linux shell 札记

shell 数组

数组索引:

单个元素索引: ${array[n]}

全部元素:   ${array[*]}  或者  ${array[@]}

部分索引: ${array[2:]}

数组所有元素统一加前缀/后缀：

array=( "${array[@]/%/_content}" )

array=( "${array[@]/#/prefix_}" )

流程控制 

for 语句

 for var in $(ls ./home/data)
 do
     sth
 done
 ----------------------------------
 for ((i=0;i<cnt;i++));
 do
     sth
 done
 ----------------------------------
 for loop in 1 2 3 4 5
 do
     echo "The value is: $loop"
 done