I have a variable: pkgname=com.google.android.youtube
And the command is
su -c "stockapp=$(pm path $pkgname | grep base | sed 'sed 's/package://g')"
I have checked the variable is passed inside the double quotes but not to $() How can I pass the variables there there??
Your code doesn't make sense.
Maybe you meant:
stockapp=$(
PKG=$pkgname su -c 'pm path "$PKG"' |
sed '/base/!d; s/package://g'
)
That is, run the login shell of root as root with -c and pm path "$PKG" as arguments (assuming the login shell of root is Bourne-like) and PKG=contents-of-pkgname in its environment, and process its output to remove all the lines that don't contain base, and for the other lines, remove all occurrences of package:, and assign that output to the $stockapp variable in your shell script.
su) is called. Your variable,stockapp, is set within the shell thatsuspawns, and then it is immediately destroyed together with the shell when it terminates. It is unclear what you want to do.