use external file with variables

Question

The following is iptable save file, which I modified by setting some variables like you see below.

-A OUTPUT -o $EXTIF -s $UNIVERSE -d $INTNET -j REJECT

I also have a bash script which is defining this variables and should call iptables-restore with the save file above.

#!/bin/sh

EXTIF="eth0"
INTIF="eth1"

INTIP="192.168.0.1/32"
EXTIP=$(/sbin/ip addr show dev "$EXTIF" | perl -lne 'if(/inet (\S+)/){print$1;last}');

UNIVERSE="0.0.0.0/0"
INTNET="192.168.0.1/24"

Now I need to use

/sbin/iptables-restore <the content of iptables save file>

in bash script and somehow insert the text file on top to this script, so the variables will be initialized. Is there any way to do that?

UPDATE: even tried this

/sbin/iptables-restore -v <<-EOF;

$(</etc/test.txt)

EOF

Reposted here.

Dennis Williamson
– Dennis Williamson

2011-03-14 04:19:04 +00:00
Commented Mar 14, 2011 at 4:19 — Dennis Williamson
– Dennis Williamson, Commented Mar 14, 2011 at 4:19

freiheit · Accepted Answer · 2011-03-14 17:10:26Z

2

Something like this:

while read line; do eval "echo ${line}"; done < iptables.save.file | /sbin/iptables-restore -v

or more nicely formatted:

while read line
  do eval "echo ${line}"
done < iptables.save.file | /sbin/iptables-restore -v

The eval of a string forces the variable expansion stuff.

answered Mar 14, 2011 at 17:10

freiheit

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Comments

gavenkoa · Accepted Answer · 2011-10-01 10:48:40Z

2

Use . (dot) char to include one shell script to another:

  #!/bin/sh
  . /path/to/another/script

edited Oct 1, 2011 at 10:48

answered Mar 13, 2011 at 13:38

gavenkoa

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3 Comments

Dennis Williamson Over a year ago

The first line of your example is confusing.

user123444555621 Over a year ago

That probably should be #!/bin/sh

Pablo Over a year ago

the text within script is not another script but just data, containing $variables.

Dennis Williamson · Accepted Answer · 2011-03-14 07:34:56Z

1

In your shell script:

. /path/to/variable-definitions
/sbin/iptables-restore < $(eval echo "$(</path/to/template-file)")

or possibly

/sbin/iptables-restore < <(eval echo "$(</path/to/template-file)")

edited Mar 14, 2011 at 7:34

answered Mar 13, 2011 at 13:58

Dennis Williamson

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10 Comments

Pablo Over a year ago

doesn not really work, it is still waiting for user input from stdin

Dennis Williamson Over a year ago

@Michael: Can you edit your question to show more specifically what it is you're trying to do and what the steps to achieve it are? There seems to be something missing in your question.

Pablo Over a year ago

@Dennis: actually it's quite simple what I want. Just to read data and put into certain position. Guess I will have to use EOF markers...

Dennis Williamson Over a year ago

@Michael: I still don't see how the first line (the one that starts with -A) comes into play. Normally, you'd use iptables-restore < saved-file.

Pablo Over a year ago

@Dennis: but in saved-file you can not specify shell variables... I've modified the saved-file and put some variables wihch I needed.

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