Linux下C-C++查找某一进程

1、Linux下C/C+查找某一进程一、前言：要在程序中启动某一程序，如果程序已经存在了，就不再启动。查找了N篇文档，有所收获，总结一下。二、实现大体分两种：1、exec或popen执行ps的命令行，然后运用某几个字符串匹配函数。#include#include#include#includeintmain()FILE*pstr;charcmd128,buff512,*p;pid_tpID;intpidnum;char*name=ping;/要查找的进程名intret=3;memset(cmd,0,sizeof(cmd);sprintf(cmd,ps-ef|grep%s,name);pstr=po

2、pen(cmd,r);/if(pstr=NULL)return1;memset(buff,0,sizeof(buff);fgets(buff,512,pstr);p=strtok(buff,);p=strtok(NULL,);这句是否去掉，取决于当前系统中ps后，进程ID号是否是第一个字段pclose(pstr);if(p=NULL)return1;if(strlen(p)=0)return1;if(pidnum=atoi(p)=0)return1;printf(pidnum:%dn,pidnum);pID=(pid_t)pidnum;ret=kill(pID,0);/这里不是要杀死进程，而是

3、验证一下进程是否真的存在，返回0表示真的存在printf(ret=%dn,ret);if(0=ret)printf(process:%sexist!n,name);elseprintf(process:%snotexist!n,name);return0;2、读取/proc文件找到个代码如下：读取/proc文件查找进程#ifndef_cplusplus/识别C/C+的宏，望文生义#define_GNU_SOURCE#endif#include#include#include/foropendir(),readdir(),closedir()#include/forstat()#ifdef_cp

4、lusplus#include#include#include#include#else#include#include#include#include#endif#definePROC_DIRECTORY/proc/TOC o 1-5 h z#defineCASE_SENSITIVE1#defineCASE_INSENSITIVE0#defineEXACT_MATCH1#defineINEXACT_MATCH0/是不是数字intIsNumeric(constchar*ccharptr_CharacterList)for(;*ccharptr_CharacterList;ccharptr_Ch

5、aracterList+)if(*ccharptr_CharacterList9)return0;/falsereturn1;/true/intCaseSensitive=0大小写不敏感intstrcmp_Wrapper(constchar*s1,constchar*s2,intintCaseSensitive)if(intCaseSensitive)return!strcmp(s1,s2);elsereturn!strcasecmp(s1,s2);/intCaseSensitive=0大小写不敏感intstrstr_Wrapper(constchar*haystack,constchar*n

6、eedle,intintCaseSensitive)if(intCaseSensitive)return(int)strstr(haystack,needle);elsereturn(int)strcasestr(haystack,needle);#ifdef_cpluspluspid_tGetPIDbyName(constchar*cchrptr_ProcessName,intintCaseSensitiveness,intintExactMatch)#elsepid_tGetPIDbyName_implements(constchar*cchrptr_ProcessName,intintC

7、aseSensitiveness,intintExactMatch)#endifcharchrarry_CommandLinePath100;charchrarry_NameOfProcess300;char*chrptr_StringToCompare=NULL;pid_tpid_ProcessIdentifier=(pid_t)-1;structdirent*de_DirEntity=NULL;DIR*dir_proc=NULL;int(*CompareFunction)(constchar*,constchar*,int);if(intExactMatch)CompareFunction

8、=&strcmp_Wrapper;elseCompareFunction=&strstr_Wrapper;dir_proc=opendir(PROC_DIRECTORY);if(dir_proc=NULL)perror(CouldntopenthePROC_DIRECTORYdirectory);return(pid_t)-2;/LoopwhilenotNULLwhile(de_DirEntity=readdir(dir_proc)if(de_DirEntity-d_type=DT_DIR)if(IsNumeric(de_DirEntity-d_name)strcpy(chrarry_Comm

9、andLinePath,PROC_DIRECTORY);strcat(chrarry_CommandLinePath,de_DirEntity-d_name);strcat(chrarry_CommandLinePath,/cmdline);FILE*fd_CmdLineFile=fopen(chrarry_CommandLinePath,rt);/openthefileforreadingtextif(fd_CmdLineFile)fscanf(fd_CmdLineFile,%s,chrarry_NameOfProcess);/readfrom/proc/cmdlinefclose(fd_C

10、mdLineFile);/closethefilepriortoexitingtheroutineif(strrchr(chrarry_NameOfProcess,/)chrptr_StringToCompare=strrchr(chrarry_NameOfProcess,/)+1;elsechrptr_StringToCompare=chrarry_NameOfProcess;/printf(Processname:%sn,chrarry_NameOfProcess);这个是全路径，比如/bin/ls/printf(PureProcessname:%sn,chrptr_StringToCom

11、pare);这个是纯进程名，比如ls这里可以比较全路径名，设置为chrarry_NameOfProcess即可if(CompareFunction(chrptr_StringToCompare,cchrptr_ProcessName,intCaseSensitiveness)pid_ProcessIdentifier=(pid_t)atoi(de_DirEntity-d_name);closedir(dir_proc);returnpid_ProcessIdentifier;closedir(dir_proc);returnpid_ProcessIdentifier;#ifdef_cplusp

12、luspid_tGetPIDbyName(constchar*cchrptr_ProcessName)returnGetPIDbyName(cchrptr_ProcessName,CASE_INSENSITIVE,EXACT_MATCH);#else/Ccannotoverloadfunctions-fixed/*这里是原文的实现，但貌似需要某些牛X的设置，因不需要，删之pid_tGetPIDbyName_Wrapper(constchar*cchrptr_ProcessName,.)intintTempArgument;intintInputArguments2;/intInputArgum

13、ents0=0;/intInputArguments1=0;memset(intInputArguments,0,sizeof(intInputArguments);intintInputIndex;va_listargptr;va_start(argptr,cchrptr_ProcessName);for(intInputIndex=0;(intTempArgument=va_arg(argptr,int)!=15;+intInputIndex)intInputArgumentsintInputIndex=intTempArgument;va_end(argptr);returnGetPID

14、byName_implements(cchrptr_ProcessName,intInputArguments0,intInputArguments1);#defineGetPIDbyName(ProcessName,.)GetPIDbyName_Wrapper(ProcessName,#_VA_ARGS_,(int)15)*/简单实现pid_tGetPIDbyName_Wrapper(constchar*cchrptr_ProcessName)returnGetPIDbyName_implements(cchrptr_ProcessName,0,0);/大小写不敏感#endifintmain

15、()pid_tpid=GetPIDbyName_Wrapper(bash);/If-1=notfound,if-2=procfsaccesserrorprintf(PID%dn,pid);returnEXIT_SUCCESS;通过比较全路径，能一定程度上避免第1种方法的问题。以下是整理后的C语言实现：#include#include#include/foropendir(),readdir(),closedir()#include/forstat()#include#include#include#include#definePROC_DIRECTORY/proc/#defineCASE_SE

16、NSITIVE1#defineCASE_INSENSITIVE0#defineEXACT_MATCH1#defineINEXACT_MATCH0/是不是数字intIsNumeric(constchar*ccharptr_CharacterList)for(;*ccharptr_CharacterList;ccharptr_CharacterList+)if(*ccharptr_CharacterList9)return0;/falsereturn1;/true/intCaseSensitive=0大小写不敏感intstrcmp_Wrapper(constchar*s1,constchar*s2

17、,intintCaseSensitive)if(intCaseSensitive)return!strcmp(s1,s2);elsereturn!strcasecmp(s1,s2);/intCaseSensitive=0大小写不敏感intstrstr_Wrapper(constchar*haystack,constchar*needle,intintCaseSensitive)if(intCaseSensitive)return(int)strstr(haystack,needle);elsereturn(int)strcasestr(haystack,needle);pid_tGetPIDb

18、yName_implements(constchar*cchrptr_ProcessName,intintCaseSensitiveness,intintExactMatch)charchrarry_CommandLinePath100;charchrarry_NameOfProcess300;char*chrptr_StringToCompare=NULL;pid_tpid_ProcessIdentifier=(pid_t)-1;structdirent*de_DirEntity=NULL;DIR*dir_proc=NULL;int(*CompareFunction)(constchar*,

19、constchar*,int);if(intExactMatch)CompareFunction=&strcmp_Wrapper;elseCompareFunction=&strstr_Wrapper;dir_proc=opendir(PROC_DIRECTORY);if(dir_proc=NULL)perror(CouldntopenthePROC_DIRECTORYdirectory);return(pid_t)-2;/LoopwhilenotNULLwhile(de_DirEntity=readdir(dir_proc)if(de_DirEntity-d_type=DT_DIR)if(I

20、sNumeric(de_DirEntity-d_name)strcpy(chrarry_CommandLinePath,PROC_DIRECTORY);strcat(chrarry_CommandLinePath,de_DirEntity-d_name);strcat(chrarry_CommandLinePath,/cmdline);FILE*fd_CmdLineFile=fopen(chrarry_CommandLinePath,rt);/openthefileforreadingtextif(fd_CmdLineFile)fscanf(fd_CmdLineFile,%s,chrarry_NameOfProcess);/readfrom/proc/cmdlinefclose(fd_CmdLineFile);/closethefilepriortoexitingtheroutineif(strrchr(chrarry_NameOfProcess,/)chrptr_StringToCompare=strrchr(chrarry_NameOfProcess,/)+1;elsechrptr_StringToC