【Linux】Shell - 脚本练习 - 截取文件内容

写一个脚本

依次向/etc/passwd中的每个用户问好，并且说出对方的ID是什么

例如：Hello root, your UID is0.

方法1：使用awk指定分隔符

cat /etc/passwd | awk -F ":" '{print "Hello " $1 ", your UID is " $3 }';

# awk -F ":" '{print "Hello " $1 ", your UID is " $3 }' /etc/passwd

方法2：使用cut分割每行内容

# /bin/bash

FILE=/etc/passwd

LINES=`wc -l ${FILE} | cut -d" " -f1`

for I in `seq 1 ${LINES}`

do

  currentline=`head -${I} ${FILE} | tail -n1`

  username=`echo ${currentline} | cut -d: -f1`

  userid=`echo ${currentline} | cut -d: -f3`

  echo "hello $username,your UID is $userid"

done

exit 0;