something about scanf() and FILE readed

[鄧名傑]

**if the origin FILE opened has following strings:
10,20,30,40,50,60,70
**I want to make them to an array x[n],and n is the amout number of the
FILE,as the example ,n is 7(n is not a const. so i CAN'T declare the correct
length of array before)
**But, my code only can get the first number 10, for when it encount ",",it
was terminated,what should I do?(help me please~)

/*=======================*/
int x[100];
i=0;
int chk,count;
do{
     count=0;
     
    chk =fscanf(fp,"%d",&x[i]);
    i++;count++} while(chk!=NULL);
int n=count;

[std10093]

I would suggest you to check fgets . The link comes with an example.

In standard C you can not learn the length of your data if it nos fixed.
(I mean you have to read the data to find out)

[Salem]

Try

    chk =fscanf(fp,"%d",&x[i]);
    fgetc(fp);  // burn a comma, newline or other single character.

[鄧名傑]

Thanks you,Salem , std10093^^ ,I am the beginner of C ,could you give me more detailed code for how should I do?

[std10093]

You checked the example from fgets? What did you not understand?

[鄧名傑]

I have modified my code ,could you help me debug it,THX >_<

/*=======================*/
int x[100];
i=0;
int chk,count;
char c;


do{
     count=0;
    c = fgetc (fp);
     x[i]=atoi(c);

      if (c == ',') i++;    } while (c != 'EOF');  

int n=count;

[std10093]

But you have not opened the file? Or you have done it and you did not post it?

c has to be an int because of EOF handling.As a result atoi has to be removed.

EOF is defined . You must remove the quotes.

Check this code. Read the comments.

/*=======================*/
#include <stdio.h>

int main(void)
{
    FILE* fp;
    /* I named the txt file test.txt */
    fp=fopen("test.txt","r");
    int x[100];
    int i=0;
    int count = 0;

    /* Read from file until EOF is reached */
    while(fscanf(fp,"%d",&x[i])!=EOF) {
         i++;    /* Increment by one the index of the array , */
         /* so that you do not overwrite what you just read   */

         /* Eat a comma , as salem said */
         fgetc(fp);

         /* Count how many numbers you read */
         count++;
    }

    for(i=0 ; i<count ; i++)
         printf("%d\n",x[i]); 

    /* Do not forget to close the stream */
    fclose(fp);

    return 0;
}

[laserlight]

Instead of using both i and count in the loop that reads the input, you might as well just use count since the current count will always be the index of the next element to be read into. Also, you should check that count < 100 before reading into x[count].

[std10093]

Instead of using both i and count in the loop that reads the input, you might as well just use count since the current count will always be the index of the next element to be read into. Also, you should check that count < 100 before reading into x[count].

I totally agree with laserlight. I was based on the user's code and did not think about it. Thank you.

[鄧名傑]

Thanks you so much