Entering and splitting string

Hello. I have a problem trying to split and store specific string.
When user enters: Name1 10, Name 2 15, Name 3 40 I have to split it and store Names and age for other actions - like name sorting. So I have the problem of how to split and store the information correctly.

Code:

---

char *buf=(char*)malloc(MAX);
    fflush(stdin);
    char data[MAX];
    char name_age[MAX];
    system("cls");
    printf("Enter name and age:\n");
    gets(buf);
    strcpy(data, buf);
    fflush(stdin);
    char delims[] = ", ";
    char *result = NULL;
    result = strtok(data, delims);
    while(result != NULL) {
        printf("Entered information: %s\n", result);
        result = strtok(NULL, delims);
    }

---

Can you help me with this. I found the strtok() function and separated the string to:
Name1 20
Name2 30
and so on

but I can't figure out how to store the information and use it afterwards.

I'll appreciate any help.

fflush(stdin) is undefined - read FAQ.
gets is unsafe. Use fgets instead.

You can strtok() it into
Name1 20
Name2 30
and so on
Then strtok() each of those into the names and ages.
Don't use fflush(stdin);
Also, system("cls"); is not secure

system itself is unportable (due to that it simply executes OS specific programs), and how to clear the screen is also covered in the FAQ.

Thanks for your replies, guys. But can you give me help about how to store the string I've split and post-split it? That's what I can't find out. I'm not so good at C, so I don't know what's the best way to store and use the stored string after that.

If I split it to name / age I think I'll be able to get, for example, the average age or sort the names alphabetically.

One way would be to use a pointer to keep track of the position in your buffer, then search for ' ' or ',' and from that, extract the strings using memcpy.

Here's some psuedocode of how I'd solve this problem:

Code:

---

struct PERSON
{
    char name[MAX];
    int age;
};

/************* inside the main() function *************/
char data[MAX], name_and_age[MAX];
PERSON names_and_ages[MAX];
// Get the input
count = 0;
while (GetMoreData(data, name_and_age))
{
    names_and_ages[count] = SeparateNameAndAge(name_and_age);
    count++;
}

// The GetMoreData function:
bool GetMoreData(char data[], char name_and_age[])
{
    name_and_age = strtok(data, delim);
    // if strtok didn't work return false

    return true;
}

// The SeparateNameAndAge function
PERSON SeparateNameAndAge(char name_and_age[])
{
    PERSON person;
    // strtok the name: person.name
    // strtok and convert the age: person.age
    return person;
}

---

Declaring variables in the middle of a block is C99 and should be avoided in C89 programs. In addition, casting malloc() is generally a bad idea.

Here's one way to do it, with sscanf().

Code:

---

    char delims[] = ", ", *result = NULL;
    char name[MAX];
    int age;
    result = strtok(data, delims);
    while(result != NULL) {
        sscanf(result, "%s%d", name, &age);
        printf("Name: %s\tAge: %d\n", name, age);
        result = strtok(NULL, delims);
    }

---

dwks, your code gave me strange result. Age was at the place of Name and for Age there were quite big numbers - like 2101215 and so.

Brad0407, I'm trying currently to use your suggestion for solving the problem, but I don't know if I'll be able to work it out.

That splitting just stops me... I'm unable to continue with the next processing.

Yes, of course, sorry, I forgot to eliminate the space from the list of delimiters. Here's a full working example.

Code:

---

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

void splitname(char *string) {
    const char *delim = ",", *next;
    char name[BUFSIZ];
    int age;

    for(next = strtok(string, delim); next; next = strtok(NULL, delim)) {
        sscanf(next, "&#37;s%d", name, &age);
        printf("Name: \"%s\", age: %d\n", name, age);
    }
}

int main(void) {
    char data[] = "Joe 10, Sam 20, Tim 40, Buckministerfullerine 80";

    splitname(data);

    return 0;
}

---

Output:

Code:

---

Name: "Joe", age: 10
Name: "Sam", age: 20
Name: "Tim", age: 40
Name: "Buckministerfullerine", age: 80

---

dwks, thank you very much! It works perfectly! That's exactly how it should work. :)

Can you help me just e little bit? I know how to store the age in an array and how to sort it and so on, but how can I store the names and sort them too?

Well, it's not that much different from dealing with ages (numbers). You have to use a multi-dimensional array, however, much like this:

Code:

---

int numberarray[ELEMENTS];
char stringarray[ELEMENTS][MAX_STRING_LENGTH];

---

And when sorting strings, you need to use strcmp() to determine which string comes "before" another string.

Try it out, see what happens. Get the number (age) code working first, and it should be a simple modification.

Ok, so I made

Code:

---

int ages[50];
int c = 0;

---

and in the for loop

Code:

---

ages[c] = age;

---

After that, when I printf age it is ok, I use another for loop and it prints all the ages.

I also created

Code:

---

char names[50][20];

---

but I can't figure out how to fill it in. I understand that it must be

Code:

---

names[0][John]
names[1][Mark]

---

and I fill the number with c (like ages[c]), but don't know how to fill in the name.

Use strcpy().

Code:

---

strcpy(names[c], the_latest_name);
c ++;

---

Or something like that.

And don't forget to #include <string.h>.

dwks, I appreciate your help very much. Thank you.

I added a struct to keep the names and age, so I can easily display them after that.
Tomorrow I'll try to make it read the data from a binary file/write the new data to a file, because it's over 02:00 AM over here. :)

Now I have another problem. I'm unable to sort the names+ages alphabetically. I display them correctly, but I cannot find a suitable way to sort the 2d string array and display it (just display it sorted without rearranging the array order). I searched and I found qsort(), which I couldn't get to work, I also tried using strcpy() and strcmp() also unsuccessfully.

It's really quite simple. Assuming you know how to code a bubble sort, let's say these are some fragments of your number-handling code:

Code:

---

int array[ELEMENTS];  /* declare the number array */
scanf("%d", &array[x]);  /* read in a number */
printf("%d\n", array[x]);  /* print a number */
if(array[x] > array[x+1])) {  /* compare two numbers (part of bubble sort) */
array[x] = temp;  /* assign to a number (part of swap) */
void function(int array[]) {  /* pass array to function */

---

The corresponding string-handling code would look like this:

Code:

---

char array[ELEMENTS][MAX_STRING_LENGTH];  /* declare the string array */
scanf("%s", array[x]);  /* read in a string */
printf("%s\n", array[x]);  /* print a string */
if(strcmp(array[x], array[x+1]) > 0) {  /* compare two strings (part of bubble sort) */
strcpy(array[x], temp);  /* assign to a string (part of swap) */
void function(char array[ELEMENTS][]) {  /* pass array to function */

---

I said, "assuming you know how to code a bubble sort". If you don't, have a look at some online tutorials about bubble sorts.
http://www.cprogramming.com/tutorial.../sorting1.html
http://en.wikipedia.org/wiki/Bubble_sort

Or have a look at this:

Code:

---

void sort_numbers(int array[], size_t elements) {
    size_t x = 0;
    int temp, done = 0;

    while(!done) {
        done = 1;

        for(x = 0; x + 1 < elements; x ++) {
            if(array[x] > array[x+1]) {
                /* swap array[x] and array[x+1] */
                temp = array[x];
                array[x] = array[x+1];
                array[x+1] = temp;
            }
        }
    }
}

---

You can use int instead of size_t if you want -- I just like using variables of type size_t for indexing arrays.

You mentioned qsort(). qsort() is a C library function that performs a quick sort (usually) -- much more efficient than a bubble sort, but not as efficient as a quick sort could be, because qsort() has to be generic. (Quick sort is generally regarded as one of the fastest sorting algorithms.)

I say usually because, despite its name, qsort() can use any sorting algorithm. Most implementations do use quick sort, however. Not that you, the programmer, care. As long as it gets sorted, who cares how it does it?

To use quick sort, you need to create a function that will tell qsort() if the first of two elements is less than, greater than, or equal to the second. Here's an example for numbers: http://www.cplusplus.com/reference/c...lib/qsort.html

Here's one that's a bit easier to understand:

Code:

---

int compare(const void *a, const void *b) {
    int x = *(int *)a, y = *(int *)b;
    if(x < y) return -1;
    else if(x > y) return 1;
    else return 0;  /* x == y */
}

---

For strings, you can get away with

Code:

---

int compare(const void *a, const void *b) {
    return strcmp(a, b);
}

---

because strcmp() does just what qsort is looking for.

Then you call qsort like this:

Code:

---

    int n, values[] = {1, 2, 3, 4, 5, 6};
    qsort(values, sizeof(values)/sizeof(*values), sizeof(int), compare);

---

(Instead of sizeof(values)/sizeof(*values), you could use 6, I suppose. :) )

That "compare" argument is the address of the function compare(). Never mind how it works, just put the name of your function in there. &compare and compare work equally well.

Thank you, I did it with bubble sorting, it's working fine. :)