Pass multiple arguments from a file to while loop in Shell

Question

I have a file containing couple of words like :

server1 location1
server2 location2

I need to pass these in a while loop.

How do we assign them to two separate variables? Something like this may be

while read server,location
do
echo $server is in $location
done <file

I'm able to work with 1 variable very fine, but couldn't figure out this one.

Any help would be appreciated.

P.P · Accepted Answer · 2015-12-21 11:36:02Z

2

You need to use space between variables, not comma:

while read -r server location
do
echo "${server}" is in "${location}"
done <file

Note that first word will be read into server and "everything else" will go into location. So if your file happens to contain more than two words then you may want to ignore the rest with a dummy variable:

while read -r server location dummy
do
echo "${server}" is in "${location}"
done <file

answered Dec 21, 2015 at 11:36

P.P

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9 Comments

mhawke Over a year ago

Are you able to parse the whole file using read without dropping the rest of the line? I think that's what the OP is after.

P.P Over a year ago

I have edited the post to make it clear (you can see from the edit history for what OP meant to ask). It did look like what you are saying. But it's a due to poor formatting in the question. Sorry!

mhawke Over a year ago

I might be missing something, but I don't see that in the edit history. I see that you have edited the question not the OP???

P.P Over a year ago

@mhawke All I did was format those two lines OP had. You have to see the source of the history, not just history before accusing me of edting it to suit my answer.

P.P Over a year ago

@mhawke Here's the link for you: source. If you still don't believe, flag it to a moderator.

|

mhawke · Accepted Answer · 2015-12-21 12:05:57Z

1

I'm a bit rusty with shell scripting so I doubt that this is the best way, but you can do it like this:

set $(cat file)
while [ $# -gt 0 ]
do
    echo $1 is in $2
    shift 2
done

Another way is to use awk:

awk '{for (i=1; i<NF; i+=2) printf "%s is in %s\n", $i, $(i+1);}' file

edited Dec 21, 2015 at 12:05

answered Dec 21, 2015 at 11:40

mhawke

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