#include
void func(int);
main(){
void (*fp)(int);
fp = func;
(*fp)(1);
fp(2);
exit(EXIT_SUCCESS);
}
void
func(int arg){
printf("%d\n", arg);
}
2/14/2010
function pointer example
#include
#include
void func(int);
main(){
void (*fp)(int);
fp = func;
(*fp)(1);
fp(2);
exit(EXIT_SUCCESS);
}
void
func(int arg){
printf("%d\n", arg);
}
#include
void func(int);
main(){
void (*fp)(int);
fp = func;
(*fp)(1);
fp(2);
exit(EXIT_SUCCESS);
}
void
func(int arg){
printf("%d\n", arg);
}
2/12/2010
illustrate a[x] means *(a+x) equals *(x+a) equals x[a]
code:
int main(void)
{
char a[4]="123";
a[2]='x';
puts(a);
2[a]='y';
puts(a);
return 0;
}
executive result:
12x
12y
2/03/2010
[Research] List the keyword
List the keyword:
o. write a sentence about your topic
o. pull out the keywords and phrases in the sentence above and list them separately.
o. start expanding the list with related terms and synonyms.
o. Are there any larger categories that might lead you to information?
o. Are there any words or phrases that are more specific?
o. now you have a beginning list of key words and phraeses to begin searching for
information.
o. Synonyms and Related Terms
o. Larger Categories
o. Smaller Categories
2/02/2010
skype codec policy
最近想要去驗證skype的一個機制, 通常如果要驗證, 就會想要自己製造出同樣的環境來模擬skype的環境, 理想上要製造出一模一樣的環境, 這樣結果當然會是最正確, 但是既然是模擬, 就不可能一模一樣, 因為一模一樣就不叫模擬了, 叫做實現.
現在問題就是, 我到底可以做到多像, 多接近skype本身的codec policy. 首先, 我要先研究skype的機制, 目前已經初步判定他可能的機制, 接下來要製造出和實驗一模一樣的設定值, 然後套用在模擬的環境中, 在各方面設定都相同的情況下, 做出的結果理論上也應該要相似.
目前所遇到的難點在於, 不是非常確定skype codec的環境設置, 如此一來, 模擬跟實驗的結果就理當會有差異了. 我們先假設skype有按照codec的標準走, 而我們的模擬也要確定有按照codec標準走, 先做到這樣, 再看看結果,
1/31/2010
some ways to recover loss packet
o. FEC (forward error correction)
o. Interleaving
o. Packet Repetition
o. Interpolation
1/28/2010
memset 問題
Function: void * memset ( void * ptr, int value, size_t num );
However, The third variable of memset is Number of bytes to be set to the value.
Still don't know the reason of this
1/17/2010
如何在codeblocks設定連結winsock library
exec codeblocks
Go to CodeBlocks Folder (normally C:\Program Files\CodeBlocks)
then MingW then libs and find libws2_32.a and add it.
1/10/2010
what is analysis exactly?
Analysis is the process of breaking a complex topic or substance into smaller parts to gain a better understanding of it.
(from wikipedia)
(from wikipedia)
1/08/2010
製作強制關機捷徑 on windows
1. 在桌面按右鍵->新增->捷徑
2. 在輸入項目的位置處 輸入 shutdown -s -t 50 -c "shutdown message"意思是系統會在50秒內強制關機
3. 按下一步完成
4. 點選剛剛新增好的捷徑測試
warning: 請先存檔尚未儲存的檔案
1/07/2010
very humorous R example code
fun <- function() {
ANSWER <- readline("Are you a satisfied R user? ")
if (substr(ANSWER, 1, 1) == "n")
cat("This is impossible. YOU LIED!\n")
else
cat("I knew it.\n")
}
fun()
1/06/2010
[LOOP] loop problem
問題:
mac address 衝突 產生 loop message - loop(1) xx.xx.xx.xx.xx.xx to ex1 from ex0. (active)
解決過程:
先看到錯誤訊息, 把訊息中ip mac 傳送的source and destination 畫出來.
發現從不同網卡傳送的封包具有相同的mac address. 結果發現ap 與我的電腦的mac address竟然一樣.
就發現當初在設定ap的時候有個功能是複製你的PC的mac address. 這個功能可能是為了方便填寫mac.
然後你自己要在修改mac address. 不知道為什麼ap 沒有自己預設的mac address而要自己設置.
1/03/2010
1/01/2010
12/31/2009
12/30/2009
[Ruby] string format
"%.3f" % (1.0/7) # "0.143"
"%5.1f" % 345.6789 # "345.7"
"%05d" % 123 # "00123"
"%-5s" % "ID" # "ID "
"%04x" % 0xfc14 # "fc14"
"%6.2f, %05d" % [345.6789,123] # "345.68, 00123"
"%-5s: %04x" % ["ID", 0xfc14] # "ID : fc14"
"%5.1f" % 345.6789 # "345.7"
"%05d" % 123 # "00123"
"%-5s" % "ID" # "ID "
"%04x" % 0xfc14 # "fc14"
"%6.2f, %05d" % [345.6789,123] # "345.68, 00123"
"%-5s: %04x" % ["ID", 0xfc14] # "ID : fc14"
12/28/2009
12/18/2009
[指令] WC - 印出文件 行數 字數 byte數
指令： wc
參數：-c, --bytes 印出位元數-m, --chars 印出字數 印出該文件有幾個字-l, --lines 印出該文件有幾行 -L, --max-line-length 印出該文件最長的那行有幾字-w, --words 印出單字數目This is just a note to prevent me forgot it. :P12/14/2009
[問題] switch 裡面放switch 時 default: 的問題
error: ‘default’ label in scope of identifier with variably modified type not containing enclosing switch statement
to be solved...
12/07/2009
解決在OS X 使用terminal遠端使用screen無法backspace的情況
In terminal program, choose preferences -> advanced;
select "Delete sends Ctrl+H"
done!
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