使用Bash显示进度指示器
问题描述：
使用仅bash脚本，如何提供bash进度指示器?
Using a bash only script, how can you provide a bash progress indicator?
所以我可以运行bash形式的命令，并且在执行该命令时，让用户知道仍在发生某些事情.
So I can run a command form bash, and while that command is executing let the user know that something is still happening.
答
在此示例中，使用SCP，我演示了如何获取进程ID(pid)，然后在该进程运行时执行某些操作.
In this example using SCP, I'm demonstrating how to grab the process id (pid) and then do something while that process is running.
这将显示一个简单的旋转图标.
This displays a simple spinnng icon.
/usr/bin/scp me@website.com:file somewhere 2>/dev/null &
pid=$! # Process Id of the previous running command
spin[0]="-"
spin[1]="\\"
spin[2]="|"
spin[3]="/"
echo -n "[copying] ${spin[0]}"
while [ kill -0 $pid ]
do
for i in "${spin[@]}"
do
echo -ne "\b$i"
sleep 0.1
done
done
威廉·珀塞尔的解决方案
William Pursell's solution
/usr/bin/scp me@website.com:file somewhere 2>/dev/null &
pid=$! # Process Id of the previous running command
spin='-\|/'
i=0
while kill -0 $pid 2>/dev/null
do
i=$(( (i+1) %4 ))
printf "\r${spin:$i:1}"
sleep .1
done