Debugging a script with noexec

Shell Programming and Scripting
1

Newbie question. I cannot get "set -n" or "set -noexec on" to work on Linux or AIX! According to the man page and what I read online, it should inform me of syntax errors without executing commands in your script.

So, can someone PLEASE explain why this does not work?

======================================
# WHAT I SHOULD SEE

rochatk:/tmp # cat t1
#set -n

echo test
ech test1

rochatk:/tmp # ./t1
test
./t1: line 4: ech: command not found

# REMOVE COMMENT FROM SET COMMAND

rochatk:/tmp # vi t1
rochatk:/tmp # cat t1
set -n

echo test
ech test1

rochatk:/tmp # ./t1
rochatk:/tmp #

======================================

Why don't I see the error after "set -n" is enabled?
Thank you for your help!

2

There's nothing wrong with the syntax, though. If 'ech' actually existed on your system, it would be run.

So syntax checking alone won't catch this error.

3

I see, you are correct. I tried a bad syntax example and it worked as expected

if [ 3 -eq 4 ];
  echo wrong
fi

DOES yield a syntax error.

So, this isn't as useful as I hoped if it doesn't catch ALL the errors, but thank you for your help in understanding why.