[SOLVED] Re-arrange a string

GPGAgent · 06-09-2022, 05:02 PM

I have a file name like this

Code:

Book Title (author)

and I want to swap this around

Code:

(author) Book Title

I think awk should be able to do this, but I cannot figue out how to do it
Then I thought a bash scripy might do it, again not too sure what to do.

I have about 1,000 files to be processed.

If i could get the position of the brackets I could chop that out and then prepend it to the begining, well thats my plan for the bash script.

GPGAgent · 06-09-2022, 05:31 PM

Okay I can do this

Code:

jonke@charlie:~$ echo $x
abc murders (Agatha Christie).epub
jonke@charlie:~$ y=${x%(*}
jonke@charlie:~$ echo $y
abc murders
jonke@charlie:~$ z=${x:${#y}}
jonke@charlie:~$ echo $z
(Agatha Christie).epub
jonke@charlie:~$ a=${z%.*}
jonke@charlie:~$ echo $a
(Agatha Christie)
jonke@charlie:~$ echo $a $y
(Agatha Christie) abc murders

But there must be better more elegant way

syg00 · 06-09-2022, 07:35 PM

Quote:

Originally Posted by GPGAgent

But there must be better more elegant way

Several.
Filenames with whitespace in them will be the bane of your life - FWIW I change them all to underscore.

Mangling the string that represents the filename is merely the first step - you still need to feed it all to mv. Better option is to see if you have the perl version of rename - it can do the whole deal, for all files, in a single command with a little regex.

grail · 06-09-2022, 11:20 PM

You could use regex if you know the format is always the same:

Code:

x='abc murders (Agatha Christie).epub'
reg='([^(]+)(\([^)]+\))'

[[ "$x" =~ $reg ]] && echo done

echo "${BASH_REMATCH[1]}"
echo "${BASH_REMATCH[2]}"

or maybe an awk:

Code:

awk -F'[()]' '{print "title - ",$1;print "author - ",$2}' <<<'abc murders (Agatha Christie).epub'

rnturn · 06-09-2022, 11:23 PM

Quote:

Originally Posted by GPGAgent

I have a file name like this

Code:

Book Title (author)

and I want to swap this around

Code:

(author) Book Title

I think awk should be able to do this, but I cannot figue out how to do it
Then I thought a bash scripy might do it, again not too sure what to do.

The guts of something that receives each filename could use something like

Code:

IN="$*"
TITLE=$( echo ${IN} | cut -d'(' -f1 )
AUTHOR=$( echo ${IN} | cut -d'(' -f2 | cut -d')' -f1 )
OUT="(${AUTHOR}) ${TITLE}"

Using "$IN" and "$OUT", you can likely build a "mv" command to rename the files to the new format.

But... as someone pointed out, spaces in filenames will drive you crazy. I often run a script on the files or directory tree to replace spaces with underscores. Downside? Yes, Occasionally, I'll find that some of the files refer to the "spaced" version of other files and/or directories. Fixing those when encountered, though, seems easier than having to account for spaces in every single utility I have to write to deal with them. Maybe take this as an opportunity to make a new format like, say:

Code:

Author_Name--The_Title_of_the_Book    or
Author_Name:The_Title_of_The_Book

Turbocapitalist · 06-10-2022, 01:21 AM

Quote:

Originally Posted by syg00

Better option is to see if you have the perl version of rename - it can do the whole deal, for all files, in a single command with a little regex.

I, too, would turn to the perl version of rename since it can do both Perl regular expressions and perl expressions (scripting) in the transformation of the name:

Code:

rename -n -v 's/^(.*)\s+(\([^)]*\))\.epub/$2 $1/' *.epub

GPGAgent · 06-10-2022, 08:36 AM

Hi All, Plenty to check out here, many thnaks.

And yes white space is pain (PITA).

Perl looks a good bet, I don't know perl so this will teach me something new.

I'll leave this open for a bit and post my final solution when I have it and yes I do have a backup.

laters folks

allend · 06-10-2022, 08:51 AM

A bash solution is a little more verbose.

Code:

# For recursion
# topdirectory=$HOME/some/directory
# cd $topdirectory
# shopt -s globstar
# for f in **/*.epub; do
for f in *.epub; do
  [[ "$f" =~ ([^(]+) (\([^)]+\))(.*) ]] && echo mv "$f" "${BASH_REMATCH[2]} ${BASH_REMATCH[1]}${BASH_REMATCH[3]}"
done

Remove the 'echo' if happy.

PS - Damn this new code parsing stuff at LQ (It just swapped in a hyphen for tilde). "$f" =~ should read "$f" ="tilde character"

GPGAgent · 06-10-2022, 09:04 AM

Quote:

Originally Posted by allend

A bash solution is a little more verbose.

Code:

# For recursion
# topdirectory=$HOME/some/directory
# cd $topdirectory
# shopt -s globstar
# for f in **/*.epub; do
for f in *.epub; do
  [[ "$f" =~ ([^(]+) (\([^)]+\))(.*) ]] && echo mv "$f" "${BASH_REMATCH[2]} ${BASH_REMATCH[1]}${BASH_REMATCH[3]}"
done

Remove the 'echo' if happy.

PS - Damn this new code parsing stuff at LQ (It just swapped in a hyphen for tilde). "$f" =~ should read "$f" ="tilde character"

Perfect, many thanks

allend · 06-10-2022, 09:58 AM

Thanks go to @grail, who first introduced me to the power of BASH_REMATCH. I just fixed the space character handling.

boughtonp · 06-10-2022, 10:21 AM

Quote:

Originally Posted by allend

PS - Damn this new code parsing stuff at LQ (It just swapped in a hyphen for tilde). "$f" =~ should read "$f" ="tilde character"

Huh? Only hyphens in your post are after "shopt " and "PS "; the tildes are correct both inside and outside the code block.

GPGAgent · 06-10-2022, 10:36 AM

Quote:

Originally Posted by boughtonp

Huh? Only hyphens in your post are after "shopt " and "PS "; the tildes are correct both inside and outside the code block.

That's what I saw (thought)!

~
-

syg00 · 06-11-2022, 05:55 AM

There is the small issue of pre-existing target filenames tho' ...

GPGAgent · 06-12-2022, 07:51 AM

Quote:

Originally Posted by syg00

There is the small issue of pre-existing target filenames tho' ...

For this reason I'll copy the file with it's new name to a folder called PROCESSED