C code int to string not working

Question

Here is my code which uses itoa() function , seems not working. Let me make it clear, I am working on C.

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

void main()
{       
    int i,j;
    for(i = 0;i<= 4; i++)
    {
        for (j = 0; j <= 9; j++)
        {
            //printf("Hi\n");
            char fileName[10]="A";
            char append[2];

            itoa(i,append,10);
            strcat(fileName,append);    

            itoa(j,append,10);
            strcat(fileName,append);

            printf("i=%d j=%d\n", i,j);
            printf("%s\n", fileName);
            //FMS()             
        }
        //printf("Anuj=%d\n",i );
    }
}

Output

RC4Attack.c:(.text+0x5e): undefined reference to itoa' RC4Attack.c:(.text+0x8e): undefined reference toitoa' collect2: error: ld returned 1 exit status

"Let me make it clear, I am working on C" Then why did you tag C++? — Neil Kirk, Apr 02 '14 at 20:22
[**Reference Page**](http://www.cplusplus.com/reference/cstdlib/itoa/) *"This function is **not** defined in ANSI-C and is **not** part of C++, but is supported by some compilers."* — abelenky, Apr 02 '14 at 20:23
Which compiler/platform are you using? Do you have evidence that it has an `itoa` function? How did you **link** your code? — abelenky, Apr 02 '14 at 20:24
But atoi() is working it means it should be supported. Isn't it? — Pratik K. Shah, Apr 02 '14 at 20:25
It isn't. There is an `exit` in `stdlib` but no `ixet`. Use `sprintf`, or, if you are feeling insecure, `snprintf`. — Jongware, Apr 02 '14 at 20:26
http://stackoverflow.com/questions/190229/where-is-the-itoa-function-in-linux — abelenky, Apr 02 '14 at 20:28
Tip: Why not write directly into the result buffer? Double-buffering is only useful for graphics output... — Deduplicator, Apr 02 '14 at 20:30

score 1 · Answer 1 · answered Apr 02 '14 at 20:25

1

There's no itoa in standard C library. Instead, use sprintf.

sprintf(string_value, "%d", integer_value);

EDIT Use snprintf to guard against buffer overflow as well.

snprintf(string_value, max_size, "%d", integer_value);

answered Apr 02 '14 at 20:25

avmohan

1,820
3
20
39

evenro · Answer 2 · 2014-04-02T20:34:49.120

0

I had a similar issue two weeks ago,
I solved it by using sprtinf instead of itoa.

http://www.cplusplus.com/reference/cstdio/sprintf/

Did it look like this?

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

void main()
{  
int i,j;
for(i = 0;i<= 4; i++)
{
    for (j = 0; j <= 9; j++)
    {
        //printf("Hi\n");
        char fileName[10]="A";
        char append[2];

        sprintf(filename,"%s%d",fileName,i);    
        sprintf(filename,"%s%d",fileName,j);    

        printf("i=%d j=%d\n", i,j);
        printf("%s\n", fileName);
    }
}
}

edited Apr 02 '14 at 20:34

answered Apr 02 '14 at 20:27

evenro

2,626
20
35

I tried sprint, which changed my looping somehow infinite. Its below code: #include #include #include int main() { int i,j; for(i = 0;i<= 4; i++) { for (j = 0; j <= 9; j++) { //printf("Hi\n"); char fileName[10]="A"; char append[1]; sprintf(append, "%d", i); strcat(fileName,append); sprintf(append, "%d", j); strcat(fileName,append); printf("i=%d j=%d\n", i,j); printf("%s\n", fileName); //FMS() } //printf("Anuj=%d\n",i ); } } – Pratik K. Shah Apr 02 '14 at 20:28

score 0 · Answer 3 · edited May 23 '17 at 10:31

I can offer you 2 solutions:

1.) You could try to use a different c-compiler, some may work

2.) You could write this function easily yourself. Its only a small piece of code (see the following link) http://en.wikibooks.org/wiki/C_Programming/C_Reference/stdlib.h/itoa

Also you could use a former thread about this topic which may help in your case: Where is the itoa function in Linux?

Greetings Marius

C code int to string not working

Output

3 Answers3