统计各个字符出现的次数

1、统计基础

cat /etc/ssh/sshd_config |grep -o a cat /etc/ssh/sshd_config |grep -o b

2、使用{a..z}可以循环获取26个小写字母

for i in {a..z};do   echo "read it $i" done

3、循环统计每个字母出现的次数

for i in {a..z};do   cat /etc/ssh/sshd_config |grep -o $i |wc -l done

4、把字母打印出来更加直观

for i in {a..z};do   countresult=$(cat /etc/ssh/sshd_config  |grep -o $i | wc -l)   echo -e "$i\t$countresult" done

5、统计大写字母

for i in {A..Z};do   result=`cat /etc/ssh/sshd_config |grep -o $i |wc -l`   echo -e "$i\t$result" done

6、统计每个数字

for i in {0..9};do   result=`cat /etc/ssh/sshd_config |grep -o $i |wc -l`   echo -e "$i\t$result" done

7、统计每个字母、每个数字出现的次数

for i in {0..9} {a..z} {A..Z};do   countresult=$(cat /etc/ssh/sshd_config  |grep -o $i | wc -l)   echo -e "$i\t$countresult" done

注意如果统计到正则字符需要加反斜杠\

cat /etc/ssh/sshd_config |grep --color '\.'