[Linux] undefined reference to `itoa'

本文转至http://blog.csdn.net/joeblackzqq/article/details/6934921

在linux写了个简单的C程序，里面用到了itoa，但是编译时提示“undefined reference to `itoa’”，本以为加上-lc就行了，可结果还是一样。上网发现，有人说这个函数在linux中是不存在的，一般用sprintf来代替。看下面代码及注释吧：

#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()在头文件<stdlib.h>中不存在    sprintf(namebuf+length, "%d", pid);     // 使用sprintf将整数转换成字符串    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);  // 通过touch来创建文件        system(command);        printf("command = %s, namebuf[%d]=%d\n", command, num-1, num-1);    } while (num < 50 && access(namebuf, 0) != -1); // access判断文件是否存在    printf("end of do...while\n");    return namebuf;}int main( void ){    char *p = gentemp();    printf("%s\n", p);    return 0;}