用Linux看护进程检测某个程序是否运行2

用Linux守护进程检测某个程序是否运行2

用Linux守护进程检测某个程序是否运行2

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本文博客链接:http://blog.csdn.net/jdh99,作者:jdh,转载请注明.

环境：

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主机:Fedora12

目标板：SC6410

目标板LINUX内核版本：2.6.36

说明：

第一版程序（参考http://blog.csdn.net/jdh99/article/details/7300641）已经可以正常工作，不过在运行一个月后发现有两台平板出现不能启动的问题，检查后发现是nand flash坏块很多，导致系统不能启动。究其原因，因该是对flash频繁的写操作造成的。上一版本的守护程序每分钟会写操作一次，这样一天的写操作就达千次。在这一版本中，判断需要守护的进程是否存在，是通过读取/proc/pid目录来判断的。参考链接：http://kb.cnblogs.com/a/2360817/

驱动源代码：

daemon_service.c:

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1. //守护进程，守护AlarmInterface进程??
2. //作者：jdh??
3. //时间：2012-2-27??
4. #include?<stdio.h>??
5. #include?<unistd.h>??
6. #include?<sys/types.h>??
7. #include?<sys/stat.h>??
8. #include?<fcntl.h>??
9. #include?<syslog.h>??
10. #include?<dirent.h>??
11. ??
12. //程序名字??
13. #define?NAME?"AlarmInterface"??
14. //要运行的程序??
15. #define?RUN_NAME?"DuiJiang?&"??
16. ??
17. #define?READ_BUF_SIZE?100??
18. ??
19. //#define?DIR_OUT_FILE?"/rf/out"??
20. //#define?NAME?"gnome-keyring"??
21. //#define?NAME_FIND?"gnome"??
22. //#define?DIR_OUT_FILE?"/root/test/out"??
23. ??
24. int?daemon(int?nochdir,int?noclose)??
25. {??
26. ????pid_t?pid;??
27. ??
28. ????//让init进程成为新产生进程的父进程??
29. ????pid?=?fork();??
30. ????//如果创建进程失败??
31. ????if?(pid?<?0)??
32. ????{??
33. ????????perror("fork");??
34. ????????return?-1;??
35. ????}??
36. ????//父进程退出运行??
37. ????if?(pid?!=?0)??
38. ????{??
39. ????????exit(0);??
40. ????}??
41. ????//创建新的会话??
42. ????pid?=?setsid();??
43. ????if?(pid?<?-1)??
44. ????{??
45. ????????perror("set?sid");??
46. ????????return?-1;??
47. ????}??
48. ????//更改当前工作目录,将工作目录修改成根目录??
49. ????if?(!nochdir)??
50. ????{??
51. ????????chdir("/");??
52. ????}??
53. ????//关闭文件描述符，并重定向标准输入，输出合错误输出??
54. ????//将标准输入输出重定向到空设备??
55. ????if?(!noclose)??
56. ????{??
57. ????????int?fd;??
58. ????????fd?=?open("/dev/null",O_RDWR,0);??
59. ????????if?(fd?!=?-1)??
60. ????????{??
61. ????????????dup2(fd,STDIN_FILENO);??
62. ????????????dup2(fd,STDOUT_FILENO);??
63. ????????????dup2(fd,STDERR_FILENO);??
64. ????????????if?(fd?>?2)??
65. ????????????{??
66. ????????????????close(fd);??
67. ????????????}??
68. ????????}??
69. ????}??
70. ????//设置守护进程的文件权限创建掩码??
71. ????umask(0027);??
72. ??
73. ????return?0;??
74. }??
75. ??
76. //存在返回1，不存在返回0??
77. int?judge_pid_exist(char*?pidName)??
78. {??
79. ????DIR?*dir;??
80. ????????struct?dirent?*next;??
81. ????????//long*?pidList=NULL;??
82. ????????int?i=0;??
83. ??
84. ????FILE?*status;??
85. ??????char?filename[READ_BUF_SIZE];??
86. ??????char?buffer[READ_BUF_SIZE];??
87. ??????char?name[READ_BUF_SIZE];??
88. ???
89. ??????///proc中包括当前的进程信息,读取该目录??
90. ????????dir?=?opendir("/proc");??
91. ????????if?(!dir)??
92. ????{??
93. ????????printf("Cannot?open?/proc\n");??
94. ????????return?0;??
95. ????}??
96. ???????
97. ????????//遍历??
98. ????????while?((next?=?readdir(dir))?!=?NULL)???
99. ????{??
100. ????????????/*?Must?skip?".."?since?that?is?outside?/proc?*/??
101. ????????????if?(strcmp(next->d_name,?"..")?==?0)??
102. ????????{??
103. ????????????????continue;??
104. ????????}??
105. ???
106. ????????????/*?If?it?isn't?a?number,?we?don't?want?it?*/??
107. ????????????if?(!isdigit(*next->d_name))??
108. ????????{??
109. ????????????????continue;??
110. ????????}??
111. ??
112. ????????????????//设置进程??
113. ????????????sprintf(filename,?"/proc/%s/status",?next->d_name);??
114. ????????????if?(!?(status?=?fopen(filename,?"r"))?)???
115. ????????{??
116. ????????????????continue;??
117. ????????????}??
118. ??
119. ????????????if?(fgets(buffer,?READ_BUF_SIZE-1,?status)?==?NULL)???
120. ????????{??
121. ????????????????fclose(status);??
122. ????????????????continue;??
123. ????????????}??
124. ????????????fclose(status);??
125. ???
126. ????????????????//得到进程id??
127. ????????????/*?Buffer?should?contain?a?string?like?"Name:???binary_name"?*/??
128. ????????????sscanf(buffer,?"%*s?%s",?name);??
129. ????????????if?(strcmp(name,?pidName)?==?0)???
130. ????????{??
131. ????????????????//pidList=realloc(?pidList,?sizeof(long)?*?(i+2));??
132. ????????????????//pidList[i++]=strtol(next->d_name,?NULL,?0);??
133. ??
134. ????????????//printf("hello,%s\n",next->d_name);??
135. ??
136. ????????????return?1;??
137. ????????????}??
138. ????????}??
139. ???
140. ????????//if?(pidList)???
141. ????//{??
142. ????????????//pidList[i]=0;??
143. ????????//}??
144. ????????return?0;??
145. }??
146. ??
147. int?main(int?argc,char?*argv[])??
148. {??
149. ????int?fd?=?0;??
150. ????char?buf[100];??
151. ??
152. ????//开启守护进程??
153. ????daemon(0,0);??
154. ??
155. ????while?(1)??
156. ????{??
157. ????????//打开日志??
158. ????????//openlog(argv[0],LOG_CONS|LOG_PID,LOG_USER);??
159. ??????????
160. ????????//判断是否有程序文件运行??
161. ????????if?(judge_pid_exist(NAME))??
162. ????????{??
163. ????????????//syslog(LOG_INFO,"jdh?success!!!!!!!!!!");??
164. ????????????//printf("hello,jdh,exist\n");????
165. ????????}??
166. ????????else??
167. ????????{??
168. ????????????//syslog(LOG_INFO,"jdh?fail!!!!!!!!!!");??
169. ????????????//运行程序??
170. ????????????system(RUN_NAME);??
171. ????????????//printf("hello,jdh,oh,no\n");??
172. ????????}??
173. ??????????
174. ????????//休眠??
175. ????????sleep(60);??
176. ????}??
177. ??
178. ????//关闭日志??
179. ????//closelog();??
180. ??
181. ????return?0;??
182. }??