函数名: printf 
 功  能: 产生格式化输出的函数 
 用  法: #include <stdio.h> 
         int printf(char *format...); 
 程序例: 
#include <stdio.h> 
 #include <string.h> 
#define I 555 
 #define R 5.5 
int main(void) 
 { 
    int i,j,k,l; 
    char buf[7]; 
    char *prefix = buf; 
    char tp[20]; 
    printf("prefix  6d      6o      8x        10.2e        " 
           "10.2f\n"); 
    strcpy(prefix,"%"); 
    for (i = 0; i < 2; i++) 
    { 
       for (j = 0; j < 2; j++) 
          for (k = 0; k < 2; k++) 
      for (l = 0; l < 2; l++) 
             { 
                if (i==0)  strcat(prefix,"-"); 
                if (j==0)  strcat(prefix,"+"); 
                if (k==0)  strcat(prefix,"#"); 
                if (l==0)  strcat(prefix,"0"); 
                printf("%5s |",prefix); 
                strcpy(tp,prefix); 
                strcat(tp,"6d |"); 
                printf(tp,I); 
                strcpy(tp,""); 
                strcpy(tp,prefix); 
                strcat(tp,"6o |"); 
                printf(tp,I); 
                strcpy(tp,""); 
                strcpy(tp,prefix); 
                strcat(tp,"8x |"); 
                printf(tp,I); 
                strcpy(tp,""); 
                strcpy(tp,prefix); 
         strcat(tp,"10.2e |"); 
         printf(tp,R); 
         strcpy(tp,prefix); 
         strcat(tp,"10.2f |"); 
         printf(tp,R); 
         printf("  \n"); 
         strcpy(prefix,"%"); 
      } 
        } 
    return 0; 
 }