Different Operators

caponewgp · 09-05-2009, 08:32 PM

I was wondering if anyone could help me with the differences between "$PWD" '$PWD' `$PWD`. Basically I just don't understand exactly how '' "" `` change the output of the command. Thanks again

paulsm4 · 09-05-2009, 08:54 PM

Hi -

Quote:

# Prints the contents of shell variable "PWD" (the current directory)
echo $PWD
/tmp

Quote:

# Equivalent: the double quotes simply make sure that, if there were multiple "words" (like "aaa" "bbb" and "ccc"), they would all be part of the same, single string:
echo "$PWD"
/tmp

Quote:

# The single quotes PREVENT the shell from "expanding" $PWD:
echo '$PWD'
$PWD

Quote:

# The back-quotes expand "$PWD" first, then try to use it as an argument:
# BAD EXAMPLE:
echo `$PWD`
bash: /tmp: is a directory

'Hope that helps .. PSM