Where is itoa

I know it's not quite as concise or cool as itoa , but at least you can Write Once, Run Everywhere tm ;-. You are correct in stating that the default gcc libc does not include itoa , like several other platforms, due to it not technically being a part of the standard. See here for a little more info. Stefano Palazzo Rcart Rcart 11 1 1 gold badge 1 1 silver badge 2 2 bronze badges. Add a comment.

Active Oldest Votes. It doesn't appear to be defined in 4. Improve this answer. Sounds like they want to compile a software package that uses the function — Stefano Palazzo. And their suite lacks the function which one would need to compile it. So there is the function ready for linking.

Am i missing some subtle point you are trying to make? Give us a usage example. The book notes several issues with this implementation, including the fact that it does not correctly handle the most negative number.

If you are calling it a lot, the advice of "just use snprintf" can be annoying. So here's what you probably want:. Not only is itoa missing from gcc, it's not the handiest function to use since you need to feed it a buffer. I needed something that could be used in an expression so I came up with this:. Ordinarily it would be safer to use snprintf instead of sprintf but the buffer is carefully sized to be immune to overrun. As Matt J wrote, there is itoa , but it's not standard.

Your code will be more portable if you use snprintf. Following function allocates just enough memory to keep string representation of the given number and then writes the string representation into this area using standard sprintf method.

Check out how guys from MySQL did it. MySQL's implementation of int2str. I provide the mentioned implementation here; the link is here for reference and should be used to read the full implementation. When decreasing radix, increase number of characters variable i. When increasing radix, decrease number of characters better. Here is a much improved version of Archana's solution. As itoa is not standard in C, various versions with various function signatures exists.

Should it be missing from Linux or if code does not want to limit portability, code could make it own. This question asks how to roll your own: How to convert an int to string in C? It should be the fastest itoa ever. We use itoa instead of sprintf for performance reason, so a fastest itoa with limited feature is reasonable and worthwhile.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Where is the itoa function in Linux? Ask Question. Asked 13 years, 1 month ago. Active 2 years, 3 months ago. If base is 10 and value is negative, the resulting string is preceded with a minus sign -.

With any other base, value is always considered unsigned. Using repeated division by the given base, we get individual digits from least significant to most significant digit.

But in the output, these digits are needed in reverse order. Therefore, we reverse the string obtained after repeated division and return it. Otherwise numbers are considered unsigned. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.