简单的bash script，实现以行为单位读入文件，并打印出某一列

简单的script，实现以行为单位读入文件，并打印出某一列

#!/bin/bash
p_arg=0
for arg in $@; do
case $p_arg in
--file) file_name=$arg;;
--col) col=$arg;;
esac
p_arg=$arg
done

echo $file_name
test -e $file_name
if [ $? -ne 0 ]; then
echo "file $file_name doesn't exist!"
fi
#declare -a all_lines
index=0
while read p; do
if [ `echo $p| grep -c '#' ` -eq 0 ]; then
all_lines[$index]=$p
index=$(( index+1 ))
fi
done<$file_name
item_num=${#all_lines[@]}
for item_ix in `seq 0 $((item_num-1))`;do
#echo ${all_lines[$item_ix]}
declare -a item=(${all_lines[$item_ix]})
echo ${item[$col]}
done