lzy/Linux-C-Notes
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

进程的消亡及释放资源

Browse Source
This commit is contained in:
lzy
2024-05-14 07:39:34 +08:00
parent e1c6873368
commit 7d08b75eaa
10 changed files with 540 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
C13-Linux系统编程/process_basic/ex.c Normal file
View File

@@ -0,0 +1,28 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/**
* @brief data +%s
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
puts("Begin!");
fflush(NULL); // !!!
execl("/bin/date", "date", "+%s", NULL);
// NULL 作为参数列表的结束标志
// !! 如果不出错，不会到这里
perror("execl()");
exit(1);
puts("End!");
exit(0);
}

42
C13-Linux系统编程/process_basic/few.c Normal file
View File

@@ -0,0 +1,42 @@
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
/**
* @brief few: folk, execl, wait
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
pid_t pid;
puts("Begin!");
fflush(NULL);
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1);
}
if (0 == pid) // child
{
execl("/bin/date", "date", "+%s", NULL);
perror("execl()");
exit(1);
}
wait(NULL);
puts("End!");
exit(0);
}

40
C13-Linux系统编程/process_basic/fork1.c Normal file
View File

@@ -0,0 +1,40 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main(int argc, char **argv)
{
pid_t pid;
/*
* 如果 ./fork1 > /tmp/out
* begin会由父进程输出两次
* 缓冲问题
* 文件时全缓冲
*/
printf("[%d]Begin!\n", getpid());
fflush(NULL); // !!! 在fork之前刷新该刷新的流
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1);
}
if (pid == 0) // child
{
printf("[%d]Child is working!\n", getpid());
}
else // parent
{
printf("[%d]Parent is working!\n", getpid());
}
printf("[%d]End!\n", getpid());
// getchar();
exit(0);
}

41
C13-Linux系统编程/process_basic/myshell.c Normal file
View File

@@ -0,0 +1,41 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main(int argc, char **argv)
{
while (1)
{
prompt();
getline();
parse();
if (内部命令)
{
;
}
else // 外部命令
{
fork();
if (< 0)
{
;
}
if (0 ==) // child
{
execXX;
perror();
exit(1);
}
else // parent
{
wait();
}
}
}
exit(0);
}

37
C13-Linux系统编程/process_basic/primer0.c Normal file
View File

@@ -0,0 +1,37 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define LEFT 30000000
#define RIGHT 30000200
/**
* @brief 求质数（单机版）
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
int i, j, mark;
for (i = LEFT; i <= RIGHT; i++)
{
mark = 1;
for (j = 2; j < i / 2; j++)
{
if (i % j == 0)
{
mark = 0;
break;
}
}
if (mark)
printf("%d is a primer\n", i);
}
exit(0);
}

53
C13-Linux系统编程/process_basic/primer1.c Normal file
View File

@@ -0,0 +1,53 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define LEFT 30000000
#define RIGHT 30000200
/**
* @brief 求质数（多进程版）
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
int i, j, mark;
pid_t pid;
for (i = LEFT; i <= RIGHT; i++)
{
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1);
}
if (pid == 0) // child
{
mark = 1;
for (j = 2; j < i / 2; j++)
{
if (i % j == 0)
{
mark = 0;
break;
}
}
if (mark)
printf("%d is a primer\n", i);
sleep(1000); // * 让父进程先结束
exit(0); // ! 退出子进程
// ! init 在孤儿进程 exit 后才收尸
}
}
// sleep(1000); // * 让子进程先结束，子进程会变成僵尸态
exit(0);
}

56
C13-Linux系统编程/process_basic/primer2.c Normal file
View File

@@ -0,0 +1,56 @@
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
#define LEFT 30000000
#define RIGHT 30000200
/**
* @brief 求质数（多进程版）
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
int i, j, mark;
pid_t pid;
for (i = LEFT; i <= RIGHT; i++)
{
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1);
}
if (pid == 0) // child
{
mark = 1;
for (j = 2; j < i / 2; j++)
{
if (i % j == 0)
{
mark = 0;
break;
}
}
if (mark)
printf("%d is a primer\n", i);
exit(0); // ! 退出子进程
}
}
// int st;
for (i = LEFT; i <= RIGHT; i++)
// wait(&st);
wait(NULL);
exit(0);
}

59
C13-Linux系统编程/process_basic/primerN.c Normal file
View File

@@ -0,0 +1,59 @@
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
#define LEFT 30000000
#define RIGHT 30000200
#define N 3
/**
* @brief 求质数（多进程版）
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
int i, j, n, mark;
pid_t pid;
for (n = 0; n < N; n++)
{
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1); // ! 加入在第三次fork失败时，退出，前两次没有收尸
}
if (pid == 0)
{
for (i = LEFT + n; i <= RIGHT; i += N)
{
mark = 1;
for (j = 2; j < i / 2; j++)
{
if (i % j == 0)
{
mark = 0;
break;
}
}
if (mark)
printf("[%d]%d is a primer\n", n, i);
}
exit(0); // ! 退出子进程
}
}
for (n = 0; n < N; n++)
wait(NULL);
exit(0);
}

45
C13-Linux系统编程/process_basic/sleep.c Normal file
View File

@@ -0,0 +1,45 @@
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
/**
* @brief few: folk, execl, wait
* @details
*
* @param argc
* @param argv
* @return int
*/
int main(int argc, char **argv)
{
pid_t pid;
puts("Begin!");
fflush(NULL);
pid = fork();
if (pid < 0)
{
perror("fork()");
exit(1);
}
if (0 == pid) // child
{
// execl("/bin/sleep", "sleep", "100", NULL);
execl("/bin/sleep", "httpd", "100", NULL);
// ! 低级木马：进程树里看到的是httpd 100
perror("execl()");
exit(1);
}
wait(NULL);
puts("End!");
exit(0);
}