Bash scripting: feed etherwake program with text file

[LtPitt]

Hi all!

I know this is a very stupid question for a programmer but I am not able to find a solution.

I have a program: etherwake.

It is used to wake on lan a PC using its mac address.

I simply want to "feed" etherwake with a mac address contained in a text file.

I've tried

cat filename | etherwake

etherwake < `cat filename`

without any kind of luck...

I always get:

Specify the Ethernet address as 00:11:22:33:44:55

Of course if I do a cimple cat filename I get a perfect mac address, without blank spaces or any kind of strange characters.

What am I doing wrong?

[Vaphell]

try something like this

etherwake $( < filename )

[sisco311]

You have to pass the mac address to etherwake as an option. So you can use command substitution:

etehrwake $(cat file)

Or if you use BASH:

etehrwake $(< file)

See:

man bash | less +/"^ +Command Substitution"

and
http://mywiki.wooledge.org/CommandSubstitution

Pipes are used to connect the output of a command to the input of another one.
http://mywiki.wooledge.org/BashGuide...ndOutput#Pipes

If your command reads its input from stdin you can use < to redirect the content of a file to it:

command < file

example:

read -r content < file
echo $content

See:
http://mywiki.wooledge.org/Redirection

[LtPitt]

God bless your help!

I loved the solution and loved even more the explanation.

You gave me a fish and taught me how to fish too...

Thanks!