Question

So for this assignment I am supposed to read a file, and do things with the content. Right now I just want to be able to open the file, read it and print out how many lines it has. I believe I have the proper code to do so, but I have no idea how to “read” or connect to the file outside of my program! I am using the

FILE *fp = NULL; 
fp = fopen ();

part right? And that is how to open / connect to a file? But not sure what this does, and how it can connect to a file outside of the program. To read the file I have the user input their text file like

printf ("Enter the name of the data file: ");
scanf ("%[^\n]", &filename);

And then to read that I put

fp = fopen("&filename", "r");

but this doesn’t seem right and it doesn’t work. Can anyone explain what I am doing wrong, and how I can read a file that a user inputs? I am in an SSH matrix group if that makes sense, Like I log onto putty using an ssh terminal? Not sure how to explain it, but it’s my schools online SSH thing…

Answer 1

fp = fopen("&filename", "r");

filenameis variable , why are you passing it in "" double quotes.

Try something like this below:

char filename[50]; // need a character array or buffer to hold the filename

printf ("Enter the name of the data file: ");
scanf ("%[^\n]", filename);   // no & operator

now use

fp = fopen(filename, "r");   // filename variable should contain complete path 

                              //with the actual file name

I think this should work.

Also you need to check the fp as

if(fp == NULL)   // It's always a safe way to proceed
   printf("Error in file opening\n");