赋值
astr="Hello World" bstr=Hello
substring
echo $astr echo ${astr:6} echo ${astr:0:6}
replace
echo ${astr/s1/s2} # ReplaceFirst echo ${astr//s1/s2} # ReplaceAll
contact
cstr="$astr+$bstr"
Shell 字符串操作
原文：https://www.cnblogs.com/stdpain/p/12080103.html
