C Process Learning Log

　　

#include <unistd.h>#include<sys/types.h>#include<pwd.h>#include<stdio.h>intMainintargcChar**argv)    {pid_t my_pid,parent_pid;    pid_t te; My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid is [%d]\n", My_pid,parent_pid); Te=Fork (); printf ("*********begin*************\n"); My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid are [%d]\t te is%d\n", My_pid,parent_pid,te); printf ("*********end*************\n");#if0te=Fork (); My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid are [%d]\t te is%d\n", My_pid,parent_pid,te); GetChar ();#endif

RESULT:

Mypid is [1705] parentid is [1521]
begin*************
Mypid is [1705] parentid are [1521] Te is 1706
end*************
[Email protected]:/usr/lsrcc/tempuserfun# *********begin*************
Mypid is [1706] ParentID are [1] te is 0
end*************

Result Analysis: Call fork once, fork return 2 times, one is parent process, one is child process.

#include <unistd.h>#include<sys/types.h>#include<pwd.h>#include<stdio.h>intMainintargcChar**argv)    {pid_t my_pid,parent_pid;    pid_t te; My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid is [%d]\n", My_pid,parent_pid); Te=Fork (); printf ("*********begin*************\n"); My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid are [%d]\t te is%d\n", My_pid,parent_pid,te); printf ("*********end*************\n");#if1printf ("*********2thbegin*************\n"); Te=Fork (); My_pid=Getpid (); Parent_pid=Getppid (); printf ("Mypid is [%d]\t parentid are [%d]\t te is%d\n", My_pid,parent_pid,te); printf ("********2th*end*************\n"); GetChar ();#endif}

RESULT:

begin*************
Mypid is [1801] parentid are [1521] Te is 1802
end*************//First Fork Parent process
2thbegin*************
Mypid is [1801] ParentID was [1521] Te is 1803//the 2nd fork of the parent process (based on the parent process of the first fork)
2th*end*************
Mypid is [1803] ParentID was [1801] Te is 0//the 2nd fork of the child process (based on the parent process of the first fork)
2th*end*************
begin*************
Mypid is [1802] parentid are [1801] te is 0
end*************//Sub-process for the 1th time Fork
2thbegin*************
Mypid is [1802] ParentID was [1801] Te is 1804//the 2nd fork of the parent process (based on the parent process of the 2nd fork)
2th*end*************
Mypid is [1804] ParentID was [1802] Te is 0//child process of the 2nd fork (based on the parent process of the 2nd fork)
2th*end*************

There are 6 processes at the end of the system run.

#include <unistd.h>#include<sys/types.h>#include<pwd.h>#include<stdio.h>intMainintargcChar**argv)    {pid_t my_pid,parent_pid;    pid_t te; Static intCount =0; My_pid=Getpid (); Parent_pid=Getppid (); inti =0; Const Char*p ="/usr/lsrcc/dmf/main";  for(i =0; I <2;++i) {te=Fork (); if(Te <0) {printf ("Fork err!\n"); return-1; }        if(Te >0) {printf ("I am%i \nmypid is [%d]\t parentid are [%d]\t te is%d\n", I,my_pid,parent_pid,te); printf ("This is parent\n"); Count++; }        Else if(0==te) {printf ("i is%i\nmypid are [%d]\t ParentID is] [%d]\t te is%d\n", I,my_pid,parent_pid,te); printf ("This is child\n"); Count++;        EXECLP (P,null); }} printf ("Count is%d\n", count);}

RESULT:

I is 0
Mypid is [2798] parentid are [2361] te is 2799
This is PARENT
I is 1
Mypid is [2798] parentid are [2361] te is 2800
This is PARENT
Count is 2
[Email protected]:/usr/lsrcc/tempuserfun# i is 1
I is 0
Mypid is [2798] parentid are [2361] te is 0
This is a child
This is mytool1 print Hello
Mypid is [2798] parentid are [2361] te is 0
This is a child
This is mytool1 print Hello
This is mytool2 print Hello
This is mytool2 print Hello

An example of a child process invocation is provided primarily

C Process Learning log