ddy 狡兔三窟之一

use strict;
use Win32::OLE;


my $Excel = Win32::OLE->new('Excel.Application','Quit');
my $xlsfn = Win32::GetFullPathName("LANG_CHINESE.xls");
my $Book = $Excel->Workbooks->Open($xlsfn) or die "please assign file.";
my $working_sheet_1 = 1;
my $Sheet = $Book->Worksheets($working_sheet_1);


foreach my $row (2..3000)
{
    next unless defined $Sheet->Cells($row,1)->{'Value'};

    my $string_id = $Sheet->Cells($row,1)->{'Text'};
    my $eng_str = $Sheet->Cells($row,2)->{'Text'};
    my $cht_str = $Sheet->Cells($row,3)->{'Text'};
    
    #display to screen
    printf "%s  %s  %s\n",$string_id,$eng_str,$cht_str;
}

$Excel->Quit;
$Book = 0;
$Excel = 0;

1. 字串與數值轉換
2. 位元順序轉換
3. 網路位址轉換

#include <stdlib.h>
int atoi (const char *str);

#include <stdio.h>
int sprintf (char *str,const char *format,...);

#include <netinet/in.h>

uint32_t htonl(uint32_t hostlong);//32位元資料轉換
uint16_t htons(uint16_t hostshort);//16位元資料轉換
uint32_t ntohl(uint32_t netlong);
uint16_t ntohs(uint16_t netshort);

#include <netinet/in.h>
uint32_t htonl(uint32_t hostlong);

#include <netinet/in.h>
uint32_t ntohl(uint32_t netlong);

     readfp = popen("ps aux |grep in.telnetd |grep -v grep |wc -l","r");
     if (readfp !=NULL)
     {
         fgets(buffer,10,readfp);
         pclose(readfp);
         
         if (atoi(buffer)>MAXCONNECTION)
             return 0;        
     }

優點：可以熟悉telnetd 的source code
缺點：1.telnetd 與官版不一致，更新易出問題
     2.若使用ssh 則無法控管，除非也修改sshd (我真的也傻傻地改了sshd)

 #include <stdio.h>
 #include <stdlib.h>
 
 int main(int argc, char *argv[])
 {
     int *p;
     int i;
 
     #ifdef DEBUG
         setenv("MALLOC_TRACE", "./memleak.log", 1);
         mtrace();
     #endif
 
     p=(int *)malloc(1000);
     if (p!=NULL)
     {
         for (i=0;i<1000;i++)
         {
           p[i]=i;
         }
     }
     else
         printf("malloc fail");
 
     return 0;
 }

在這個程式裡malloc了一個空間，卻沒有free掉，我們為了除錯加了下面這段code
     #ifdef DEBUG
         setenv("MALLOC_TRACE", "./memleak.log", 1);
         mtrace();
     #endif

然後編譯  gcc -g -o aa -DDEBUG aa.c