将 mail.txt 的内容寄给 user2 同时 cc 给 user1 。如果将这一行指令设成 cronjob 就可以定时将备忘录寄给系统使用者。 mail -s 标题 -c user1 user2 > expr length "this is a test"
14 ### 数字商数 shell>> expr 14 % 9
5 ### 从位置处抓取字串 shell>> expr substr "this is a test" 3 5
is is ### 数字串 only the first character shell>> expr index "testforthegame" e
2 ### 字串真实重现 shell>> expr quote thisisatestformela
thisisatestformela
名称: tr ### 1.比方说要把目录下所有的大写档名换为小写档名? 似乎有很多方式,"tr"是其中一种: #!/bin/sh dir="/tmp/testdir";
files=`find $dir -type f`;
for i in $files
do
dir_name=`dirname $i`;
ori_filename=`basename $i`
new_filename=`echo $ori_filename | tr [:upper:] [:lower:]` > /dev/null;
#echo $new_filename;
mv $dir_name/$ori_filename $dir_name/$new_filename
done ### 2.自己试验中...lowercase to uppercase tr abcdef...[del] ABCDE...[del]
tr a-z A-Z
tr [:lower:] [:upper:] shell>> echo "this is a test" | tr a-z A-Z > www
shell>> cat www
THIS IS A TEST ### 3.去掉不想要的字串 shell>> tr -d this ### 去掉有关 t.e.s.t
this man
man
test
e ### 4.取代字串 shell>> tr -s "this" "TEST"
this
TEST
th
TE