Shell Script Raiders (reading notes)--1.10 debug scripts

Using Sh-x or this bash-x, you can debug a script that outputs and outputs a state for each row while debugging, and It also shows the order in which the commands in the script are executed . You can also use set in the script to set the debug area.

For example, debug the above time_calculate.sh script.

[Email protected] tmp]# sh-x time_calculate.sh

+ + Date +%n

+ start_time=086352877

+ Find/-type f-name ' *.db '

+ + Date +%n

+ end_time=352144614

+ + echo ' scale=6;352144614/10^6 '

+ + BC

+ diff_time=352.144614

+ Echo 352.144614

352.144614

If there is a place to perform the error will be displayed.

For example, modify the time_calculate.sh script, modify the calculated section to an incorrect expression, and set up this section of debugging.

[email protected] tmp]# cat time_calculate.sh

#!/bin/bash

# calculated in microseconds

start_time=$ (Date +%n)

Find/-type F-name "*.db" &>/dev/null

end_time=$ (Date +%n)

#diff_time =$ (echo "scale=6;$ (end_time-strat_time)/10^6" | BC)

set-x   Start debugging from here

Diff_time=$ (echo "scale=6; $ (end_time-strat_time)/10^6 "| BC) ? Make a change here error

Echo $diff _time

set +x ? End Debugging here

Execute script:

[Email protected] tmp]# sh time_calculate.sh

+ + BC

+ + End_time-strat_time

time_calculate.sh:line 8:end_time-strat_time:command not found  ? The front no plus + is the wrong place.

+ + echo ' scale=6;/10^6 '

(standard_in) 1:syntax error

+ diff_time=

+ Echo

+ Set +x

Because/bin/bash can also perform-X debugging, #!/bin/bash Plus-X can always be debugged directly at the beginning of the script. That is #!/bin/bash-x.

Shell Script Raiders (reading notes)--1.10 debug scripts