Awk help to process a resource file by a shell script

[Rui Vilao]

Greetings to all awk and sed gurus!

I have a general resource file of the following format that must be read and sourced by several shell scripts:


Loading.NRT_DAYS=1
Loading.POLLING_INTERVAL=5
#Loading.POLLING_INTERVAL=30
Loading.MASK=*

Running.NRT_DAYS=1
Running.POLLING_INTERVAL=5
#Running.POLLING_INTERVAL=30

…

Where:
Line beginning with #, are comments
Each entry has the format: Script_name.variable_name=value

I want to write within my shell script an awk command to read and parse this file. For each line matching the script name, it will:
export variable_name=value
…

I am quiet proficient in shell scripting and tha kind of parsing is complex because * can be a value…
I believe the parsing can be achieved by a simple awk command…


Any help/suggestion is highly appreciated.

Thanks in advance for your help,

Kind Regards,

Rui

[Rodney Hills · Accepted solution]

Try this-

awk -F= '!/#/{print "export " $1 "=''" $2 "''" }' /tmp/export$$
. /tmp/export$$

HTH

-- Rod Hills

[curt larson_1]

why parse a file at all?

create a seperate file for loading, running, etc.; put the files all in the same directory

and instead of lines like:
Running.NRT_DAYS=1

make them like this:
export NRT_DAYS=1

then exporting the variables is as easy as:

. $dirWhereFilesAre/$yourScriptName

just a suggestion

[john korterman]

Hi,
no gurus around here...
But the attached script may serve as a starting point. Try it with your input file as $1.

regards,
John K.

[Greg Vaidman]

Rod, I think you missed the part about matching the script_name...

Some of the other guys suggest sourcing in your resource file(s) directly, which will work fine, assuming you have the capability to make this change (it's a manually generated file, and not generated by some closed-source app).

However, this mechanism assumes a level of trust that noone has put malware-type commands into the resource file(s), as they would be happily executed with the permissions of the user running the script. Of course, if the write permissions on the resource file(s) are as restrictive or stronger than execute permissions on the script, then this isn't a big deal.

Just something to think about...

--Greg

[Stuart Browne]

To add confusion to this is shell environment space protection.

Which shell are you going to use?

Generally you could use something like Rodney's solution (expanding upon that a little) in `` shell-execution, but some shells might not allow it.

[Amit Agarwal_1]

$ cat myscript
!/usr/bin/awk
FILENAME=$1
awk -F'.' `
BEGIN { script_name=$FILENAME }
{ if($1==script_name) 'print "export "$2' }
`

$ myscript <script name>

I am not sure if the awk uses forward quotes or single quotes for instruction. You might try it. Sorry, I haven't tested this program. But am sure it will help you in writing one.

[Amit Agarwal_1]

Okay, I got access to a system. Here is the solution

$ cat myscript
FILENAME=$1
awk -v script_name=$FILENAME -F "." '
{ if($1==script_name) print "export " $2 }
'< resource_file

Output:
========
$ ./myscript Loading
export NRT_DAYS=1
export POLLING_INTERVAL=5
export MASK=*
$ ./myscript Running
export NRT_DAYS=1
export POLLING_INTERVAL=5

I hope this helps.

Amit

[Muthukumar_5]

For Example, Details are in resource file as,

resource.log
Loading.NRT_DAYS=1
Loading.POLLING_INTERVAL=5
#Loading.POLLING_INTERVAL=30
Loading.MASK=*

Running.NRT_DAYS=1
Running.POLLING_INTERVAL=5
#Running.POLLING_INTERVAL=30

Then, You can try in each script file as,

---- Loading file ---
File=$(basename $0 | cut -d"." -f1)
for var in `grep $FILE resource.log | cut -d"." -f2-`
do
variable=$(echo $var | cut -d"=" -f1)
value=$(echo $var | cut -d"=" -f2)
export $variable=$value
done

Keep the same in all required files.

hth.