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

shell for 循環：

#!第一種寫法 類似C、Javafor ((i=1; i<=100; i ++))do  echo $i  done#!第二種寫法 in應用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 

將循環變量賦值到下一個腳本：

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

1、exec（exec /home/script.sh）：

使用exec來調用腳本，被執行的腳本會繼承當前shell的環境變量。但事實上exec產生了新的進程，他會把主shell的進程資源占用并替換腳本內容，繼承了原主shell的PID號，即原主shell剩下的內容不會執行。

2、source（source /home/script.sh）

使用source或者“.”來調用外部腳本，不會產生新的進程，繼承當前shell環境變量，而且被調用的腳本運行結束后，它擁有的環境變量和聲明變量會被當前shell保留，類似將調用腳本的內容復制過來直接執行。執行完畢后原主shell繼續運行。

3、fork（/home/script.sh）

直接運行腳本，會以當前shell為父進程，產生新的進程，并且繼承主腳本的環境變量和聲明變量。執行完畢后，主腳本不會保留其環境變量和聲明變量。

#!main.sh主體#!/bin/sha=mainecho "a is $a"echo "PID for parent before 2.sh:$$"case $1 in exec)  echo "using exec"  exec ./2.sh ;; *)  echo "using sourcing"  source ./2.sh ;;esacecho "PID FOR parent after 2.sh :$$"echo "now m"

#！2.sh#!/bin/shecho "PID FOR 2.SH:$$"echo "2.sh get a from main.sh is $a"a=2.shexport ab=3.shecho "now 2.sh a is $a"

執行結果：

a is mainPID for parent before 2.sh:1162using sourcingPID FOR 2.SH:11622.sh get a from main.sh is main`這里寫代碼片`now 2.sh a is 2.shPID FOR parent after 2.sh :1162now m

通過for循環，循環變量作為2.sh變量賦值并執行。

#！main主函數#!/bin/sha=0for ((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

輸出結果：

a is 1PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 1now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 2PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 2now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 3PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 3now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 4PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 4now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 5PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 5now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 6PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 6now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 7PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 7now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 8PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 8now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 9PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 9now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sha is 10PID for parent before 2.sh:1339using sourcingPID FOR 2.SH:13392.sh get a from main.sh is 10now 2.sh a is 2.shPID FOR parent after 2.sh :1339now a is 2.sh