shell脚本学习-练习写一个脚本1

# 1.依次展示/etc/passwd中的用户名和UID。格式如：Hello,$USER,your UID is $UID.

# 2.统计一个有多少个用户

#!/bin/bash
#Program Description:   
#Author: Created by ctu_lzq 
#Date: 2018/11/15
FILE="/etc/passwd"
LINES=`cat $FILE |wc -l`
#for i in `seq 1 $LINES`;
for ((i=1;i<=$LINES;i++));
do
    userlist=`sed -n "$i""p" $FILE|awk -F: '{print $1}'`
    uidlist=`sed -n "$i""p" $FILE|awk -F: '{print $3}'`
    echo "Hello,$userlist,your UID is $uidlist"
done
echo  "there are $LINES users"

结果如：
[root@study learnshell]# bash test.sh 
Hello,root,your UID is 0
Hello,bin,your UID is 1
Hello,daemon,your UID is 2
Hello,adm,your UID is 3
Hello,lp,your UID is 4
Hello,sync,your UID is 5
Hello,shutdown,your UID is 6
Hello,halt,your UID is 7
Hello,mail,your UID is 8
Hello,uucp,your UID is 10
Hello,operator,your UID is 11
Hello,games,your UID is 12
Hello,gopher,your UID is 13
Hello,ftp,your UID is 14
Hello,nobody,your UID is 99
Hello,dbus,your UID is 81
Hello,usbmuxd,your UID is 113
Hello,rpc,your UID is 32
Hello,rtkit,your UID is 499
Hello,avahi-autoipd,your UID is 170
Hello,vcsa,your UID is 69
Hello,abrt,your UID is 173
Hello,rpcuser,your UID is 29
Hello,nfsnobody,your UID is 65534
Hello,haldaemon,your UID is 68
Hello,ntp,your UID is 38
Hello,apache,your UID is 48
Hello,saslauth,your UID is 498
Hello,postfix,your UID is 89
Hello,gdm,your UID is 42
Hello,pulse,your UID is 497
Hello,sshd,your UID is 74
Hello,tcpdump,your UID is 72
Hello,mysql,your UID is 27
Hello,nginx,your UID is 496