jbowers

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I have a script that generates a new template script. I have no problems passing variables from the generating script to the template script by prefixing said variables with \, i.e. AA1="\$LINENO" However, when I attempt to pass the following variable it is expanded regardless of any restriction that I use to restrict the expansion:
message=`cat /error_messages/test_msg.txt`

The template script is expanded to:
message=This is a test of an error message.

The result I am looking for is:
message=`cat /error_messages/test_msg.txt`

Thank you for your assistance.

neonsignal

I'm not sure I understand the problem? Why can't you just quote it:

Can you provide more detail?

jbowers

I have tried message='`cat /error_messages/test_msg.txt`' and get the following result:
message='This is a test of an email error message. ', the variable "message" is an expansion of the path.

Since the code is within a function I tested it outside of the function and the results are the same.

The following code does not result in expansion: message=/error_messages/test_msg.txt. So the problem as I see it, is when the code is back quoted and cat is inserted as a command the script that generating the template code executes cat. I believe what is required is to isolate `cat ......` so that the generating script does not execute cat. I use kate as an editor. I can can see that cat is being treated as a command in the generating script.

Thank you for your assistance.

Disillusionist

have you tried:
Alternatively, please can you provide a larger piece of sample code so that we can try things out.

jbowers

Disillusionist,

Your code resolved the problems, I knew that there was a solution just could not figure it out.

Thank you!!!

zhjim

Just to have that sorted. everythign between ` and ` is run in a subshell. ` IS NO QOTATION in bash. Use ' or " to quote things.
' takes everything between two of them as it is. " allows for interpretation like $variable.

Cheers Zhjim

P.S
to differ between ` and ' use $(your command to run). This does the same like `your command to run`

jbowers

This explanation is the best that I have encountered. An example or two might help others better understand the concept.

Thank you,
jbowers

zhjim

Okay but just some quick ones I'am having migraine headache For further explanations look at :
http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html
http://tldp.org/guides.html#abs

Quotation in shell (BASH)
There are two kinds of quotation marks one is ' and the other is " They should always come in pairs say start of quotation and end of quotation else the shell will not be happy and provide a < as a prompt (after hitting enter).
examples:
'example'
"example"

Diffrence between the two is how they esacpe special shell characters like $ * ?. ' escapes everything. So no evaluation is done. With " everything will get expanded
example:
prints
prints
Prepare to not mix up ` and '!
` is the start of shell expansion. Everything between `some command` will be run in a subshell. If you want that better use $(somecommand) this is easier to distinguish.

Last one is \ this tells the shell to escape the following character so that it's not interpreted by the shell.
example
will print
Now of to bed or to

http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html
http://tldp.org/guides.html#abs

jbowers

Thank you