Some problems in awk

1、 Write a bash Script to count a text file ceshi.txt The number of occurrences of each word in

awk '{i=1;while(i<=NF){a[$i]++;i++}}END{for(x in a){print x,a[x]}}' ceshi.txt | sort -nk 2

*** Be careful ：*** To separate fields in a row
The following line is directly used as the processing unit , It's wrong.

awk  '{a[$i]++}END{for(j in a){print a[j],j}}' ceshi.txt | sort -nk 1

2、 When the text is not followed , Pay attention to BEGIN

3、 Write a bash Script to count a text file nowcoder.txt The number of letters in is less than 8 's words

It's easier to use scripts directly

#! /bin/bash
string=$(cat aa.txt)
for i in $string
do
if [ ${
    #i} -lt 8 ];then
echo $i
fi
done

among ${#i} Statistics string i Characters of

4、 Write a bash Script to remove a text file nowcoder.txt Empty line in

awk '!/^$/{print $0}' nowcoder.txt