problem with redirecting output

Question

I'm writing a script that selects rows from files in a directory which contain patterns $f1, $f2 and $f3 and storing the lines that contain the pattern in a file I want to call as $file_$pattern.xls, for example file1_2.54 Ghz.xls.

#!/bin/bash

#my_script.sh to summarize p-state values

f1="2.54 Ghz"
f2="1.60 Ghz"
f3="800 Mhz"

for f in $f1 $f2 $f3
do
    for file in *.txt  
    do
        grep $f1 $file > ${file}_${f1}.xls
    done
done

Kindly help me with the script.

Answer 1

You can do everything in the shell, no need grep or other external tools

#!/bin/bash

f1="2.54 Ghz"
f2="1.60 Ghz"
f3="800 Mhz"

for file in *.txt
do
    while read -r line
    do
        case "$line" in
            *"$f1"* ) 
                    echo "$line" >> "${file%txt}_${f1}.xls";;
            *"$f2"* ) 
                    echo "$line" >> "${file%txt}_${f2}.xls";;
            *"$f3"* ) 
                    echo "$line" >> "${file%txt}_${f3}.xls";;
        esac
    done < "$file"
done

Answer 2

instead of

for f in $f1 $f2 $f3

use

for f in {$f1,$f2,$f3}

and rename your $f1 in the inner loop!