets() returns NULL if it encountered EOF or another error before it stored any characters in the array.

I like this version:

Code:

#include <stdio.h>  /* for fgets(), printf(), puts(), and BUFSIZ */
#include <string.h>  /* for strchr() */

int main() {
    char buffer[BUFSIZ], *p;

    if(fgets(buffer, sizeof buffer, stdin)) {
        if((p = strchr(buffer, '\n'))) *p = 0;
        printf("You entered [&#37;s]\n", buffer);
    }
    else puts("No string entered");

    return 0;
}

There are many different ways to strip the newline from a string created by fgets(). These are just two of them.