shell基礎教程二十二 read命令的讀取

接收鍵盤或其它檔案描述符的輸入。read命令接收標準輸入（鍵盤）的輸入，或者其他檔案描述符的輸入。得到輸入後，read命令將資料放入乙個標準變數中。

read 命令格式如下：

read [選項]
[變數名]

選項：

-p：「提示資訊」：在等待read輸入時，輸出提示資訊；

-t：秒數：read命令會一直等待使用者輸入，使用此選項可以指定等待時間；

-n：字元數：read命令只接收指定的字元數就會執行；

-s：隱藏輸入的資料，適用於機密資訊的輸入；

更詳細的命令說明,請檢視《linux命令：read-單行讀取資料》

變數名可以自定義。如果不指定變數名，則會把輸入儲存到預設變數reply中；

如果只提供了乙個變數名，則將整個輸入行賦予該變數；

如果提供了乙個以上的變數名，則輸入行分為若干字，乙個接乙個地賦予各個變數，而命令列上的最後乙個變數取得剩餘的所有字元；

#!/bin/bash #testing the read command echo -n "enter you name:" #echo -n 讓使用者直接在後面輸入 read name #輸入的多個文字將儲存在乙個變數中 echo "hello $name, welcome to my program." 執行：# ./read.sh enter you name: wangtao

hello wangtao, welcome to my program.

#!/bin/bash #testing the read -p option read -p "please enter your age: " age days=$[ $age * 365 ] echo "that makes you over $days days old!" 執行：# ./age.sh please enter your age: 23

that makes you over 8395 days old!

#!/bin/bash # entering multiple variables read -p "enter your name:" first last echo "checking data for $last, $first" 執行：# ./read1.sh enter your name: a b checking data

for b, a

#!/bin/bash
# testing the reply environment variable
read -p "enter a number: "
factorial=1 
for(
( count=1; count< = $reply
; count++))
do factorial=$[
$factorial
*$count
]#等號兩端不要有空格
done
echo
"the factorial of $reply is $factorial"
執行：.
/read2.sh
enter a number: 6
the factorial of 6 is 720

#!/bin/bash # timing the data entry if read -t 5 -p "please enter your name: " name #記得加-p引數，直接在read命令列指定提示符 then echo "hello $name, welcome to my script" else echo echo "sorry, too slow!" fi執行： # ./read3.sh please enter your name: sorry, too slow! # ./read3.sh please enter your name: wang

hello wang, welcome to my script

#!/bin/bash
# getting just one character of input
read -n1 -p "do you want to continue [y/n]? " answer
case $answer in
y | y)
echo
echo
"fine, continue on...";;
n | n)
echo
echo
"ok, goodbye"
exit;;
esac 
執行：# ./read4.sh
do you want to continue
[y/n]? y
fine,
continue on...
./read4.sh
do you want to continue
[y/n]? n
ok, goodbye

#!/bin/bash # hiding input data from the monitor read -s -p "enter your passwd: " pass #-s 引數使得read讀入的字元隱藏 echo echo "is your passwd readlly $pass?" ~ 執行：# ./read5.sh enter your passwd:

is your passwd readlly osfile@206?

#!/bin/bash # reading data from a file count=1 cat test | while read line doecho "line $count: $line" count=$[ $count + 1 ] done echo "finished processing the file" 執行： . /read6.sh line 1: the quick brown dog jumps over the lazy fox. line 2: this is a test, this is only a test. line 3: o romeo, romeo! wherefore art thou romeo?

finished processing the file

shell基礎教程二十二 read命令的讀取

Lua教程（二十二） userdata

shell基礎教程

python程式設計基礎之二十二

shell基礎教程二十二 read命令的讀取

Lua教程（二十二） userdata

shell基礎教程

python程式設計基礎之二十二

相關推薦