For loop with Multiple IF condition's in Shell scripting

Question

Firstly , In the /tmp/test file path I have the below directories

amb
bmb
cmb

By running the find command, I am getting the below list of files inside these three directories:

amb/eng/canon.amb
bmb/eng/case.bmb
cmb/eng/hint.cmb

I am trying to take each file from this list1 using a for loop and based on the file type, *.amb or *.bmb or *.cmb that particulal IF should execute:

cd /tmp/test
find */ -type f -exec ls {} \; > /tmp/test/list1
for file in `cat /tmp/test/list1`
do
if [ -f *.amb ]
then
sed "s/amb/amx/g" /tmp/test/list1 > /tmp/test/list2
ls /tmp/test/list2 >> /tmp/test/finallist
fi

if [ -f *.bmb ]
then
sed "s/bmb/bmx/g" /tmp/test/list1 > /tmp/test/list2
ls /tmp/test/list2 >> /tmp/test/finallist
fi

if [ -f *.cmb ]
then
sed "s/cmb/cmx/g" /tmp/test/list1 > /tmp/test/list2
ls /tmp/test/list2 >> /tmp/test/finallist
fi

done
echo "*********************"
echo -e "\nFinal list of files after replacing from tmp area"
felist=`cat /tmp/test/finallist`

echo -e "\nfefiles_list=`echo $felist`"

So my final output should be:

amx/eng/canon.amx
bmx/eng/case.bmx
cmx/eng/hint.cmx

Answer 1

I think you're trying to apply a different action depending on the file suffix:

#!/bin/bash
while IFS= read -d '' -r file
do
    # amb/eng/canon.amb
    extn=${file##*.}

    case "$extn" in
    (amb)   finallist+=("${file//amb/amx}") ;;
    (bmb)   finallist+=("${file//bmb/bmx}") ;;
    (cmb)   finallist+=("${file//cmb/bmx}") ;;
    esac
done <( cd /tmp/test && find */ -type f -print0 2>/dev/null )

printf '*********************\n\n'
printf 'Final list of files after replacing from tmp area\nfefiles_list=%s\n' "${finallist[*]}"

Incidentally,

• find */ -type f -exec ls {} \; > /tmp/test/list1 could better be written as find */ -type f -print > /tmp/test/list1, and since you've tagged with linux even that than be reduced further to find */ -type f > /tmp/test/list1. But this will break on strange (but legal) filenames.
• Backticks are deprecated and you should be using $( … ) instead. But even that will break with filenames containing spaces and other special characters.

Answer 2

Use else if, aka elif in bash, e.g.:

if [ $something ]; then
    echo "something"
elif [ $something_else ]; then
    echo "something_else"
elif [ $nothing ]; then
    echo "nothing"
else
    echo "no match"
fi