在 Linux 下查找 Java 进程的 pid

用ps

ps允许用户使用开关为其输出定义自己的格式，并通过给定的命令选择条目。我会去：-o-C

ps -C java -o pid

从手册页：

   -C cmdlist      Select by command name
                   This selects the processes whose executable name is given in cmdlist.

   -o format       user-defined format.
                   format is a single argument in the form of a blank-separated or comma-separated list, which offers a way to specify
                   individual output columns. The recognized keywords are described in the STANDARD FORMAT SPECIFIERS section below. Headers
                   may be renamed (ps -o pid,ruser=RealUser -o comm=Command) as desired. If all column headers are empty
                   (ps -o pid= -o comm=) then the header line will not be output. Column width will increase as needed for wide headers; this
                   may be used to widen up columns such as WCHAN (ps -o pid,wchan=WIDE-WCHAN-COLUMN -o comm). Explicit width control
                   (ps opid,wchan:42,cmd) is offered too. The behavior of ps -o pid=X,comm=Y varies with personality; output may be one
                   column named "X,comm=Y" or two columns named "X" and "Y". Use multiple -o options when in doubt. Use the PS_FORMAT
                   environment variable to specify a default as desired; DefSysV and DefBSD are macros that may be used to choose the default
                   UNIX or BSD columns.

可以通过指定更多限制（即运行进程的用户等）来获得更准确的结果。查看手册页以获取更多信息和其他开关。

例：

$ sleep 10 &
[1] 12654
$ ps -C sleep -o pid
12654

使用外壳

我不知道为什么你使用脚本来运行你的代码而不直接调用，但是如果你在任何情况下使用（后台）运算符，你可以通过你的shell，用变量来抓取。.shjava&pid$!

例如：

$ sleep 5 &
[1] 12395
$ echo $!
12395

命令也是如此，将设置为最后一个后台作业的 pid。java -jar .. &$!

您可以使用 awk 来获取 pid：

ps -ef | grep MpiPageRank | awk '{print $2}'

我注意到有时会找到grep本身，以将其删除：

ps -ef | grep MpiPageRank | grep -v grep | awk '{print $2}'