how so save the cmd results in variable

[vickey_20]

How to store the result of a command executed into a variable.
Ok what exactly I want to do is to store the value of tty into a variable and using substitute that variable in the PS1 so as to see every time in which terminal I m working. The code that I worked up is as below.

tty='tty'
terminal=$(basename($tty))
PS1=" TTY:$terminal #and other things

[i92guboj]

I guess you meant this:

foo=$(basename $(tty))
PS1="${foo} <whatever else>"

[vickey_20]

no its not working that way

[i92guboj]

Are you using bash at all?

If negative try backticks instead, cause I think that the $() notation is a bashism.

foo=`tty`
foo=`basename $tty`
PS1="$foo whatever else"

If not, try to be more descriptive. A simple "doesn't work" tells me nothing about what the problem is.

[vickey_20]

I guess you meant this:

foo=$(basename $(tty))
PS1="${foo} <whatever else>"

dude I did some tweaks in this code and it got me working.
What I did

foo=$(basename $(tty))
PS1="$foo <whatever else>"

But I m still confused where to use $() and where only $varname. Thanks for replying you helped me solve my problem.

[i92guboj]

$() or `...` are used when you want to expand the contents to the result of a command.

For example, when you do var=$(ls) or var=`ls` var will hold the output of ls. Note that backticks are not the same than simple quotes.

If you use var='ls', var will contain the string "ls", and not the output of the ls command.

[vickey_20]

and there is no such thing like $(var) but only $val right. Correct me if I m wrong. Thanks you cleared my concepts

[i92guboj]

and there is no such thing like $(var) but only $val right. Correct me if I m wrong. Thanks you cleared my concepts

Yep.

To set a variable you do this:

var="whatever"

To reference it you use this:

echo "$var"
#or something similar depending on the concrete case,
# for example if $var holds the name of a directory
# you could do
ls "$var"

In cases where there's something adjacent to the variable you can do this to avoid confussion:

var="foo"
echo "${foo}bar"

Curly braces can be used that way to delimit the name of a variable from the surrounding text. For the rest, $var and ${var} are equivalent.

Indeed, there's no $(var) on the sense that you mean it. It's rather var=$(code) or var=`code`