Thread: Read from a file and find slope, midpoint, and distance

Its constantly saying that my code will not open will i have numbers in my file. I am used note pad and i saved my file as bacon.txt

Code:

#include <stdio.h>
#include <stdlib.h>

int main (void)
{
float x1;
float x2;
float y1;
float y2;
FILE*Fp;// file pointer
if((Fp=fopen("bacon.txt", "r"))==NULL)
{
puts("File would not open");
}
else
{
printf("%f%f%f%f\n", "x1", "y1", "x2","y2");
fscanf(Fp,"%f%f%f%f", &x1,&y1,&x2,&y2);
}
}

opens fine for me, BUT does have a warning about int main,

and a warning about gets, I would recommend changing gets() to a scanf()

and a warning about gets, I would recommend changing gets() to a scanf()

If your file name could have embedded spaces I would recommend using fgets() instead, be sure to remove the end of line character, if present. But never use gets() this function is so dangerous it has actually been removed from the current C standard.

Jim

how did you enter your file, like what was the name of your file

mine was bacon.txt

heres what im getting

Enter the name of file you wish to see
bacon.txt
Error while opening the file.
The contents of bacon.txt file are :
Segmentation fault

Code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
   char ch, file_name[100];
   FILE *fp;

   printf("Enter the name of file you wish to see\n");
   gets(file_name);

   fp = fopen(file_name,"r"); // read mode

   if( fp == NULL )
   {
      printf("Error while opening the file.\n");

   }

   printf("The contents of %s file are :\n", file_name);

   while( ( ch = fgetc(fp) ) != EOF )
      printf("%c",ch);

   fclose(fp);
   return 0;
}







                                                                                 [ Read 29 lines ]
  g++ read2.c
  ./a.out
Enter the name of file you wish to see
read.txt
Error while opening the file.
The contents of read.txt file are :
Segmentation fault

It still didnt work, I even made another note pad document with different numbers and name it read. I then typed in when prompted read.txt

and a warning about gets, I would recommend changing gets() to a scanf()

Terrible advice. Without adequate additions for protection, the second could be as bad as the first.

"fgets()" is usually best for getting a string input (see this FAQ).

For why "gets()" is bad, see here: FAQ > Why gets() is bad / Buffer Overflows - Cprogramming.com

In your latest example, you're not exiting if the file can't be read. You continue to try processing it, even if it failed to open.

And what compiler (and if applicable, IDE) are you using?
And where are you storing your text file?

It might simply not be in the right directory.

i am using ssh secure and I am storing it in my notepad my library documents saved as read

Originally Posted by ashley1nonly

i have windwos 8
i checked my pc
checked my local c
checked everything in my apps
checked everything in other shared computers and still didnt find it

Originally Posted by ashley1nonly

i am using ssh secure and I am storing it in my notepad my library documents saved as read

Wait...are you SSH'ing to another machine and compiling/running your code on the other machine? If so, the bacon.txt will be on that machine, not on your PC. You will have to edit the contents on that machine.

ok i went onto my transfer folder on ssh secure and i found the bacon.txt file and it did say hello world )))))))))))))))

when i am adding in my functions to find slope, distance, and midpoint where would i add them in my function

replaced the hello world with numbers and the numbers showed up.

how do i make the program read the values for x1 y1 x2 and y2. or will it automatically do that