Check running status of a background process launched from same bash script
我必须编写一个bash脚本，它根据传递的命令行参数在后台启动一个进程，并返回它是否能够成功地启动程序。
下面是我试图实现的一个伪代码
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | if ["$1" ="PROG_1" ] ; then ./launchProg1 & if [ isLaunchSuccess ] ; then echo"Success" else echo"failed" exit 1 fi elif ["$1" ="PROG_2" ] ; then ./launchProg2 & if [ isLaunchSuccess ] ; then echo"Success" else echo"failed" exit 1 fi fi |
脚本不能EDCOX1，0或EDCOX1，1，因为它将被另一个关键任务的C++程序调用，并且需要高吞吐量(每秒启动进程的WRT NOT)，而且进程的运行时间是未知的。脚本既不需要捕获任何输入/输出，也不等待启动的进程完成。
我尝试以下操作失败：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #Method 1 if ["$1" ="KP1" ] ; then echo"The Arguement is KP1" ./kp 'this is text' & if [ $? ="0" ] ; then echo"Success" else echo"failed" exit 1 fi elif ["$1" ="KP2" ] ; then echo"The Arguement is KP2" ./NoSuchCommand 'this is text' & if [ $? ="0" ] ; then echo"Success" else echo"failed" exit 1 fi #Method 2 elif ["$1" ="CD5" ] ; then echo"The Arguement is CD5" cd"doesNotExist" & PROC_ID=$! echo"PID is $PROC_ID" if kill -0"$PROC_ID" ; then echo"Success" else echo"failed" exit 1 fi #Method 3 elif ["$1" ="CD6" ] ; then echo"The Arguement is CD6" cd .. & PROC_ID=$! echo"PID is $PROC_ID" ps -eo pid | grep"$PROC_ID" && { echo"Success"; exit 0; } ps -eo pid | grep "$PROC_ID" || { echo"failed" ; exit 1; } else echo"Unknown Argument" exit 1 fi |
运行脚本会产生不可靠的输出。方法1、2总是返回
这是在
1 2 3 4 5 6 7 8 9 10 11 | [scripts]$ ./processStarted3.sh KP1 The Arguement is KP1 Success [scripts]$ ./processStarted3.sh KP2 The Arguement is KP2 Success ./processStarted3.sh: line 13: ./NoSuchCommand: No such file or directory [scripts]$ ./processStarted3.sh CD6 The Arguement is CD6 PID is 25050 failed |
正如在类似问题中所建议的，我不能使用进程名称，因为一个进程可能会执行多次，而其他进程则无法应用。
我没有尝试过screen和tmux，因为获得在生产服务器上安装它们的权限并不容易(但如果这是唯一的选择的话，我会这么做)。
更新@霍蒂
当进程完成执行或程序异常终止时，这并不重要。通过脚本启动的程序不会以任何方式进行跟踪(因此我们不在任何表中存储
@ Etan Reisner无法启动的程序示例将是不存在的
@ Vorsprung调用一个在后台启动程序的脚本不需要花费很多时间(并且可以根据我们的期望进行管理)。但随着时间的推移，
上述
下面是一个例子，它将显示一个进程是否成功启动的结果。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | #!/bin/bash $1 & #executes a program in background which is provided as an argument pid=$! #stores executed process id in pid count=$(ps -A| grep $pid |wc -l) #check whether process is still running if [[ $count -eq 0 ]] #if process is already terminated, then there can be two cases, the process executed and stop successfully or it is terminated abnormally then if wait $pid; then #checks if process executed successfully or not echo"success" else #process terminated abnormally echo"failed (returned $?)" fi else echo"success" #process is still running fi #Note: The above script will only provide a result whether process started successfully or not. If porcess starts successfully and later it terminates abnormally then this sciptwill not provide a correct result |
接受的答案并不像广告上说的那样有效。
此检查中的计数将始终至少为1，因为"grep$pid"将找到具有$pid的进程(如果存在)和grep。
1 2 3 4 5 6 7 | count=$(ps -A| grep $pid |wc -l) if [[ $count -eq 0 ]] then ### We can never get here else echo"success" #process is still running fi |
将上述内容更改为检查计数为1或从计数中排除grep，应使原始工作正常进行。
这里是原始示例的替代(可能更简单)实现。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | #!/bin/bash $1 & # executes a program in background which is provided as an argument pid=$! # stores executed process id in pid # check whether process is still running # The"[^[]" excludes the grep from finding itself in the ps output if ps | grep"$pid[^[]">/dev/null then echo"success (running)" # process is still running else # If the process is already terminated, then there are 2 cases: # 1) the process executed and stop successfully # 2) it is terminated abnormally if wait $pid # check if process executed successfully or not then echo"success (ran)" else echo"failed (returned $?)" # process terminated abnormally fi fi # Note: The above script will detect if a process started successfully or not. If process is running when we check, but later it terminates abnormally then this script will not detect this. |
使用
将以下内容放入bash脚本并执行
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | #!/bin/bash { sleep 1 ; echo sleep1 ; } & sleep 0 jobs wait echo nosleep & sleep 0 jobs wait echo exit1 false & sleep 0 jobs wait notexisting & sleep 0 jobs wait ./existingbutnotexecutable & sleep 0 jobs wait |
输出
1 2 3 4 5 6 7 8 9 10 11 | $ ./testrun.sh [1]+ Running { sleep 1; echo sleep1; } & sleep1 nosleep [1]+ Done echo nosleep exit1 [1]+ Exit 1 false ./testrun.sh: line 19: notexisting: command not found [1]+ Exit 127 notexisting ./testrun.sh: line 24: ./existingbutnotexecutable: Permission denied [1]+ Exit 126 ./existingbutnotexecutable |
从
- 仍在运行的后台作业
- 完成运行的作业
- 以非零exitstatus状态运行的作业
- 由于找不到命令而无法运行的作业
- 以及由于不可执行而无法运行的作业。
也许还有更多的案例，但我没有做更多的研究。
必须使用
卸下
1 2 3 4 5 6 7 8 9 10 11 | $ ./testrun.sh [1]+ Running { sleep 1; echo sleep1; } & sleep1 [1]+ Running echo nosleep & nosleep exit1 [1]+ Running false & [1]+ Running notexisting & ./testrun.sh: line 19: notexisting: command not found [1]+ Running ./existingbutnotexecutable & ./testrun.sh: line 24: ./existingbutnotexecutable: Permission denied |
注意，
根据
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | #!/bin/bash isrunsuccess() { case $(jobs) in *Running*) echo">>> running" ;; *Done*) echo">>> done" ;; *Exit\ 127*) echo">>> not found" ;; *Exit\ 126*) echo">>> not executable" ;; *Exit*) echo">>> done nonzero exitstatus" ;; esac } { sleep 1 ; echo sleep1 ; } & sleep 0 isrunsuccess wait echo nosleep & sleep 0 isrunsuccess wait echo exit1 false & sleep 0 isrunsuccess wait notexisting & sleep 0 isrunsuccess wait ./existingbutnotexecutable & sleep 0 isrunsuccess wait |
输出
1 2 3 4 5 6 7 8 9 10 11 | $ ./testrun.sh >>> running sleep1 nosleep >>> done exit1 >>> done nonzero exitstatus ./testrun.sh: line 29: notexisting: command not found >>> not found ./testrun.sh: line 34: ./existingbutnotexecutable: Permission denied >>> not executable |
您可以合并"已运行"和"未运行"案例
1 2 3 4 5 6 | isrunsuccess() { case $(jobs) in *Exit\ 127*|*Exit\ 126*) echo">>> did not run" ;; *Running*|*Done*|*Exit*) echo">>> still running or was running" ;; esac } |
输出
1 2 3 4 5 6 7 8 9 10 11 | $ ./testrun.sh >>> still running or was running sleep1 nosleep >>> still running or was running exit1 >>> still running or was running ./testrun.sh: line 26: notexisting: command not found >>> did not run ./testrun.sh: line 31: ./existingbutnotexecutable: Permission denied >>> did not run |
检查bash中字符串内容的其他方法：如何在UnixShell脚本中判断一个字符串是否包含另一个字符串？
bash说明exit status 127 for not found和126 for not executable的文档：https://www.gnu.org/software/bash/manual/html_node/exit-status.html
抱歉，错过了这个要求"脚本不能等待或休眠"
启动后台程序，获取PID。等一下。然后检查它是否仍在运行kill-0
杀戮-0状态从$获取？这用于决定进程是否仍在运行
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | #!/bin/bash ./$1 & pid=$! sleep 1; kill -0 $pid stat=$? if [ $stat -eq 0 ] ; then echo"running as $!" exit 0 else echo"$! did not start" exit 1 fi |
也许如果你的超级C++程序不能等待一秒钟，它也不能期望能够以每秒高的速率启动shell命令的加载。
也许你需要在这里实现一个队列？
对不起，我的问题比答案还多