Linux 中的命令链接操作符

&& 与 || 配合

eg:
cat test.sh 
#!/bin/bash
[ -e /etc/hosts ] && echo "ok" || echo "fail"

bash test.sh 
ok

eg:
cat test.sh 
#!/bin/bash
[ -e /etc/hostssssss ] && echo "ok" || echo "fail"

bash test.sh 
fail

注意这里 && 必须在 || 之前

命令合并操作符 {}

[ -f /home/tecmint/Downloads/xyz1.txt ] || {touch /home/tecmint/Downloads/xyz.txt; echo "The file does not exist"}
“The file does not exist”