怎样把数当做字符串写入另外的txt文件?

#include <stdio.h> int main(void) { char line[3]; FILE* fp; line[0]=0x32; line[1]=0x33; line[2]=0x34; fp=fopen("test.txt","w+"); fwrite(line,sizeof(char),3,fp); fclose(fp); return 0; }

test.txt文件内容为123