AWK doesn't work in Bash Script

问题:

I have the following AWK statement in a script:

grep -E $city $DATFILE | awk -F "[\t]+" '($3 >= $minbed) && ($4 >= $minsqft) && ($5 <= $maxprice) && ($6 <= $maxweeks)' $DATFILE | sort -nk5 | less

When I run the script, the output is blank. However, if I run the following:

grep -E Toronto listing.dat | awk -F "[\t]+" '($3 >= 2) && ($4 >= 500) && ($5 <= 900000) && ($6 <= 10)' listing.dat | sort -nk4 | less

It outputs as expected.

I have no idea why this is happening, and I have even replaced the awk statement in the script to echo out the variables to make sure they're passing correctly and they are.

Here is the script thus far:

    #!/bin/bash

    DATFILE=listing.dat

    if [ -f ${DATFILE} ];
    then

            echo -n "Are you looking into anywhere in the GTA, or a specific city?: "
            read uinput

            if [ $uinput == "anywhere" ];
            then
                    echo "You have chosen anywhere"
            elif [ $uinput == "specific" ];
            then
                    echo -n "Which city?: "
                    read city

                    echo -n "Minimum Number of Bedrooms: "
                    read minbed

                    echo -n "Minimum Square Footage (500, 600, etc): "
                    read minsqft

                    echo -n "Maximum Price: "
                    read maxprice

                    echo -n "Maximum Weeks On Market: "
                    read maxweeks

                    echo -n "Sort by (price, sqrft, weeks): "
                    read sortby

                    if [ $sortby == "price" ];
                    then
                            echo -n "Sort by (asc, desc): "
                            read ascdesc
                            if [ $ascdesc == "asc" ];
                            then
                                    grep -E $city $DATFILE | awk -F "[\t]+" '($3 >= $minbed) && ($4 >= $minsqft) && ($5 <= $maxprice) && ($6 <= $maxweeks)' $DATFILE | sort -nk5 | less
                        elif [ $ascdesc == "desc" ];
                        then
                                grep -E $city $DATFILE | awk -F "[\t]+" '($3 >= $minbed) && ($4 >= $minsqft) && ($5 <= $maxprice) && ($6 <= $maxweeks)' $DATFILE | sort -rnk5 | less
                        fi
                fi

        fi

else
        echo "${DATFILE} Not found!"
fi

Can you please help?

Thanks

回答1:

If new to any *nix utility, you can see basic docs using 'man utility_name'; from the man page for 'awk' (man awk):

-v var=val
Assign the value val to the variable var, before execution of the program begins. Such variable values are available to the BEGIN block of an AWK program.

There are other ways to do this, but following the docs your code would be changed to something like:

awk -F "[\t]+" \  
  -v MINBED=$minbed -v MINSQFT=$minsqft -v MAXPRICE=$maxprice -v MAXWEEKS=$maxweeks \
  '($3 >= MINBED) && ($4 >= MINSQFT) && ($5 <= MAXPRICE) && ($6 <= MAXWEEKS)'  

回答2:

I'm not able to comment yet due to reputation. Another thing you can do is escape the single quotes around your variable names. If you're still having trouble with all cities showing up, I believe it's because you're supplying awk with the filename. It looks like you need to take that out and let the grep's output be used as input for your awk. I don't have access to my linux box to test it but:

your line (having $DATFILE supplied twice):

grep -E $city $DATFILE | awk -F "[\t]+" '($3 >= $minbed) && ($4 >= $minsqft) && ($5 <= $maxprice) && ($6 <= $maxweeks)' $DATFILE;

option 1: remove the second $DATFILE, escape single quotes

grep -E $city $DATFILE | awk -F "[\t]+" '($3 >= '$minbed') && ($4 >= '$minsqft') && ($5 <= '$maxprice') && ($6 <= '$maxweeks')';

option 2: you may be able to get rid of the grep entirely, with escaped single quotes. awk's IGNORECASE should be a substitute for grep's -E.

awk -F "[\t]+" 'IGNORECASE = 1;/'$city'/&&($3 >= '$minbed')&&($4 >= '$minsqft')&&($5 <= '$maxprice')&&($6 <= '$maxweeks')';

Like I said, can't test it for syntax at the moment; I hope it helps ya.

Happy hacking!