Getting relative paths in BASH - bash

I already searched for this, but I guess there was no great demand on working with paths.
So I'm trying two write a bash script to convert my music collection using tta and cue files.
My directory structure is as following: /Volumes/External/Music/Just/Some/Dirs/Album.tta for the tta files and /Volumes/External/Cuesheets/Just/Some/Dirs/Album.cue for cue sheets.
My current approach is setting /Volumes/External as "root_dir" and get the relative path of the album.tta file to $ROOT_DIR/Music (in this case this would be Just/Some/Dirs/Album.tta), then add this result to $ROOT_DIR/Cuesheets and change the suffix from .tta to .cue.
My current problem is, that dirname returns paths as they are, which means /Volumes/External/Music/Just/Some/Dirs does not get converted to ./Just/Some/Dirs/ when my current folder is $ROOT_DIR/Music and the absolute path was given.
Add://Here is the script if anybody has similar problems:
#!/bin/bash
ROOT_DIR=/Volumes/External
BASE="$1"
if [ ! -f "$BASE" ]
then
echo "Not a file"
exit 1
fi
if [ -n "$2" ]
then
OUTPUT_DIR="$HOME/tmp"
else
OUTPUT_DIR="$2"
fi
mkfdir -p "$OUTPUT_DIR" || exit 1
BASE=${BASE#"$ROOT_DIR/Music/"}
BASE=${BASE%.*}
TTA_FILE="$ROOT_DIR/Music/$BASE.tta"
CUE_FILE="$ROOT_DIR/Cuesheets/$BASE.cue"
shntool split -f "${CUE_FILE}" -o aiff -t "%n %t" -d "${OUTPUT_DIR}" "${TTA_FILE}"
exit 0

If your Cuesheets dir is always in the same directory as your Music, you can just remove root_dir from the path, and what is left is the relative path. If you have the path to your album.tta in album_path (album_path=/Volumes/External/Music/Just/Some/Dirs/Album.tta) and your root_dir set(root_dir=/Volumes/External), just do ${album_path#$root_dir}. This trims root_dir from the front of album_path, so you are left with album_path=Just/Some/Dirs/Album.tta.
See bash docs for more information on bash string manipulation
EDIT:// Changed ${$album_path#$root_dir} to ${album_path#$root_dir}

Okay so I've tackled this a couple of ways in the past. I don't recommend screwing with paths and pwd environment variables, I've seen some catastrophic events because of it.
Here's what I would do
CURRENTDIR=/Volumes/External/Music # make sure you check the existence in your script
...
SEDVAL=$(echo $CURRENTDIR | sed s/'\/'/'\\\/'/g)
#run your loops for iterating through files
for a in $(find ./ -name \*ogg); do
FILE=`echo $a | sed s/$SEDVAL/./g` # strip the initial directory and replace it with .
convert_file $FILE # whatever action to be performed
done
If this is something you might do frequently I would actually just write a separate script just for this.

Related

mv command and rename not working on multiple flies

Below is a bash script to move files around and rename them. The problem is it doesn't work when there is more than one file in the directory. I'm assuming because the last parameter in the mv command is a file. Any suggestions?
'#!/bin/bash'
'INPUTDIR="/home/southern-uniontn/S001007420"'
'OUTPUTDIR="/mnt/edi-06/southern-uniontn/flats-in"'
'BACKUPDIR="/backup/southern-uniontn/S001007420"'
YEAR=`date +%Y`
MONTH=`date +%m`
DAY=`date +%d`
HOUR=`date +%H`
MINUTE=`date +%M`
######## Do some error checking #########
# Does backup dir exist?
if [ ! -d $BACKUPDIR/$YEAR ]
then
mkdir $BACKUPDIR/$YEAR
fi
if [ ! -d $BACKUPDIR/$YEAR/$MONTH ]
then
mkdir $BACKUPDIR/$YEAR/$MONTH
fi
if [ ! -d $BACKUPDIR/$YEAR/$MONTH/$DAY ]
then
mkdir $BACKUPDIR/$YEAR/$MONTH/$DAY
fi
if [[ $(find $INPUTDIR -type f | wc -l) -gt 0 ]];
then
###### Rename the file, move it to Backup, then copy to the Output Directory #####
for f in $INPUTDIR/*
do
echo "`date` - Move recurring txt flat file to BackupDir for Union TN from Southern"
mv $INPUTDIR/* $BACKUPDIR/$YEAR/$MONTH/$DAY/UnionTN-S001007420-$YEAR$MONTH$DAY-$HOUR$MINUTE.txt
sleep 2
echo "`date` - Copy backup file to the Union TN Output Directory"
cp $BACKUPDIR/$YEAR/$MONTH/$DAY/UnionTN-S001007420-$YEAR$MONTH$DAY-$HOUR$MINUTE.txt $OUTPUTDIR/
done;
fi
Some notes:
Get out of the habit of using ALLCAPS variable names, leave those as reserved
by the shell. One day you'll write PATH=something and then wonder
why your script is
broken.
mkdir -p can create parent directories, and will not error if the dir already exists
store the filenames in an array. Then the shell does not have to duplicate
the work, and you don't need to count how many there are: if there are no
files, the loop has zero iterations
if you want to keep the same directory hierarchy in the outputdir,
you need to do that by hand.
use read to get the date parts
with bash v4.2+, printf can be used instead of calling out to date
use magic value "-1" to mean "now".
printf '%(%Y-%m-%d)T\n' -1 prints "2021-10-25" (as of the day I write this)
This is, I think, what you want:
#!/bin/bash
inputdir='/home/southern-uniontn/S001007420'
outputdir='/mnt/edi-06/southern-uniontn/flats-in'
backupdir='/backup/southern-uniontn/S001007420'
read year month day hour minute < <(printf '%(%Y %m %d %H %M)T\n' -1)
# create backup dirs if not exists
date_dir="$year/$month/$day"
mkdir -p "$backupdir/$date_dir"
mkdir -p "$outputdir/$date_dir"
mapfile -t files < <(find $inputdir -type f)
for f in "${files[#]}"
do
###### Rename the file, move it to Backup, then copy to the Output Directory #####
backup_file="UnionTN-S001007420-$year$month$day-$hour$minute.txt"
printf '%(%c)T - Move recurring txt flat file to backupdir for Union TN from Southern\n' -1
mv "$f" "$backupdir/$date_dir/$backup_file"
printf '%(%c)T - Copy backup file to the Union TN Output Directory\n' -1
cp "$backupdir/$date_dir/$backup_file" "$outputdir/$date_dir/$backup_file"
done
When using a glob with mv, the target must be an existing directory, and all matching files will be moved inside that directory.
In your case,
mv $INPUTDIR/* $BACKUPDIR/$YEAR/$MONTH/$DAY/UnionTN-S001007420-$YEAR$MONTH$DAY-$HOUR$MINUTE.txt
tells mv to move all file inside the $INPUTDIR/* directory to a directory named $BACKUPDIR/$YEAR/$MONTH/$DAY/UnionTN-S001007420-$YEAR$MONTH$DAY-$HOUR$MINUTE.txt.
I'm not sure what you're trying to do, but I hope this help.
Some more advice you could use:
Don't put the shebang (the first line beginning with "#") and the first three variable declarations inside single-quotes.
Some argue it is more portable and better to write /usr/bin/env bash instead of /bin/bash in the shebang
if [ CONDITION ] /then ACTION /fi statements can be simplified by writing [ CONDITION ] && ACTION
You reduce your likely hood of encountering unexpected behaviour when double-quoting your strings and variable (i.e. write "${year}/${month}/" instead of $year/$month.
No need to call mkdir a, followed by mkidr a/b, then mkdir a/b/c and so on, you can just call mkdir -p a/b/c. The p flag tells mkdir to create parent directories if they don't already exist.
It is unnecessary to validate the existence of a directory before calling mkdir since mkdir already validates that for you.
As pointed out by commenters, all-caps variables are conventions for special POSIX related variables. You should use another type of casing.
You could use date to do the formatting for you: date +%Y/%m/%d will print 2021/10/25
Strings without interpolation can have single-quotes.
(Optional, prevent undesired behaviors) Put set -e at the beginning of your scripts, after the shebang, to tell bash to halt if an error is encountered
And finally, use man <command_name> for built-in documentation!

Change date modified of multiple folders to match that of their most recently modified file

I've been using the following shell bin/bash script as an app which I can drop a folder on, and it will update the date modified of the folder to match the most recently modified file in that folder.
for f in each "$#"
do
echo "$f"
done
$HOME/setMod "$#"
This gets the folder name, and then passes it to this setMod script in my home folder.
#!/bin/bash
# Check that exactly one parameter has been specified - the directory
if [ $# -eq 1 ]; then
# Go to that directory or give up and die
cd "$1" || exit 1
# Get name of newest file
newest=$(stat -f "%m:%N" * | sort -rn | head -1 | cut -f2 -d:)
# Set modification date of folder to match
touch -r "$newest" .
fi
However, if I drop more than one folder on it at a time, it won't work, and I can't figure out how to make it work with multiple folders at once.
Also, I learned from Apple Support that the reason so many of my folders keep getting the mod date updated is due to some Time Machine-related process, despite the fact I haven't touched some of them in years. If anyone knows of a way to prevent this from happening, or to somehow automatically periodically update the date modified of folders to match the date/time of the most-recently-modified file in them, that would save me from having to run this step manually pretty regularly.
The setMod script current accepts only one parameter.
You could either make it accept many parameters and loop over them,
or you could make the calling script use a loop.
I take the second option, because the caller script has some mistakes and weak points. Here it is corrected and extended for your purpose:
for dir; do
echo "$dir"
"$HOME"/setMod "$dir"
done
Or to make setMod accept multiple parameters:
#!/bin/bash
setMod() {
cd "$1" || return 1
# Get name of newest file
newest=$(stat -f "%m:%N" * | sort -rn | head -1 | cut -f2 -d:)
# Set modification date of folder to match
touch -r "$newest" .
}
for dir; do
if [ ! -d "$dir" ]; then
echo not a directory, skipping: $dir
continue
fi
(setMod "$dir")
done
Notes:
for dir; do is equivalent to for dir in "$#"; do
The parentheses around (setMod "$dir") make it run in a sub-shell, so that the script itself doesn't change the working directory, the effect of the cd operation is limited to the sub-shell within (...)

How to set a Directory as an Argument in Bash

I am having trouble finding out how to set a directory as an argument in bash.
The directory I am trying to have as an argument is /home/rrodriguez/Documents/one.
Anywhere I try to look for an answer I see examples like dir = $1 but I cant seem to find an explanation of what this means or how to set it up so that it references my specific file location. Could anyone show me how to set up my variable for my path directory?
Adding my code for a better understanding of what im trying to do:
#!bin/bash
$1 == 'home/rrodriguez/Documents/one/'
dir = $1
touch -c $dir/*
ls -la $dir
wc$dir/*
Consider:
#!bin/bash
dir=$1
touch -c "$dir"/*
ls -la "$dir"
This script takes one argument, a directory name, and touches files in that directory and then displays a directory listing. You can run it via:
bash script.sh 'home/rrodriguez/Documents/one/'
Since home/rrodriguez/Documents/one/ is the first argument to the script, it is assigned to $1 in the script.
Notes
In shell, never put spaces on either side of the = in an assignment.
I omitted the line wc$dir/* because it wasn't clear to me what the purpose of it was.
I put double-quotes around $dir to prevent the shell from, among other things, performing word-splitting. This would matter if dir contains spaces.

A simple mv command in a BASH script

The aim of my script:
look at all the files in a directory ($Home/Music/TEST) and its sub-directories (they are music files)
find out what music genre each file belongs to
if the genre is Heavy, then move the file to another directory ($Home/Music/Output)
This is what I have:
#!/bin/bash
cd Music/TEST
for files in *
do
if [ -f "$files" ];then
# use mminfo to get the track info
genre=`mminfo "$files"|grep genre|awk -F: '{print $2}'|sed 's/^ *//g'|sed 's/[^a-zA-Z0-9\ \-\_]//g'`
if [ $genre = Heavy ] ;then
mv "$files" "~/Music/Output/$files"
fi
fi
done
Please tell me how to write the mv command. Everything I have tried has failed. I get errors like this:
mv: cannot move ‘3rd Eye Landslide.mp3’ to ‘/Music/Output/3rd Eye Landslide.mp3’: No such file or directory
Please don't think I wrote that mminfo line - that's just copied from good old Google search. It's way beyond me.
Your second argument to mv appears to be "~/Music/Output/$files"
If the ~ is meant to signify your home directory, you should use $HOME instead, like:
mv "$files" "$HOME/Music/Output/$files"
~ does not expand to $HOME when quoted.
By the look of it the problem occurs when you move the file to its destination.Please check that /Music/Output/ exits from your current directory.Alternatively use the absolute path to make it safe. Also it's a good idea not use space in the file-name.Hope this will helps.:)
Put this command before mv command should fix your problem.
mkdir -p ~/Music/Output

Recycle bin in bash problem

I need to make a recycle bin code using bash. Here is what I have done so far. My problem is that when I move a file with the same name into the trash folder it just overwrites the previous file. Can you give me any suggestions on how to approach this problem?
#!/bin/bash
mkdir -p "$HOME/Trash"
if [ $1 = -restore ]; then
while read file; do
mv $HOME/Trash/$2 /$file
done < try.txt
else
if [ $1 = -restoreall ]; then
mv $HOME/Trash/* /$PWD
else
if [ $1 = -empty ]; then
rm -rfv /$HOME/Trash/*
else
mv $PWD/"$1"/$HOME/Trash
echo -n "$PWD" >> /$HOME/Bash/try
fi
fi
fi
You could append the timestamp of the time of deletion to the filename in your Trash folder. Upon restore, you could strip this off again.
To add a timestamp to your file, use something like this:
DT=$(date +'%Y%m%d-%H%M%S')
mv $PWD/"$1" "/$HOME/Trash/${1}.${DT}"
This will, e.g., create a file like initrd.img-2.6.28-11-generic.20110615-140159 when moving initrd.img-2.6.28-11-generic.
To get the original filename, strip everything starting from the last dot, like with:
NAME_WITHOUT_TIMESTAMP=${file%.*-*}
The pattern is on the right side after the percentage char. (.* would also be enough to match.)
Take a look how trash-cli does it. It's written in Python and uses the same trash bin as desktop environments. Trash-cli is available at least in the big Linux distributions.
http://code.google.com/p/trash-cli/
Probably the easiest thing to do is simply add -i to the invocation of mv. That will prompt the user whether or not to replace. If you happen to have access to gnu cp (eg, on Linux), you could use cp --backup instead of mv.

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