How to find EOF through fscanf?

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I am reading matrix through file with the help of fscanf(). How can i find EOF? Even if i try to find EOF after every string caught in arr[] then also i am not able to find it.

with the help of count i am reading the input file

-12 23 3

1 2 4

int main()
{
    char arr[10],len;
    int count=0;

    FILE *input= fopen("input.txt", "r");

    while(count!=7)
    {   
           fscanf(input,"%s",arr);
          //storing the value of arr in some array.
                   len=strlen(arr);
           count++;

           if(arr[len+1]==EOF)
           printf("\ni caught it\n");//here we have to exit.
    }
return 0;
}

Instead of count i want to exit through the loop with the EOF . how can it be solved?

fscanf - "On success, the function returns the number of items successfully read. This count can match the expected number of readings or be less -even zero- in the case of a matching failure. In the case of an input failure before any data could be successfully read, EOF is returned."

So, instead of doing nothing with the return value like you are right now, you can check to see if it is == EOF.

You should check for EOF when you call fscanf, not check the array slot for EOF.

How to read until end of file C, fscanf, On success, this function returns the number of values read and on error or end of the file it returns EOF or -1 . The following program demonstrates how to use  The printf() statement is then user to print the data read from the file. The fscanf() keeps reading until EOF is encountered. When the end of file is encountered while condition becomes false and control comes out of the loop. In line 28, fclose() function is called to close the file.

while (fscanf(input,"%s",arr) != EOF && count!=7) {
  len=strlen(arr); 
  count++; 
}

fscanf() Function in C, Read To The EOF (End Of File). As examined in the previous example we can read to the end of the file with fscanf() function . We will use the  while (fscanf(in_fd, "%s", username) != EOF) { fprintf(out_fd, "%s ", username); } PS: Remember fscanf returns EOF in case of errors or if it reaches eof. So you can check return value of fscanf instead of feof().

If you have integers in your file fscanf returns 1 until integer occurs. For example:

FILE *in = fopen("./task.in", "r");
int length = 0;
int counter;
int sequence;

for ( int i = 0; i < 10; i++ ) {
    counter = fscanf(in, "%d", &sequence);
    if ( counter == 1 ) {
        length += 1;
    }
}

To find out the end of the file with symbols you can use EOF. For example:

char symbol;
FILE *in = fopen("./task.in", "r");

for ( ; fscanf(in, "%c", &symbol) != EOF; ) {
    printf("%c", symbol); 
}

How To Read Input with fscanf() function In C Programming, fscanf reads formatted input from the FILE designated by f according to the fscanf returns EOF if end of file (or an input error) occurs before any values are  Man, if you are using Windows, EOF is not reached by pressing enter, but by pressing Crtl+Z at the console. This will print "^Z", an indicator of EOF.

Function Descriptions : fscanf, for example.. number.txt: (has these contents) 1.75:2.00:3.00 many lines are in the file? or maybe its safe to say to loop the fscanf until EOF?) Pitfall to avoid: using char for the type of c. getchar returns the next character cast to an unsigned char and then to an int. This means that on most [sane] platforms the value of EOF and valid "char" values in c don't overlap so you won't ever accidentally detect EOF for a 'normal' char.

how do you loop fscanf until EOF in c?, If a file with this name already exists, erase it and create a new file. a. Open a file for appending (writing at end of file). Create the file if it doesn  It means that the way the feof() function (and other functionality with regards to EOF in general) is used is often misunderstood and wrong. So is your code. First, fscanf() doesn't always do what you think it does, and getting lines from a file is better performed using fgets().

[PDF] 5. Reading and Writing Files Using the fprintf and fscanf , The fscanf() function cannot be used for a file opened with type=record or the end of the string pointed to by buffer is equivalent to fscanf() reaching EOF. If fscanf fails (returns 0), then data[i] will remain unassigned. – user694733 Jan 30 '15 at 10:06 Because you failed to read the documentation for the language features that you use. – Lightness Races with Monica Jan 30 '15 at 10:46

Comments
  • we have provided only input matrix , so obviously count is not given. In the program it is taken as i am not able to find the EOF through fscanf
  • while(fscanf(input,"%s",arr) != EOF) { fscanf(input,"%s",arr); len=strlen(arr); printf("%s\t",arr); }
  • then how it is possible to stop at EOF through fscanf ?
  • What do you mean? Many people in this thread have demonstrated how to stop when fscanf returns EOF. The answer below, the comment above...something like: while(fscanf(input,"%s",arr) != EOF) {...}. When the end of the file is reached, fscanf will return EOF, which the while loop will catch, and no more stuff will be read. In fact, you can use this to calculate your count variable.
  • we have provided only input matrix , so obviously count is not given. In the program it is taken as i am not able to find the EOF through fscanf .
  • @aakasha:- just strike it away ;)
  • How you can do it, without a count ??