How to Debug a Shell Script ??

How to Debug a Shell Script ??

We can debug shell script by using “set -xv” command inside shell script or using -xv on command line while executing script.

Debug Shell Script by adding Command :

$ cat checkdebug.sh

#!/bin/bash

set -xv  # << This will enable debug
cd /var/log/
for i in "*.log"; do
 du -sh $i
done

Execute above Script and watch the output:

# sh checkdebug.sh

[Sample Output]

cd /var/log/
+ cd /var/log/
for i in "*.log"; do
 du -sh $i
done
+ for i in '"*.log"'
+ du -sh boot.log mysqld.log post111.log post1121.log yum.log
0       boot.log
32K     mysqld.log
0       post111.log
0       post1121.log
4.0K    yum.log

Debug Shell Script using Option:

Using this option we don’t need to add “set -xv” in shell script. Just create a shell script like below

$ cat checkdebug2.sh

#!/bin/bash

cd /var/log/
for i in "*.log"; do
 du -sh $i
done

and Execute like below

# sh -xv checkdebug2.sh

[Sample Output]

#!/bin/bash

cd /var/log/
+ cd /var/log/
for i in "*.log"; do
 du -sh $i
done
+ for i in '"*.log"'
+ du -sh boot.log mysqld.log post111.log post1121.log yum.log
0       boot.log
32K     mysqld.log
0       post111.log
0       post1121.log
4.0K    yum.log