BASH 如果目录包含文件或不包含文件
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BASH if directory contains files or doesn't
提问by Geofferey
I created a script that executes some commands based on a condition. If directory contains files then run "screen -r" anything else run "screen". Problem is screen sometimes gets executed even when the directory contains files.
我创建了一个脚本，根据条件执行一些命令。如果目录包含文件，则运行“screen -r”，否则运行“screen”。问题是即使目录包含文件有时也会执行屏幕。
if [ "$(ls -A $DIR)" ]; then
screen -r
else
screen
fi
What I want to do is refine it and break it down into two statements. If directory contains files then run screen-r" & if a directory doesn't contain files run "screen"
我想做的是对其进行改进并将其分解为两个语句。如果目录包含文件，则运行 screen-r" & 如果目录不包含文件，则运行 "screen"
if [ "$(ls -A $DIR)" ]; then
screen -r
fi
&
&
if ["$(directory without files)"] ; then
screen
fi
Maybe even a statement that executes based on # of file. If directory contains X amount of files.
甚至可能是基于文件# 执行的语句。如果目录包含 X 个文件。
Can somebody help me out with this? I hope I explained what I want thoroughly.
有人可以帮我解决这个问题吗？我希望我彻底解释了我想要的东西。
Thanks,
谢谢，
Geofferey
杰弗里
Again thank you for all your help, I got it all working now. Here is the final script. It's for the iPhone and an app I'm making called MobileTerm Backgrounder.
再次感谢您的所有帮助，我现在一切正常。这是最终的脚本。它适用于 iPhone 和我正在制作的名为 MobileTerm 后台程序的应用程序。
#Sets up terminal environment?
if [[ $TERM = network || -z $TERM ]]; then
export TERM=linux
fi
# This script automatically runs screen & screen -r (resume) based on a set of conditions.
# Variable DIR (variable could be anything)
DIR="/tmp/screens/S-mobile"
# if /tmp/screens/S-mobile list files then run screen -x
if [ "$(ls -A $DIR)" ]; then
screen -x
fi
#if /tmp/screens/S-mobile contains X amount of files = to 0 then run screen -q
if [ $(ls -A "$DIR" | wc -l) -eq 0 ]; then
screen -q
fi
采纳答案by ДМИТРИЙ МАЛИКОВ
findcould be helpful here:
find在这里可能会有所帮助：
if [[ $(find ${dir} -type f | wc -l) -gt 0 ]]; then echo "ok"; fi
if [[ $(find ${dir} -type f | wc -l) -gt 0 ]]; then echo "ok"; fi
UPD: what is -gt?
UPD：是什么-gt？
man bash-> / -gt/:
man bash-> / -gt/:
arg1 OP arg2
OP is one of -eq, -ne, -lt, -le, -gt, or -ge. These arithmetic binary operators return true if arg1 is equal to, not
equal to, less than, less than or equal to, greater than, or greater than or equal to arg2, respectively. Arg1 and arg2
may be positive or negative integers.
So, -gtis "greater than" boolean function.
所以，-gt是“大于”布尔函数。
回答by Fà Bio
I would use lsand wcthis way:
我会用ls和wc是这样的：
if [ $(ls -A "$DIR" | wc -l) -gt 0 ]; then
screen -r
else
screen
fi
You have to double quote the $DIRvariable otherwise you'll have problems with directory names that contains spaces.
你必须双引号$DIR变量否则你会遇到包含空格的目录名称的问题。
