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无法使用 bash 脚本终止已停止的作业

tag-icon • tag-icon linux bash scripting kill jobs
无法使用 bash 脚本终止已停止的作业 
for i in $( seq 1 $1 )
do
        kill %$i
done

我尝试用这个脚本杀死已停止的作业，但有趣的是，即使我有空缺的作业，它也无法做到这一点。

$ jobs
[10]   Stopped                 vim detect_thread.py
[11]   Stopped                 python3 detect.py
[12]-  Stopped                 python3 detect.py
[13]+  Stopped                 python3 detect.py
$ kill 13
bash: kill: (13) - No such process
$ ./delete.sh 13
./delete.sh: line 8: kill: %1: no such job
./delete.sh: line 8: kill: %2: no such job
./delete.sh: line 8: kill: %3: no such job
./delete.sh: line 8: kill: %4: no such job
./delete.sh: line 8: kill: %5: no such job
./delete.sh: line 8: kill: %6: no such job
./delete.sh: line 8: kill: %7: no such job
./delete.sh: line 8: kill: %8: no such job
./delete.sh: line 8: kill: %9: no such job
./delete.sh: line 8: kill: %10: no such job
./delete.sh: line 8: kill: %11: no such job
./delete.sh: line 8: kill: %12: no such job
./delete.sh: line 8: kill: %13: no such job

答案1

内置kill函数仅识别%N当前 shell 中运行的作业的格式。但是，shell 脚本在其自己单独的子 shell 中运行，并且在该子 shell 中，没有要终止的作业。通过一个例子可能会更清楚：

$ for i in {1..5}; do sleep 100 & done
[1] 2259152
[2] 2259153
[3] 2259154
[4] 2259155
[5] 2259156
$ for i in {1..5}; do kill %$i; done
[1]   Terminated              sleep 100
[2]   Terminated              sleep 100
[3]   Terminated              sleep 100
[4]-  Terminated              sleep 100
[5]+  Terminated              sleep 100

正如您所看到的，如果您在同一个 shell 会话中运行两组命令，那么这将按预期工作。同样，如果您从同一个 shell 脚本启动和终止命令，它也会起作用：

#! /usr/bin/env bash
for i in {1..5}; do
  sleep 100 &
done

## Show the running jobs
runningSleepJobs=$(pgrep -c sleep)
echo "There are $runningSleepJobs sleep jobs running!"

for i in {1..5}; do
  kill %$i;
done
## Show that they've been stopped
runningSleepJobs=$(pgrep -c sleep)
echo "Now there are $runningSleepJobs sleep jobs running!"

如果我现在运行此脚本，我可以看到它既启动又按预期终止作业：

$ foo.sh
There are 5 sleep jobs running!
Now there are 0 sleep jobs running!

不过，有一种方法可以解决这个问题。代替执行你的脚本，你可以获取它以便它在当前 shell 中运行：

$ cat ~/bin/foo.sh
#! /usr/bin/env bash
for i in $( seq 1 $1 )
do
        kill %$i
done

$ for i in {1..5}; do sleep 100 & done
[1] 2295221
[2] 2295222
[3] 2295223
[4] 2295224
[5] 2295225

$ jobs
[1]   Running                 sleep 100 &
[2]   Running                 sleep 100 &
[3]   Running                 sleep 100 &
[4]-  Running                 sleep 100 &
[5]+  Running                 sleep 100 &

$ . ~/scripts/foo.sh 5
[1]   Terminated              sleep 100
[2]   Terminated              sleep 100
[3]   Terminated              sleep 100
[4]-  Terminated              sleep 100
[5]+  Terminated              sleep 100

答案2

shell 脚本将在其自己的环境中运行，这意味着作业管理将不知道执行脚本的 shell 的作业名册。用于.在当前环境中运行脚本：

$ . ./delete.sh 13

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