I'm looking for a good shell one liner to move or rename a file inside a directory, where the target and destination parent directories are the same, and different than the current working directory. For example, the thing I don't want to write:
$ mv /usr/share/nginx/html/app.xml /usr/share/nginx/html/index.html
How can I do this same thing without typing '/usr/share/nginx/html/' twice or using multiple commands (to switch directory, pushd, etc)?
You can use braces expansion:
$ mv /usr/share/nginx/html/{app.xml,index.html}
You can use a subshell:
(cd /usr/share/nginx/html; mv app.xml index.html)
Related
I'm new to linux and shell script in general. I'm using a distribution of Debian on the WSL (Windows Subsystem for Linux). I'm trying to write a very simple bash script that will do the following:
create a file in a directory (child-directory-a)
move to the directory it is in
move the file to another directory (child-directory-b)
move to that directory
move the file to the parent directory
This is what I have so far (trying to keep things extremely simple for now)
touch child-directory-a/test.txt
cd child-directory-a
mv child-directory-a/test.txt home/username/child-directory-b
The first two lines work, but I keep getting a 'no such directory exists' error with the last one. The directory exists and that is the correct path (checked with pwd). I have also tried using different paths (i.e. child-directory-b, username/child-directory-b etc.) but to no avail. I can't understand why it's not working.
I've looked around forums/documentation and it seems that these commands should work as they do in the command line, but I can't seem to do the same in the script.
If anyone could explain what I'm missing/not understanding that would be brilliant.
Thank you.
You could create the script like this:
#!/bin/bash
# Store both child directories on variables that can be loaded
# as environment variables.
CHILD_A=${CHILD_A:=/home/username/child-directory-a}
CHILD_B=${CHILD_B:=/home/username/child-directory-b}
# Create both child folders. If they already exist nothing will
# be done, and no error will be emitted.
mkdir -p $CHILD_A
mkdir -p $CHILD_B
# Create a file inside CHILD_A
touch $CHILD_A/test.txt
# Change directory into CHILD_A
cd $CHILD_A
# Move the file to CHILD_B
mv $CHILD_A/test.txt $CHILD_B/test.txt
# Move to CHILD_B
cd $CHILD_B
# Move the file to the parent folder
mv $CHILD_B/test.txt ../test.txt
Take into account the following:
We make sure that all the folders exists and are created.
Use variables to avoid typos, with the ability to load dynamic values from environment variables.
Use absolute paths to simplify the movement between folders.
Use relative paths to move files relatives to where we are.
Another command that might be of use is pwd. It will tell you the directory you are on.
with your second line, you change the current directory to child-directory-a
so, in your third line there is an error because there is no subdirectory child-directory-a into subdirectory child-directory-a
Your third line should be instead :
mv test.txt ../child-directory-b
The point #4 of your script should be:
cd ../child-directory-b
(before that command the current directory is home/username/child-directory-a and after this command it becomes home/username/child-directory-b)
Then the point #5 and final point of your script should be:
mv test.txt ..
NB: you can display the current directory at any line of your script by using the command pwd (print working directory) in your script, it that helps
#!/bin/sh
# Variables
WORKING_DIR="/home/username/example scripts"
FILE_NAME="test file.txt"
DIR_A="${WORKING_DIR}/child-directory-a"
DIR_B="${WORKING_DIR}/child-directory-b"
# create a file in a directory (child-directory-a)
touch "${DIR_A}/${FILE_NAME}"
# move to the directory it is in
cd "${DIR_A}"
# move the file to another directory (child-directory-b)
mv "${FILE_NAME}" "${DIR_B}/"
# move to that directory
cd "${DIR_B}"
# move the file to the parent directory
mv "${FILE_NAME}" ../
When I run mv * with no destination directory on a directory with say 10 files, I get an error as follows
root#tryit-apparent:~/test2# ls
file1.txt file10.txt file2.txt file3.txt file4.txt file5.txt file6.txt file7.txt file8.txt file9.txt
root#tryit-apparent:~/test2# mv *
mv: target 'file9.txt' is not a directory
When I run it on a directory with two files it overwrites the file with one just file.
root#tryit-apparent:~/test# ls
tempfile tempfile2
root#tryit-apparent:~/test# mv *
root#tryit-apparent:~/test# ls
tempfile2
I read the man pages but couldn't understand this behaviour. Would like to know what's causing this behavior and what's going on under the hood?
What other linux commands have such pitfalls and have destructive actions that are executed silently if the user is not aware of such behavior?
In Unix, unlike some other OSes, wildcards like * are expanded by the shell, before being passed to the command being run. So when you run mv * with tempfile and tempfile2 as the only files in the current directory, what the shell actually executes is mv tempfile tempfile2, which as normal will rename the first file over the second one, erasing the previous contents of tempfile2. The shell doesn't know or care that this command treats its last argument specially, and mv has no way of knowing that its two arguments came from a wildcard expansion. Hence the behavior you're seeing.
You can have similar issues even with more than two files. For instance, if you have files named tempfile1 through tempfile9 and a subdirectory named zyzzx, then mv * will move all your temp files into the zyzzx subdirectory.
Mostly, you just have to be aware that this is how wildcards work, and use caution with commands that treat one of their arguments specially (e.g. as a destination). cp is another one to watch out for, for the same reason. For interactive usage, you may want to get used to using the -i option to mv and cp, which asks for confirmation before overwriting files; or use an alias to make this the default.
Move is intented to move or rename a file or a directory, so you need a source and a destination.
If the path of the file is unchange then it becomes a rename operation.
If the path changes and the name remains the same it's a move.
You can do both by chaning the path and the name.
Man pages can be challenging to wrap your head around.
Googling can help: https://www.howtoforge.com/linux-mv-command/
Off the top of my head, you could do a cp operation followed by a rm to achieve similar results, but that's two steps, rather than one.
I'm trying to rename the script audience_segment_map.sh to audience_segment_map_dedupe.sh using the Linux command line.
I have tried using the mv and the rename commands but they're not having the desired effect:
mv user/local/dmp_job/audience_segment_map.sh user/local/dmp_job/audience_segment_map_deupe.sh
This returns the error
'audience_segment_map.sh' No such file or directory"
but when I use the ls command, the file clearly shows up.
How should I proceed?
Pointing to a path with and without leading / slashes are different (absolute versus relative, respectively). Unless you are in the root directory, most likely you want your command to look like
mv /user/local/dmp_job/audience_segment_map.sh /user/local/dmp_job/audience_segment_map_deupe.sh
where the path is pointing to /user/local/... instead of user/local/...
I have a set of folders like:
/path/to/group1/folder/number123
/path/to/group1/folder/number456
/path/to/group2/folder/number123
/path/to/group2/folder/number456
/path/to/group3/folder/number123
/path/to/group3/folder/number456
And I want to move folders that match /path/to/group*/folder/number123
to the base folder /path/toOther/ so that after the move it looks like:
/path/to/group1/folder/number456
/path/to/group2/folder/number456
/path/to/group3/folder/number456
/path/toOther/group1/folder/number123
/path/toOther/group2/folder/number123
/path/toOther/group3/folder/number123
Is there a way to do this with a move command and wild cards, or will it require more than a 1-liner?
If you don't mind writing a few lines:
cd /path/to
for f in group*/folder/number123
do
d="/path/toOther/${f%/*}"
mkdir -p "$d"
mv "$f" "$d/."
done
Of course you can combine the script into one line. (Or the bash will do this when you recall it with the Up key.)
I have a directory containing a set of subdirectories and files. I need to recursively copy all the content of this directory to all the subdirectories of another directory, also recursively.
How do I achieve this, preferably without using a script and only with the cp command?
You can write this in a script but you don't have to. Just write it line by line in the terminal:
# $TARGET is the directory containing subdirectories where you want to STORE the copies
# $SOURCE is the directory containing the subdirectories you want to COPY
for dir in $(ls $TARGET); do
cp -r $SOURCE/* $TARGET/$dir
done
Only uses cp and runs on both bash and zsh.
You can't. cp can copy multiple sources but will only copy to a single destination. You need to arrange to invoke cp multiple times - once per destination - for what you want to do; using, as you say, a loop or some other tool.
The first part of the command before the pipe instruct tar to create an archive of everything in the current directory and write it to standard output (the – in place of a file-name frequently indicates stdout).
tar cf - * | ( cd /target; tar xfp -)
The commands within parentheses cause the shell to change directory to the target directory and untar data from standard input. Since the cd and tar commands are contained within parentheses, their actions are performed together.
The -p option in the tar extraction command directs tar to preserve permission and ownership information, if possible given the user executing the command. If you are running the command as superuser, this option is turned on by default and can be omitted.
Also you can use the following command, but it seems to be quite slower than tar;
cp -a * /target