Question

I’m trying to get the follow code to read in variables from the user; files to search, a search string, wanted whitespace for output and the amount of fields to be output.

First issue is with the AWK command. If I enter a valid white space such as ” ” (A single space” or “\t” I am given the Unterminated string and syntax error, which only occurs if I request more than one field to be output (otherwise no whitespace is added on).

Secondly GREP seems to be a bit picky when using the search string. I’ve had to add double quotation marks to the start and finish of the variable in order for the entire string to be used.

#!/bin/bash
#****************************************************
#Name:          reportCreator.sh
#Purpose:       Create reports from log files
#Author:        
#Date Written:      11/01/2013
#Last Updated:      11/01/2013
#****************************************************

clear

#Determine what to search for
printf "Please enter input file name(s): "
read inputFile
printf "Please enter your search query: "
read searchQuery
printf "Please enter the whitespace character: "
IFS= read whitespace
printf "Please enter the amount of fields to be displayed: "
read fieldAmount

#Add quotation marks to whitespace and searchQuery
whitespace=\""$whitespace"\"
searchQuery=\""$searchQuery"\"

#Declare variables
declare -i counter=0
declare -a fields[$fieldAmount]
declare -a fieldInsert[$fieldAmount]

#While loop for entering fields
while [[ "$counter" -ne "$fieldAmount" ]]
do
        #Ask for field numbers
        printf "Please enter number for required field $((counter+1)): "
        read fields[$counter]
        ((counter++))
done

#Create function to add '$' before every field and the whitespace characters
function fieldFunction 
{
    for (( counter=0; counter <= ($fieldAmount-1); counter++ ))
    do
        fieldInsert[$fieldAmount]="$""${fields[$counter]}"
        if (( counter!=($fieldAmount-1) ))
        then
            printf "${fieldInsert[*]}$whitespace"
        else
            printf "${fieldInsert[*]}"
        fi  
    done
}
printf "%b\n"

tac $inputFile | grep "$searchQuery" | less #| awk '{print $(fieldFunction)}'

exit 0

Any help would be appreciated.

Answer 1

1. Grep doesn’t understand quotes, so delete the line that adds them to $searchQuery.
2. Use double quotes instead of single quotes for awk, so $(fieldFunction) will expand.

Fixing this (as well as uncommenting the awk, of course), it works:

user@host 15:00 ~ $ cat script
#!/bin/bash
#****************************************************
#Name:          reportCreator.sh
#Purpose:       Create reports from log files
#Author:        
#Date Written:      11/01/2013
#Last Updated:      11/01/2013
#****************************************************

clear

#Determine what to search for
printf "Please enter input file name(s): "
read inputFile
printf "Please enter your search query: "
read searchQuery
printf "Please enter the whitespace character: "
IFS= read whitespace
printf "Please enter the amount of fields to be displayed: "
read fieldAmount

#Add quotation marks to whitespace and searchQuery
whitespace=\""$whitespace"\"

#Declare variables
declare -i counter=0
declare -a fields[$fieldAmount]
declare -a fieldInsert[$fieldAmount]

#While loop for entering fields
while [[ "$counter" -ne "$fieldAmount" ]]
do
        #Ask for field numbers
        printf "Please enter number for required field $((counter+1)): "
        read fields[$counter]
        ((counter++))
done

#Create function to add '$' before every field and the whitespace characters
function fieldFunction
{
    for (( counter=0; counter <= ($fieldAmount-1); counter++ ))
    do
        fieldInsert[$fieldAmount]="$""${fields[$counter]}"
        if (( counter!=($fieldAmount-1) ))
        then
            printf "${fieldInsert[*]}$whitespace"
        else
            printf "${fieldInsert[*]}"
        fi
    done
}
printf "%b\n"

tac $inputFile | grep "$searchQuery" | awk "{print $(fieldFunction)}"

exit 0
user@host 15:01 ~ $ cat file
foo two three four
foo two2 three2 four2
bar two three four
user@host 15:01 ~ $ bash script
Please enter input file name(s): file
Please enter your search query: foo
Please enter the whitespace character:
Please enter the amount of fields to be displayed: 2
Please enter number for required field 1: 4
Please enter number for required field 2: 2

four2   two2
four    two
user@host 15:01 ~ $