How to pass BASH shell variables into AWK statement

You have to use -v, Getting shell variables into awk may be done in several ways. Some are better than others.

This is the best way to do it (Please note use a space after -v or it will be less portable. E.g., awk -v var= not awk -vvar)

# your shell variables
marker1="###___showhost___###"
marker2="###___showhostset___###"

# and passing them to awk
awk -v market1="$market1" -v market2="$market2" '
       $0 ~ "^"market1{found=1;next}
       $0 ~ "^"market2{found=0}found' file.in

Example:

akshay@db-3325:~$ foo="this is my shell variable"
akshay@db-3325:~$ awk -v myvar="$foo" 'BEGIN{print myvar}'
this is my shell variable