[Linux] undefined reference to `itoa'

本文轉至http://blog.csdn.net/joeblackzqq/article/details/6934921

在linux寫了個簡單的C程序，裏面用到了itoa，但是編譯時提示“undefined reference to `itoa'”，本以爲加上-lc就行了，可結果還是一樣。上網發現，有人說這個函數在linux中是不存在的，一般用sprintf來代替。看下面代碼及註釋吧：

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

int num = 0;
char namebuf[100];
char prefix[] = "/tmp/tmp/p";

char* gentemp()
{
    int length, pid;

    pid = getpid();
    strcpy(namebuf, prefix);
    length = strlen(namebuf);
    //itoa(pid, &namebuf[length], 10);      // Unix版本：itoa()在頭文件<stdlib.h>中不存在
    sprintf(namebuf+length, "%d", pid);     // 使用sprintf將整數轉換成字符串
    strcat(namebuf, ".");
    length = strlen(namebuf);
    printf("before do...while\n");
    char command[1024] = {0};
    do
    {
        //itoa(num++, &namebuf[length], 10);
        sprintf(namebuf+length, "%d", num++);
        sprintf(command, "touch %s", namebuf);  // 通過touch來創建文件
        system(command);
        printf("command = %s, namebuf[%d]=%d\n", command, num-1, num-1);
    } while (num < 50 && access(namebuf, 0) != -1);  // access判斷文件是否存在
    printf("end of do...while\n");

    return namebuf;
}

int main( void )
{
    char *p = gentemp();
    printf("%s\n", p);

    return 0;
}