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shell for循環(huán)、循環(huán)變量值付給其他shell腳本的方法

 更新時間：2018年06月20日 10:29:31   作者：July_whj  
今天小編就為大家分享一篇shell for循環(huán)、循環(huán)變量值付給其他shell腳本的方法，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

本文主要將在shell中如何編寫for循環(huán)，并將循環(huán)變量作為下個shell腳本的參數(shù)。

shell for 循環(huán)：

#!第一種寫法 類似C、Java
for ((i=1; i<=100; i ++))
do
  echo $i  
done
#!第二種寫法 in應(yīng)用
for i in {1..100} 
do 
  echo $i 
done 
#!第三種寫法 seq 使用
for i in `seq 1 100` 
do 
  echo $i 
done

將循環(huán)變量賦值到下一個腳本：

在運(yùn)行shell腳本時候，有三種方式來調(diào)用外部的腳本，exec（exec script.sh）、source（source script.sh）、fork（./script.sh）

1、exec（exec /home/script.sh）：

使用exec來調(diào)用腳本，被執(zhí)行的腳本會繼承當(dāng)前shell的環(huán)境變量。但事實(shí)上exec產(chǎn)生了新的進(jìn)程，他會把主shell的進(jìn)程資源占用并替換腳本內(nèi)容，繼承了原主shell的PID號，即原主shell剩下的內(nèi)容不會執(zhí)行。

2、source（source /home/script.sh）

使用source或者“.”來調(diào)用外部腳本，不會產(chǎn)生新的進(jìn)程，繼承當(dāng)前shell環(huán)境變量，而且被調(diào)用的腳本運(yùn)行結(jié)束后，它擁有的環(huán)境變量和聲明變量會被當(dāng)前shell保留，類似將調(diào)用腳本的內(nèi)容復(fù)制過來直接執(zhí)行。執(zhí)行完畢后原主shell繼續(xù)運(yùn)行。

3、fork（/home/script.sh）

直接運(yùn)行腳本，會以當(dāng)前shell為父進(jìn)程，產(chǎn)生新的進(jìn)程，并且繼承主腳本的環(huán)境變量和聲明變量。執(zhí)行完畢后，主腳本不會保留其環(huán)境變量和聲明變量。

#!main.sh主體
#!/bin/sh
a=main

echo "a is $a"
echo "PID for parent before 2.sh:$$"
case $1 in
 exec)
  echo "using exec"
  exec ./2.sh ;;
 *)
  echo "using sourcing"
  source ./2.sh ;;
esac

echo "PID FOR parent after 2.sh :$$"

echo "now m"
#！2.sh
#!/bin/sh
echo "PID FOR 2.SH:$$"

echo "2.sh get a from main.sh is $a"

a=2.sh
export a
b=3.sh

echo "now 2.sh a is $a"

執(zhí)行結(jié)果：

a is main
PID for parent before 2.sh:1162
using sourcing
PID FOR 2.SH:1162
2.sh get a from main.sh is main`這里寫代碼片`
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1162
now m

通過for循環(huán)，循環(huán)變量作為2.sh變量賦值并執(zhí)行。

#！main主函數(shù)
#!/bin/sh
a=0
for ((i=1; i<=10; i ++))
do
    a=$i
    echo "a is $a"
    echo "PID for parent before 2.sh:$$" 
        echo "using sourcing"
        source ./2.sh
     echo "PID FOR parent after 2.sh :$$"
    echo "now a is $a" 
done

輸出結(jié)果：

a is 1
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 1
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 2
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 2
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 3
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 3
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 4
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 4
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 5
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 5
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 6
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 6
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 7
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 7
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 8
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 8
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 9
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 9
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh
a is 10
PID for parent before 2.sh:1339
using sourcing
PID FOR 2.SH:1339
2.sh get a from main.sh is 10
now 2.sh a is 2.sh
PID FOR parent after 2.sh :1339
now a is 2.sh

以上這篇shell for循環(huán)、循環(huán)變量值付給其他shell腳本的方法就是小編分享給大家的全部內(nèi)容了，希望能給大家一個參考，也希望大家多多支持腳本之家。

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