2012年3月25日 星期日

time 指令

time 指令 !


會顯示 執行的 時間 列表 !!!

ex


time /.a.out
會顯示出
4. real 0m0.136s
5. user 0m0.010s
6. sys 0m0.070s

類似這樣的結果

2012年3月20日 星期二

pid_t

http://www.delorie.com/gnu/docs/glibc/libc_566.html


26.3 Process Identification

The pid_t data type represents process IDs. You can get the process ID of a process by calling getpid. The function getppid returns the process ID of the parent of the current process (this is also known as the parent process ID). Your program should include the header files `unistd.h' and `sys/types.h' to use these functions.

Data Type: pid_t
The pid_t data type is a signed integer type which is capable of representing a process ID. In the GNU library, this is an int.


Function: pid_t getpid (void)
The getpid function returns the process ID of the current process.


Function: pid_t getppid (void)
The getppid function returns the process ID of the parent of the current process.