Shell Script debugging

Bash is the default scripting language in a Linux system, and since it is a programming language, debugging of scripts is essential. Here's a simple debugging approach to bash:

1 using Bash's parameter-X, such as

Bash-x a.sh

+ for A in ' bafa{1..4} '

+ ID BAFA1

+ Echo ' bafa1 is exits '

BAFA1 is exits

+ for A in ' bafa{1..4} '

+ ID BAFA2

+ Echo ' bafa2 is exits ' #+ means print out each line of script

BAFA2 is exits #打印出脚本执行的结果

+ for A in ' bafa{1..4} '

+ ID Bafa3

+ Echo ' bafa3 is exits '

Bafa3 is exits

+ for A in ' bafa{1..4} '

+ ID BAFA4

+ Echo ' bafa4 is exits '

BAFA4 is exits

+ + Date ' +%f%T ' #++ represents the call

+ echo ' 2017-03-27 14:03:34 '

2017-03-27 14:03:34

2 If the script is too long, use set-x to open the script for trace debugging

such as: Vim a.sh

#!/bin/bash

For a in bafa{1..4};d o

If ID $a &>/dev/null;then

echo "$a is exits"

Else

Useradd $a && echo "$a" | passwd--stdin $a &>/dev/null

echo "$a is create OK"

Fi

Done

Set-x

echo "$ (date +"%F%T ")"

Set +x

Increased execution permissions: chmod +x a.sh

./a.sh

BAFA1 is exits

BAFA2 is exits

Bafa3 is exits

BAFA4 is exits

+ + Date ' +%f%T '

+ echo ' 2017-03-27 14:17:27 '

2017-03-27 14:17:27

+ Set +x

This article from "10,000 years too long, seize" blog, please be sure to keep this source http://zengwj1949.blog.51cto.com/10747365/1910716

Shell Script debugging