How can I stop my script to overwrite existing files - linux

I am learning bash since 6 days I think I got some of the basics.
Anyway, for the wallpapers downloaded from Variety I've written two scripts. One of them moves downloaded photos older than 12 days to a folder and renames them all as "Aday 1,2,3..." and the other lets me select these and moves them to another folder and removes photos I didn't select. 1st script works just as I intended, my question is about the other
I think I should write the script down to better explain my problem
Script:
#!/bin/bash
#Move victors of 'Seçme-Eleme' to 'Kazananlar'
cd /home/eurydice/Bulunur\ Bir\ Şeyler/Dosyamsılar/Seçme-Eleme
echo "Select victors"
read vct
for i in $vct; do
mv -i "Aday $i.png" /home/eurydice/"Bulunur Bir Şeyler"/Dosyamsılar/Kazananlar/"Bahar $RANDOM.png" ;
mv -i "Aday $i.jpg" /home/eurydice/"Bulunur Bir Şeyler"/Dosyamsılar/Kazananlar/"Bahar $RANDOM.jpg" ;
done
#Now let's remove the rest
rm /home/eurydice/Bulunur\ Bir\ Şeyler/Dosyamsılar/Seçme-Eleme/*
In this script I originally intended to define another variable (let's call this "n") and so did I with copying and changing the variable from the first script. It was something like that
for i in $vct; do
n=1
mv "Aday $i.png" /home/eurydice/"Bulunur Bir Şeyler"/Dosyamsılar/Kazananlar/"Bahar $n.png" ;
mv "Aday $i.jpg" /home/eurydice/"Bulunur Bir Şeyler"/Dosyamsılar/Kazananlar/"Bahar $n.jpg" ;
n=$((n+1))
done
When I do that for the first time the script worked just as I intended. However, in my 2nd test run this script overwrote the files that already existed. I mean, for example in 1st run i had 5 files whose names are "Bahar 1,2,3,4,5" and the 2nd time I chose 3 files to add. I wanted their names to be "Bahar 6,7,8" but instead, my script made them the new 1,2 and 3. I tried many solutions and when I couldn't fix that I just assigned random numbers to them.
Is there a way to make this script work as I intended?

This command finds the biggest file name number amongst files in current directory. If no file is found, biggest number is assigned to 0.
biggest_number=$(ls -1 | sed -n 's/^[^0-9]*\([0-9]\+\)\(\.[a-zA-Z]\+\)\?$/\1/p' | sort -r -g | head -n 1)
[[ ! -z "$biggest_number" ]] || biggest_number=0
The regex in sed command assumes that there is no digit in filenames before the trailing number intended for increment.
As soon as you have found the biggest number, you can use it to start your loop to prevent overwrites.
n=$((biggest_number+1))

Related

Change file's name using command line arguments Bash [duplicate]

This question already has answers here:
Change file's numbers Bash
(2 answers)
Closed 2 years ago.
I need to implement a script (duplq.sh) that would rename all the text files existing in the current directory using the command line arguments. So if the command duplq.sh pic 0 3 was executed, it would do the following transformation:
pic0.txt will have to be renamed pic3.txt
pic1.txt to pic4.txt
pic2.txt to pic5.txt
pic3.txt to pic6.txt
etc…
So the first argument is always the name of a file the second and the third always a positive digit.
I also need to make sure that when I execute my script, the first renaming (pic0.txt to pic3.txt), does not erase the existing pic3.txt file in the current directory.
Here's what i did so far :
#!/bin/bash
name="$1"
i="$2"
j="$3"
for file in $name*
do
echo $file
find /var/log -name 'name[$i]' | sed -e 's/$i/$j/g'
i=$(($i+1))
j=$(($j+1))
done
But the find command does not seem to work. Do you have other solutions ?
The problem you're trying to solve is actually somewhat tricky, and I don't think you've fully thought it through. For instance, what's the difference between duplq.sh pic 0 3 and duplq.sh pic 2 5 -- it looks like both should just add 3 to the number, or would the second skip "pic0.txt" and "pic1.txt"? What effect would either one have on files named "pic", "pic.txt", "picture.txt", "picture2.txt", "pic2-2.txt", or "pic999.txt".
There are also a bunch of basic mistakes in the script you have so far:
You should (almost) always put variable references in double-qotes, to avoid unexpected word-splitting and wildcard expansion. So, for example, use echo "$file" instead of echo $file. In for file in $name*, you should put double-quotes around the variable but not the *, because you want that to be treated as a wildcard. Hence, the correct version is for file in "$name"*
Don't put variable references in single-quotes, they aren't expanded there. So in the find and sed commands, you aren't passing the variables' values, you're passing literal dollar signs followed by letters. Again, use double-quotes. Also, you don't have a "$" before "name", so it won't be treated as a variable even in double-quotes.
But the find and sed commands don't do what you want anyway. Consider find /var/log -name "name[1]" -- that looks for files named "name1", not "name1" + some extension. And it looks in the current directory and all subdirectories, which I'm pretty sure you don't want. And the "1" ("$i") may not be the number in the current filename. Suppose there are files named "pic0.jpg", "pic0.png", and "pic0.txt" -- on the first iteration, the loop might find all three with a pattern like "pic0*", then on the second and third iterations try to find "pic1*" and "pic2*, which don't exist. On the other hand, suppose there are files named "pic0.txt", "pic5.txt", and "pic8.txt" -- again, it might look for "pic0*" (ok), then "pic1*" (not found), and then "pic2*" (ditto).
Also, if you get to multi-digit numbers, the pattern "name[10]" will match "file0" and "file1", but not "file10". I don't know why you added the brackets there, but they don't do anything you'd want.
You already have the files being listed one at a time in the $file variable, searching again with different criteria just adds confusion.
Also, at no point in the script do you actually rename anything. The find | sed line will (if it works) print the new name for the file, but not actually rename it.
BTW, when you do use the mv command, use either mv -n or mv -i to keep it from silently and irretrievably overwriting files if/when a name conflict occurs.
To prevent overwriting when incrementing file numbers, you need to do the renames in reverse numeric order (i.e. rename "pic3.txt" to "pic6.txt" before renaming "pic0.txt" to "pic3.txt"). This is especially tricky because if you just sort filenames in reverse alphabetic order, you'll get "pic7.txt" before "pic10.txt". But you can't do a numeric sort without removing the "pic" and ".txt" parts first.
IMO this is actually the trickiest problem to be solved in order to get this script to work right. It might be simplest to specify the largest index number as one of the arguments, and have it start there and count down to 0 (looping over numbers rather than files), and then for each number iterate over matching files (e.g. "pic0.jpg", "pic0.png", and "pic0.txt").
So I assume that 0 3 is just a measurement for the difference of old num and new num and equivalent to 1 4 or 100 103.
To avoid overwriting existing files, create a new temp dir, move all affected files there, and move all of them back in the end.
#/bin/bash
#
# duplq.sh pic 0 3
base="$1"
delta=$(( $3 - $2 ))
# echo delta $delta
target=$(mktemp -d)
echo $target
# /tmp/tmp.7uXD2GzqAb
add () {
f="$1"
b="$2"
d=$3
num=${f#./${b}}
# echo -e "file: $f \tnum: $num \tnum + d: $((num + d))" ;
echo -e "$((num + d))" ;
}
for f in $(find -maxdepth 1 -type f -regex ".*/${base}[0-9]+")
do
newnum=$(add "$f" "${base}" $delta)
echo mv "$f" "$target/${base}$newnum"
done
# exit
echo mv $target/${base}* .
First I tried to just use bash syntax, to check, whether removal of the prefix (pic) results in just digits remaining. I also didn't use the extension .txt - this is left as an exercise for the reader. From the question it is unclear - it is never explicitly told, that all files share the same extension, but all files in the example do.
With the -regex ".*/${base}[0-9]+") in find, the values are guaranteed to be just digits.
num=${f#./${b}}
removes from file f the base ("pic"). Delta d is added.
Instead of really moving, I just echoed the mv-command.
#TODO: Implement the file name extension conservation.
And 2 other pitfalls came to my mind: If you have 3 files pic0, pic00 and pic000 they all will be renamed to pic3. And pic08 will be cut into pic and 08, 08 will then be tried to be read as octal number (or 09 or 012129 and so on) and lead to an error.
One way to solve this issue is, that you prepend the extracted number (001 or 018) with a "1", then add 3, and remove the leading 1:
001 1001 1004 004
018 1018 1021 021
but this clever solution leads to new problems:
999 1999 2002 002?
So a leading 1 has to be cut off, a leading 2 has to be reduced by 1. But now, if the delta is bigger, let's say 300:
018 1018 1318 318
918 1918 2218 1218
Well - that seems to be working.

Linux script variables to SCP and delete files

I am looking to set up a script to do the following:
1st: SCP a directory on the first day of month to another server
2nd: Delete the directory after successful transfer
The directory I need to move will always have a different name, and the lowest numbered one is always the one that needs to move:
2018/files/02/
2018/files/03/
So what im looking to write up is something like:
scp /2018/files/% user#host:/backups/2018/files/
{where % = lowest num} &&
rm -rf /2018/files/%
{where % = lowest num} &&
exit
Thanks for any advice
If you are open to using Ruby, you could accomplish it with something like this:
def file_number(filespec)
filespect.split('/').last.to_i
end
directories = Dir['/2018/files'].select { |f| File.directory?(f) }
sorted_dirs = directories.sort_by do |dir1, dir2|
file_number(dir1) <=> file_number(dir1)
end
dir_to_copy = sorted_dirs.first
destination_dir = File.join('/', 'backups', dir_to_copy)
`scp #{dir_to_copy} user#host:#{destination_dir}`
`rm -rf #{dir_to_copy}`
I have not tested this, but if you have any problems, let me know what they are and I can work through it with you.
While using shell scripting eliminates the need for the Ruby interpreter, to me the code is not nearly as straightforward.
In very large directory lists (maybe 10,000's?) the sort might be intolerably slow, and another method would be needed to optimize for speed.
I would caution you against doing an unconditional rm -rf after the backup -- that seems really risky to me.
The big challenge here is to actually find the right files to copy, and shudder, delete. So let us call that step 0.
Let's start with some boiler plate
sourceD=/2018/files/
targetD=/backups/2018/files/
And a little assertion, which bails out from the script if $1 does not equate to a directory.
assert_directory() { (cd ${1:?directory name}) || exit; }
step 0: Identify directory:
assert_directory $sourceD
to_be_archived=$(
# source must be two characters, hence "??"
# source must a directory, hence trailing "/"
# set -- sorts its arguments
# First match must be our source
set -- $sourceD/??/ &&
assert_directory "$1"
echo ${1:?nothing found}
) || exit
This is only a couple of lines of condensed code. Note that this may
cause trouble if you (accidentally) run this multiple times in a row.
Step 1, Copy files now appears to be the easy part.
scp -r ${to_be_archived:?} user#host:${targetD:?}
This is a simple method for copying files, but also slow and risky.
Lookup rsync over ssh for alternatives.
Step 2, Remove
The rm -fr line will do the job, but I won't include that here.
We are missing an essential step, as we need to make sure that our
files have arrived safely. Again, rsync has options for that.
In summary:
assert_directory() { (cd ${1:?directory name}) || exit; }
assert_directory $sourceD
to_be_archived=$(
set -- $sourceD/??/ &&
assert_directory "$1"
echo ${1:?nothing found}
) || exit
This will give you the first two-character name directory (if one exists) in sourceD or abort the running script. It will break if $sourceD contains spaces.

One liner to append a file into another file but only if it hasn't already been added

I have an automated process that has a number of lines like the following pattern:
sudo cat /some/path/to/a/file >> /some/other/file
I'd like to transform that into a one liner that will only append to /some/other/file if /some/path/to/a/file has not already been added.
Edit
It's clear I need some examples here.
example 1: Updating a .bashrc script for a specific login
example 2: Creating a .screenrc for different logins
example 3: Appending to the end of a /etc/ config file
Some other caveats. The text is going to be added in a block (>>). Consequently, it should be relatively straight forward to see if the entire code block is added or not near the end of a file. I am trying to come up with a simple method for determining whether or not the file has already been appended to the original.
Thanks!
Example python script...
def check_for_appended(new_file, original_file):
""" Checks original_file to see if it has the contents of new_file """
new_lines = reversed(new_file.split("\n"))
original_lines = reversed(original_file.split("\n"))
appended = None
for new_line, orig_line in zip(new_lines, original_lines):
if new_line != orig_line:
appended = False
break
else:
appended = True
return appended
Maybe this will get you started - this GNU awk script:
gawk -v RS='^$' 'NR==FNR{f1=$0;next} {print (index($0,f1) ? "present" : "absent")}' file1 file2
will tell you if the contents of "file1" are present in "file2". It cannot tell you why, e.g. because you previously concatenated file1 onto the end of file2.
Is that all you need? If not update your question to clarify/explain.
Here's a technique to see if a file contains another file
contains_file_in_file() {
local small=$1
local big=$2
awk -v RS="" '{small=$0; getline; exit !index($0, small)}' "$small" "$big"
}
if ! contains_file_in_file /some/path/to/a/file /some/other/file; then
sudo cat /some/path/to/a/file >> /some/other/file
fi
EDIT: Op just told me in the comments that the files he wants to concatenate are bash scripts -- this brings us back to the good ole C preprocessor include guard tactics:
prepend every file with
if [ -z "$__<filename>__" ]; then __<filename>__=1; else
(of course replacing <filename> with the name of the file) and at the end
fi
this way, you surround the script in each file with a test for something that's only true once.
Does this work for you?
sudo (set -o noclobber; date > /tmp/testfile)
noclobber prevents overwriting an existing file.
I think it doesn't, since you wrote you want to append something but this technique might help.
When the appending all occurs in one script, then use a flag:
if [ -z "${appended_the_file}" ]; then
cat /some/path/to/a/file >> /some/other/file
appended_the_file="Yes I have done it except for permission/right issues"
fi
I would continue into writing a function appendOnce { .. }, with the content above. If you really want an ugly oneliner (ugly: pain for the eye and colleague):
test -z "${ugly}" && cat /some/path/to/a/file >> /some/other/file && ugly="dirt"
Combining this with sudo:
test -z "${ugly}" && sudo "cat /some/path/to/a/file >> /some/other/file" && ugly="dirt"
It appears that what you want is a collection of script segments which can be run as a unit. Your approach -- making them into a single file -- is hard to maintain and subject to a variety of race conditions, making its implementation tricky.
A far simpler approach, similar to that used by most modern Linux distributions, is to create a directory of scripts, say ~/.bashrc.d and keep each chunk as an individual file in that directory.
The driver (which replaces the concatenation of all those files) just runs the scripts in the directory one at a time:
if [[ -d ~/.bashrc.d ]]; then
for f in ~/.bashrc.d/*; do
if [[ -f "$f" ]]; then
source "$f"
fi
done
fi
To add a file from a skeleton directory, just make a new symlink.
add_fragment() {
if [[ -f "$FRAGMENT_SKELETON/$1" ]]; then
# The following will silently fail if the symlink already
# exists. If you wanted to report that, you could add || echo...
ln -s "$FRAGMENT_SKELETON/$1" "~/.bashrc.d/$1" 2>>/dev/null
else
echo "Not a valid fragment name: '$1'"
exit 1
fi
}
Of course, it is possible to effectively index the files by contents rather than by name. But in most cases, indexing by name will work better, because it is robust against editing the script fragment. If you used content checks (md5sum, for example), you would run the risk of having an old and a new version of the same fragment, both active, and without an obvious way to remove the old one.
But it should be straight-forward to adapt the above structure to whatever requirements and constraints you might have.
For example, if symlinks are not possible (because the skeleton and the instance do not share a filesystem, for example), then you can copy the files instead. You might want to avoid the copy if the file is already present and has the same content, but that's just for efficiency and it might not be very important if the script fragments are small. Alternatively, you could use rsync to keep the skeleton and the instance(s) in sync with each other; that would be a very reliable and low-maintenance solution.

script or command to change the starting index number of a set of sequentially numbered files

i have a set of files named img1.png , img2.png ,...img10.png,.. and so on. what i want to achieve is renaming these files so that the starting index is increased by 30 such that the files become img31.png, img32.png,.....img40.png,....and so on. Is this possible using the "rename" command? or is a script required? in either case how do i do this?
related - for this to work do i have to first rename the files to img001.png, img002.png, ...img010.png , and so on? how is this to be done, if required?
add 30 to the numbers in each filename
rename 's/(\d+)/$1+30/e' *png
rename to be 3 digits long
rename 's/(\d+)/sprintf("%03d",$1)/e' *png
See perldoc perlre http://perldoc.perl.org/perlre.html for details of how this works, rename is a perl program
LOCATION=/my/image/directory #change this to your location
for file in $(ls -1 ${LOCATION})
do
ind=$(echo ${file}|cut -c 4-|cut -d"." -f1)
(( newind=${ind}+30 ))
mv ${LOCATION}/${file} ${LOCATION}/img${newind}.png
done
I am sure there is much more elegant way of doing this on one line using likes of awk/sed/perl etc, but this shows you the logic behind it.
Hope it helps

Linux, re-name image file to create sequential list of files

I'm finding it difficult to word my question in a way I can search for the answer, my problem is as follows.....
I have a webcam that takes a photo every 2mins and saves as a numbered file, the first photo is taken at 0000hrs and is named image001.jpg, at 0002hrs image002.jpg and so on. At 2359hrs all the photos are turned in to 24hr time lapse video and saved as daily_video.mov. At 0000hrs (of the next day) the old image001.jpg is over written and the whole process repeated including generation of a new daily_video.mov.
This is all working fine with the webcam doing the file naming and overwriting, and a cron job running fffmpeg once a day to make the video.
What I want to do now is make a time lapse video over say a month by copying every 30th file from the days images to a new folder and naming in a sequential order. ie.
Day 1; image030.jpg, image060.jpg, etc... are renamed to Archive001.jpg, Archive002.jpg,etc...
But on day 2; image030.jpg, image060.jpg etc... Will need to be named to Archive025.jpg, Archive026.jpg etc.. and repeat untill the end of the month copying files from the day to a sequentially increasing in name list of files to use at the end of month, where the process can be repeated.
Does that make sense?!!
You could use a bash script like the following. Just call it at 2359hrs.
Remeber to make it executable using chmod +x myScript
I did not rename to Archive00X.jpg, but by adding the current date, they will be in proper alphabetical order.
example output:
cp files/image000.jpg >> archive/image_2012-08-29_000.jpg
cp files/image030.jpg >> archive/image_2012-08-29_030.jpg
....
adapt pSource and pDest to your paths (preferrably absolute paths)
adapt offset and maxnum to your needs. If maxnum is too big it will tell you some files are missing, but otherwise work properly.
Remove the echo lines if they disturb you ;)
Code:
#!/bin/bash
pSource="files"
pDest="archive"
offset=30
maxnum=721
curdate=`date "+%F"`
function rename_stuff()
{
myvar=0
while [ $myvar -lt $maxnum ]
do
forg=`printf image%03d.jpg ${myvar}`
fnew=`printf image_%s_%03d.jpg ${curdate} ${myvar}`
forg="$pSource/$forg"
fnew="$pDest/$fnew"
if [ -f "$forg" ]; then
echo "cp $forg >> $fnew"
cp "$forg" "$fnew"
else
echo "missing file $forg"
fi
myvar=$(( $myvar + $offset ))
done
}
rename_stuff

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