Eight, Shell Script advanced programming combat Part VIII

First, use a for loop to create a file named 10 oldboy-x in / oldboy directory

#!/bin/sh
[ ! -d /oldboy ] && mkdir -p /oldb
for i in `seq 10`
do
  touch  /oldboy/oldboy-${i}.html
done

 

 Second, to achieve a for loop oldboy into linux, extension of HTML, for loop can not appear oldboy font

#!/bin/sh
cd /oldboy
for file in `ls *.html`
do
  mv $file `echo $file |sed 's#oldboy#linux#g'|sed 's#html#HTML#g'`
done

 

 Third, create a batch system 10 oldboy01-10 account password and can not be the same

  #!/bin/sh
for n in `seq -w 10`
do
 useradd  oldboy$n &&\
 echo "djw$n" |passwd --stdin oldboy$n
done

Fourth, batch create 10 accounts oldboy01-10 system password and a random password

#!/bin/sh
for n in `seq -w 10`
do
 userdel -r oldboy$n &&\
 useradd oldboy$n &&\
 echo "$RANDOM"|md5sum|cut -c 1-8|passwd --stdin oldboy$n

done

Fifth, the method for generating random numbers

RANDOM  

openssl rand -base64 8/10/13

date +%s%N

/proc/sys/kcrncl/uuid