I wrote a c program in linux :

1. #include <math.h>
2. {
3. for(I=0;I<=l;I++)
4. k=k+((int) str[m-I]-48)*(int) pow(10,I);
5. Why this error occured?
6. but when compile with gcc promt me:
7. }
8. you may need to compile with the -lm compiler directive….

   so compile like this

   gcc source.c -lm

9. :undefined refrence to 'pow'
10. int m,I,,k=0;
11. I prefer the method below for converting strings to ints in C++,
    what I can see from your code is an un-declared array (char str[]) and from my research it looks like your missing the following header file: #include <sstream>

    my way:
    #include <sstream>
    #include <string>
    using namespace std;

    // string to int
    string some_string;
    istringstream buffer(some_string);
    int some_int;
    buffer >> some_int;

    // int to string
    int some_int;
    ostringstream buffer;
    buffer << some_int;
    string some_string = buffer.str();

12. return(k);
13. /tmp/cciDKLpD.o(.txt+0×57): In function 'str2int' :
14. int str2int(char str[])
15. #include <string.h>
16. collected2: ld returned 1 exit status.
17. m=strlen(str)-1;

Tags: linux programming, embedded linux