how to make 00008 to become 8? in C language for Raspberry pi

[Sherry123]

how to make 00008 to become 8? in C language for Raspberry pi

[scotty101]

Is 00008 currently a string?

Do you have an example of how this value is currently defined?

Something like below would work

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#include <stdio.h>

void main(void)
{
    char myString[] = "00008";
    int number;

    number = atoi(myString);
    printf("Hello World! %i\n", number);
}

[jamesh]

Without a bit more information, not possible to answer.

Presumably, 000008 is a string, but do you want to convert to a single character string "8", a single character '8', or an actual number e.g. `int num = 8`, or perhaps `double num = 8`?

[n67]

Well, as a starting point, the obvious answer is:

atoi()

[PeterO]

Just for completeness ...

No one has noted that 00008 is in fact not a valid number in C.

PeterO

[DougieLawson]

Just for completeness ...

No one has noted that 00008 is in fact not a valid number in C.

PeterO

I did. It has a leading zero so is octal and an eight isn't a valid octal digit.

[jahboater]

Did you know that 0 is an octal literal?

[PeterO]

Well, as a starting point, the obvious answer is:

atoi()

atoi() is only the right answer if the string is guaranteed to hold a valid non-zero number.
In general strtol() is better choice as failure to convert the string to a number can be detected.

PeterO

[jahboater]

atoi() is only the right answer if the string is guaranteed to hold a valid non-zero number.
In general strtol() is better choice as failure to convert the string to a number can be detected.

and you can explicitly force the base to be 10.

[PeterO]

and you can explicitly force the base to be 10.

More interestingly you can set it to bases other than 10

In the OP's case it does look like explicitly setting the base to 10 (and not relying on the default 0) is needed otherwise the string "0000008" will fail when it tries to convert from octal due to the leading zero.
PeterO

[jahboater]

Exactly.

which to be fair is what atoi() does (from the man page):

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       The behavior is the same as

           strtol(nptr, NULL, 10);

       except that atoi() does not detect errors.

but like you, I am uncomfortable with the last line!