シェルで配列をトラバースするいくつかの方法

#! /bin/bash
# $1 for the file directory
# Execute eg.
# sh your_shell.sh /user/lib/
 
echo "Start time: `date '+%Y-%m-%d %H:%M:%S'`"
# 1. Get all files
files=`ls $1`
 
# 2, define 1 array variable
declare -a array_files01
 
 
# array index initialized to 0
m1=0
 
 
# traverse
for ays in ${files}; do
{
 # Get the length of the array
 num_1=${#array_files01[@]}
 
 # Add elements to the array, index takes +1 each time
 array_files01[m1]=${ays};
 m1=`expr ${m1} + 1`;
 
 fi
}
done
 
echo "End of allocation array time: `date '+%Y-%m-%d %H:%M:%S'`"
# Print prompt message
echo "1 array length: ${#array_files01[@]}"
 
# The first traversal: normal
for i in ${array_files01[@]}; do
 echo $i
done 
 
# Second traversal: abnormal
for i in ${array_files01}; do
 echo $i
done 

################### The first #######################
for i in ${array[@]}
# can also be written for element in ${array[*]}
do
echo $i
done

################## The second ########################
for i in ${array[*]}
do
echo $i ;
done
 
################## third ########################
for(( i=0;i<${#array[@]};i++)) do
#${#array[@]} gets the length of the array for looping
echo ${array[i]};
done;

i=0 
while [ $i -lt ${#array[@]} ] 
# Enter the loop body when the variable (subscript) is less than the length of the array
do 
 echo ${ array[$i] } 
 #Print the elements of the array by subscript
 let i++ 
done