Bash - Start a new instance of a command in anothe

问题:

I have a simple bash script (test.sh) set up like this:

#!/bin/bash
args=("$@")
if [[ ( ${args[0]} = "check_capture" ) ]]; then
  watch -n 1 'ls -lag /home/user/capture0'
  watch -n 1 'ls -lag /home/user/capture1'
  watch -n 1 'ls -lag /home/user/capture2' 
  exit
fi

Files are continuously being written to these target locations capture 0, capture 1, and capture 3. I want to be able to watch these directories using ls command continuously on 3 seperate terminals, and once I run this script (test.sh) from the current terminal, I want it to exit.

Right now it is blocked by each wait, which I know is a blocking bash command waiting for user input control-c. Is there a way I can have the 3 watch commands be executed in seperate terminals then reach the exit statement?

回答1:

You can start several instances of the terminal in background, each one running a command, like this:

if [[ ... ]]; then
    xterm -e 'watch -n 1 "ls -lag /home/user/capture0"' &
    xterm -e 'watch -n 1 "ls -lag /home/user/capture1"' &
    ...
    exit
fi

Check man xterm:

-e program [ arguments ... ]

This option specifies the program (and its command line arguments) to be run in the xterm window. It also sets the window title and icon name to be the basename of the program being executed if neither -T nor -n are given on the command line. This must be the last option on the command line.

The same option works also for xfce-terminal and gnome-terminal.

In addition, xterm (and others) also support setting the title of the window, position, size (called geometry), colors, fonts, and many, many other features.