bash: How to transfer/copy only the file names to separate similar files? - linux

Question

I've some files in a folder A which are named like that:
001_file.xyz
002_file.xyz
003_file.xyz
in a separate folder B I've files like this:
001_FILE_somerandomtext.zyx
002_FILE_somerandomtext.zyx
003_FILE_somerandomtext.zyx
Now I want to rename, if possible, with just a command line in the bash all the files in folder B with the file names in folder A. The file extension must stay different.
There is exactly the same amount of files in each folder A and B and they both have the same order due to numbering.
I'm a total noob, but I hope some easy answer for the problem will show up.
Thanks in advance!
ZVLKX
*Example edited for clarification

Answer 1

An implementation might look a bit like this:
renameFromDir() {
useNamesFromDir=$1
forFilesFromDir=$2
for f in "$forFilesFromDir"/*; do
# Put original extension in $f_ext
f_ext=${f##*.}
# Put number in $f_num
f_num=${f##*/}; f_num=${f_num%%_*}
# look for a file in directory B with same number
set -- "$useNamesFromDir"/"${f_num}"_*.*
[[ $1 && -e $1 ]] || {
echo "Could not find file number $f_num in $dirB" >&2
continue
}
(( $# > 1 )) && {
# there's more than one file with the same number; write an error
echo "Found more than one file with number $f_num in $dirB" >&2
printf ' - %q\n' "$#" >&2
continue
}
# extract the parts of our destination filename we want to keep
destName=${1##*/} # remove everything up to the last /
destName=${destName%.*} # and past the last .
# write the command we would run to stdout
printf '%q ' mv "$f" "$forFilesFromDir/$destName.$f_ext"; printf '\n'
## or uncomment this to actually run the command
# mv "$f" "$forFilesFromDir/$destName.$f_ext"
done
}
Now, how would we test this?
mkdir -p A B
touch A/00{1,2,3}_file.xyz B/00{1,2,3}_FILE_somerandomtext.zyx
renameFromDir A B
Given that, the output is:
mv B/001_FILE_somerandomtext.zyx B/001_file.zyx
mv B/002_FILE_somerandomtext.zyx B/002_file.zyx
mv B/003_FILE_somerandomtext.zyx B/003_file.zyx

Answer 2

Sorry if this isn't helpful, but I had fun writing it.
This renames items in folder B to the names in folder A, preserving the extension of B.
A_DIR="./A"
A_FILE_EXT=".xyz"
B_DIR="./B"
B_FILE_EXT=".zyx"
FILES_IN_A=`find $A_DIR -type f -name *$A_FILE_EXT`
FILES_IN_B=`find $B_DIR -type f -name *$B_FILE_EXT`
for A_FILE in $FILES_IN_A
do
A_BASE_FILE=`basename $A_FILE`
A_FILE_NUMBER=(${A_BASE_FILE//_/ })
A_FILE_WITHOUT_EXTENSION=(${A_BASE_FILE//./ })
for B_FILE in $FILES_IN_B
do
B_BASE_FILE=`basename $B_FILE`
B_FILE_NUMBER=(${B_BASE_FILE//_/ })
if [ ${A_FILE_NUMBER[0]} == ${B_FILE_NUMBER[0]} ]; then
mv $B_FILE $B_DIR/$A_FILE_WITHOUT_EXTENSION$B_FILE_EXT
break
fi
done
done