Linux命令jobs小记

命令使用过程中，输出中总是会带两个符号：+ 和 -，如：

[1]   7893 Running                 gpass &
[2]   7904 Running                 gnome-calculator &
[3]-  7955 Running                 gedit fetch-stock-prices.py &
[4]+  7958 Stopped                 ping cyberciti.biz

它们的含义如下：

%Number  : Use the job number such as %1 or %2.
%String  : Use the string whose name begins
                  with suspended command such as %commandNameHere or
                  %ping.
%+ OR %% : Refers to the current job.
%-       : Refers to the previous job.

具体可参见：https://www.geeksforgeeks.org/process-control-commands-unixlinux/