Reading lines in a loop

[Sachin Patel]

HI

I am trying to read line by line in for loop

Here is my section of netgroup file which has \ at the end

B132 (alderon.vdgc.com,-,) (alderon,-,) (babafett.vdgc.com,-,) (babafett,-,) (c3po.vdgc.com,-,) (c3po,-,) (chewie.vdgc.com,-,) (chewie,-,) (droid.vdgc.com,-,) (droid,-,) (dthstar1.vdgc.com,-,) (dthstar1,-,) (endor.vdgc.com,-,) (endor,-,)

while read line
do
echo "$line"
done < file_name

It will gives me all line without \ at the end.

How can I solve this?

Sachin

[Rodney Hills]

Since \ is used for special characters within a shell command line, I would say either strip the \ or add another to the end of the line.
\\ will return a single \.

-- Rod Hills

[S.K. Chan]

Not answering your question but just wanted to quickly point out (you may know this already) that you can make the "netgroup" file looks nicer. For example ..
B132(alderon.vdgc.com,-,) (alderon,-,)(babafett.vdgc.com,-,) (babafett,-,).......
endor.vdgc.com,-,) (endor,-,)

B2000(venus.vdgc.com,-,) (venus,-,)(mars.vdgc.com,-,) (mars,-,).......
(rock.vdgc.com,-,) (rock,-,)

That way is more readable (that's how I got mine done).

[Sachin Patel]

Woo, Even cut paste didn't work either.

It suppose to be
B132 (alderon.vdgc.com,-,) (alderon,-,) (babafett.vdgc.com,-,) (babafett,-,) (c3po.vdgc.com,-,) (c3po,-,) droid.vdgc.com,-,) (droid,-,)
And so on...

Rodney, I can't use \\ on netgroup file. I do not want to change original file to make my script work.

Sachin

[S.K. Chan]

Sorry Sachin, the output is meant to look like ..
B132
(alderon.vdgc.com,-,) (alderon,-,)
(babafett.vdgc.com,-,) (babafett,-,)
.......
endor.vdgc.com,-,) (endor,-,)

B2000
(venus.vdgc.com,-,) (venus,-,)
(mars.vdgc.com,-,) (mars,-,)
.......
(rock.vdgc.com,-,) (rock,-,)

[Rodney Hills · Accepted solution]

According to the "ksh" man page, you can use-

read -r line

The -r indicates raw and it will leave "\" characters alone.

-- Rod Hills

[harry d brown jr]

PERL time

#!/path2perl
open(INFILE, "while () {
print $_;
}

live free or die
harry

[Sachin Patel]

Look like "\" is not working in this message area either

It suppose to be
B132 "\"
(alderon.vdgc.com,-,) (alderon,-,) "\"
(babafett.vdgc.com,-,) (babafett,-,) "\"
(c3po.vdgc.com,-,) (c3po,-,) "\"
droid.vdgc.com,-,) (droid,-,) "\"

And so on...
So third try with double quote around my \\.

Sachin

[Sachin Patel]

Thanks Rodney,
That works.
SK I have my netgroup file same way as you trying to describe. Harry no perl this time.

Sachin

[James R. Ferguson]

Hi Sachin:

Have a look at the man pages for 'read'. The '-r' option causes the backslach "\" character not to be treated in any special
way. That is, to consider each backslash to be part of the input line.

Regards!

...JRF...

[Hai Nguyen_1]

Sachin,

Can you try this? It should work, assuming that the "\" is at the end of the line if any. Otherwise, you can try again without the "$" sign in the sed command.

cat file_name | sed 's:\\$:\\\\:' | while read line
do
echo "$line"
done

Hai