Shell Programming and Scripting

Hello Everybody,

I'm facing a weird problem with the awk command.

I'm trying to execute a simple awk command as follows,

echo 1 2 | awk '{print $2}'

This command prints the output 2.

When i try to execute the same command in a remote server using ssh as follows,

ssh user@host <<HERE
echo 1 2 | awk '{print $2}'
HERE

The output i get is '1 2' instead of just 2.

But when i put the command (echo 1 2 | awk '{print $2}') in a file and use a input redirection as follows,

ssh user@host < cmdfile #cmdfile contains the command

i get the output 2.

Can anyone please clarify this difference in the behaviour of awk command.

I found a partial solution to my problem.

Just to let you know, in this case $2 was being treated as a shell variable and not as awk variable

This works and gives me the output 2

ssh user@host <<HERE
> echo 1 2 | awk '{print \$2}'
> HERE

But i'm still not able to figure out why it works when a command file is given as input to ssh without an escape sequence

The single quotes do not prevent variable expansion in a here document; they do in a script.

In this case, $2 expands to nothing, so the awk command is just '{print }'