I'm looping through certain files (all files starting with MOVIE) in a folder with this bash script code:
for i in MY-FOLDER/MOVIE*
do
which works fine when there are files in the folder. But when there aren't any, it somehow goes on with one file which it thinks is named MY-FOLDER/MOVIE*.
How can I avoid it to enter the things after
do
if there aren't any files in the folder?
With the nullglob option.
$ shopt -s nullglob
$ for i in zzz* ; do echo "$i" ; done
$
for i in $(find MY-FOLDER/MOVIE -type f); do
echo $i
done
The find utility is one of the Swiss Army knives of linux. It starts at the directory you give it and finds all files in all subdirectories, according to the options you give it.
-type f will find only regular files (not directories).
As I wrote it, the command will find files in subdirectories as well; you can prevent that by adding -maxdepth 1
Edit, 8 years later (thanks for the comment, #tadman!)
You can avoid the loop altogether with
find . -type f -exec echo "{}" \;
This tells find to echo the name of each file by substituting its name for {}. The escaped semicolon is necessary to terminate the command that's passed to -exec.
for file in MY-FOLDER/MOVIE*
do
# Skip if not a file
test -f "$file" || continue
# Now you know it's a file.
...
done
Related
From the current directory I have multiple sub directories:
subdir1/
001myfile001A.txt
002myfile002A.txt
subdir2/
001myfile001B.txt
002myfile002B.txt
where I want to strip every character from the filenames before myfile so I end up with
subdir1/
myfile001A.txt
myfile002A.txt
subdir2/
myfile001B.txt
myfile002B.txt
I have some code to do this...
#!/bin/bash
for d in `find . -type d -maxdepth 1`; do
cd "$d"
for f in `find . "*.txt"`; do
mv "$f" "$(echo "$f" | sed -r 's/^.*myfile/myfile/')"
done
done
however the newly renamed files end up in the parent directory
i.e.
myfile001A.txt
myfile002A.txt
myfile001B.txt
myfile002B.txt
subdir1/
subdir2/
In which the sub-directories are now empty.
How do I alter my script to rename the files and keep them in their respective sub-directories? As you can see the first loop changes directory to the sub directory so not sure why the files end up getting sent up a directory...
Your script has multiple problems. In the first place, your outer find command doesn't do quite what you expect: it outputs not only each of the subdirectories, but also the search root, ., which is itself a directory. You could have discovered this by running the command manually, among other ways. You don't really need to use find for this, but supposing that you do use it, this would be better:
for d in $(find * -maxdepth 0 -type d); do
Moreover, . is the first result of your original find command, and your problems continue there. Your initial cd is without meaningful effect, because you're just changing to the same directory you're already in. The find command in the inner loop is rooted there, and descends into both subdirectories. The path information for each file you choose to rename is therefore stripped by sed, which is why the results end up in the initial working directory (./subdir1/001myfile001A.txt --> myfile001A.txt). By the time you process the subdirectories, there are no files left in them to rename.
But that's not all: the find command in your inner loop is incorrect. Because you do not specify an option before it, find interprets "*.txt" as designating a second search root, in addition to .. You presumably wanted to use -name "*.txt" to filter the find results; without it, find outputs the name of every file in the tree. Presumably you're suppressing or ignoring the error messages that result.
But supposing that your subdirectories have no subdirectories of their own, as shown, and that you aren't concerned with dotfiles, even this corrected version ...
for f in `find . -name "*.txt"`;
... is an awfully heavyweight way of saying this ...
for f in *.txt;
... or even this ...
for f in *?myfile*.txt;
... the latter of which will avoid attempts to rename any files whose names do not, in fact, change.
Furthermore, launching a sed process for each file name is pretty wasteful and expensive when you could just use bash's built-in substitution feature:
mv "$f" "${f/#*myfile/myfile}"
And you will find also that your working directory gets messed up. The working directory is a characteristic of the overall shell environment, so it does not automatically reset on each loop iteration. You'll need to handle that manually in some way. pushd / popd would do that, as would running the outer loop's body in a subshell.
Overall, this will do the trick:
#!/bin/bash
for d in $(find * -maxdepth 0 -type d); do
pushd "$d"
for f in *.txt; do
mv "$f" "${f/#*myfile/myfile}"
done
popd
done
You can do it without find and sed:
$ for f in */*.txt; do echo mv "$f" "${f/\/*myfile/\/myfile}"; done
mv subdir1/001myfile001A.txt subdir1/myfile001A.txt
mv subdir1/002myfile002A.txt subdir1/myfile002A.txt
mv subdir2/001myfile001B.txt subdir2/myfile001B.txt
mv subdir2/002myfile002B.txt subdir2/myfile002B.txt
If you remove the echo, it'll actually rename the files.
This uses shell parameter expansion to replace a slash and anything up to myfile with just a slash and myfile.
Notice that this breaks if there is more than one level of subdirectories. In that case, you could use extended pattern matching (enabled with shopt -s extglob) and the globstar shell option (shopt -s globstar):
$ for f in **/*.txt; do echo mv "$f" "${f/\/*([!\/])myfile/\/myfile}"; done
mv subdir1/001myfile001A.txt subdir1/myfile001A.txt
mv subdir1/002myfile002A.txt subdir1/myfile002A.txt
mv subdir1/subdir3/001myfile001A.txt subdir1/subdir3/myfile001A.txt
mv subdir1/subdir3/002myfile002A.txt subdir1/subdir3/myfile002A.txt
mv subdir2/001myfile001B.txt subdir2/myfile001B.txt
mv subdir2/002myfile002B.txt subdir2/myfile002B.txt
This uses the *([!\/]) pattern ("zero or more characters that are not a forward slash"). The slash has to be escaped in the bracket expression because we're still inside of the pattern part of the ${parameter/pattern/string} expansion.
Maybe you want to use the following command instead:
rename 's#(.*/).*(myfile.*)#$1$2#' subdir*/*
You can use rename -n ... to check the outcome without actually renaming anything.
Regarding your actual question:
The find command from the outer loop returns 3 (!) directories:
.
./subdir1
./subdir2
The unwanted . is the reason why all files end up in the parent directory (that is .). You can exclude . by using the option -mindepth 1.
Unfortunately, this was onyl the reason for the files landing in the wrong place, but not the only problem. Since you already accepted one of the answers, there is no need to list them all.
a slight modification should fix your problem:
#!/bin/bash
for f in `find . -maxdepth 2 -name "*.txt"`; do
mv "$f" "$(echo "$f" | sed -r 's,[^/]+(myfile),\1,')"
done
note: this sed uses , instead of / as the delimiter.
however, there are much faster ways.
here is with the rename utility, available or easily installed wherever there is bash and perl:
find . -maxdepth 2 -name "*.txt" | rename 's,[^/]+(myfile),/$1,'
here are tests on 1000 files:
for `find`; do mv 9.176s
rename 0.099s
that's 100x as fast.
John Bollinger's accepted answer is twice as fast as the OPs, but 50x as slow as this rename solution:
for|for|mv "$f" "${f//}" 4.316s
also, it won't work if there is a directory with too many items for a shell glob. likewise any answers that use for f in *.txt or for f in */*.txt or find * or rename ... subdir*/*. answers that begin with find ., on the other hand, will also work on directories with any number of items.
I am trying to write a bash command that will rename all the files in the current directory by omitting the last 3 characters. I am not sure if it is possible thats why I am asking here.
I have a lots of files named like this : 720-1458907789605.ts
I need to rename all of them by omitting last 3 characters to obtain from 720-1458907789605.ts ---> 720-1458907789.ts for all files in the current directory.
Is it possible using bash commands? I am new to bash scripts.
Thank you!
Native bash solution:
for f in *.ts; do
[[ -f "$f" ]] || continue # if you do not need to rename directories
mv "$f" "${f:: -6}.ts"
done
This solution is slow if you have really many files: star-expansion in for will take up memory and time.
Ref: bash substring extraction.
If you have a really large data set, a bit more complex but faster solution will be:
find . -type f -name '*.ts' -depth 1 -print0 | while read -d $\0 f; do
mv "$f" "${f%???.ts}.ts"
done
With Larry Wall's rename:
rename -n 's/...\.ts$/.ts/' *.ts
If everything looks okay remove dry run option -n.
The history of this problem is:
I have millions of files and directories on a NAS system. I found a count of 1,095,601 empty (0 byte) files. These files used to have data but were destroyed by a predecessor not using the correct toolsets to migrate data between an XSAN and this Isilon NAS.
The files were media production data, like fonts, pdfs and image files. They are no longer useful beyond the history of their existence. Before I proceed to delete them, the production user's need a record of which files used to exist, so when they browse a project folder, they can use the unaffected files but then refer to a text file in the same directory which records which files used to also be there and thus provide reason as to why certain reference files are broken.
So how do I find files across multiple directories and delete them but first output their filename to a text file which would be saved to each relevant path location?
I am thinking along the lines of:
for file in $(find . -type f -size 0); do
echo "$file" >> /PATH/TO/FOUND/FILE/PARENT/DIR/deletedFiles.txt -print0 |
xargs -0 rm ;
done
To delete each empty file while leaving behind a file called deletedFiles.txt which contains the names of the deleted files, try:
PATH=/bin:/usr/bin find . -empty -type f -execdir bash -c 'printf "%s\n" "$#" >>deletedFiles.txt' none {} + -delete
How it works
PATH=/bin:/usr/bin
This sets a temporary but secure path.
find .
This starts find looking in the current directory
-empty
This tells find to only look for empty files
-type f
This restricts find to looking for regular files.
-execdir bash -c 'printf "%s\n" "$#" >>deletedFiles.txt' none {} +
In each directory that contains an empty file, this adds the name of each empty file to the file deletedFiles.txt.
Notice the peculiar use of none in the command:
bash -c 'printf "%s\n" "$#" >>deletedFiles.txt' none {} +
When this command is run, bash will execute the string printf "%s\n" "$#" >>deletedFiles.txt and the arguments that follow that string are assigned to the positional parameters: $0, $1, $2, etc. When we use $#, it does not include $0. It, as is usual, expands to $1, $2, .... Thus, we add the placeholder none so that the placeholder is assigned is the $0, which we will ignore, and the complete list of file names are assigned to "$#".
-delete
This deletes each empty file.
Why not simply
find . -type f -size 0 -exec rm -v + |
sed -e 's%^removed .\./%%' -e 's/.$//' >deletedFiles.txt
If your find is too old to support -exec ... + you'll need to revert to -exec rm -v {} \; or refactor to
find . -type f -size 0 -print0 |
xargs -r -0 rm -v |
sed -e 's%^removed .\./%%' -e 's/.$//' >deletedFiles.txt
The brief sed script is to postprocess the output from rm -v which looks like
removed ‘./bar’
removed ‘./foo’
(with some funny quote characters around the file name) on my system. If you are fine with that output, of course, just omit the sed script from the pipeline.
If you know in advance which directories contain empty files, you can run the above snippet individually in those directories. Assuming you saved the snippet above as a script (with a proper shebang and execute permissions) named find-empty, you could simply use
for path in /path/to/first /path/to/second/directory /path/to/etc; do
cd "$path" && find-empty
done
This will only work if you have absolute paths (if not, you can run the body of the loop in a subshell by adding parentheses around it).
If you want to inspect all the directories in a tree, change the script to print to standard output instead (remove >deletedFiles.txt from the script) and try something like
find /path/to/tree -type d -exec sh -c '
t=$(mktemp -t find-emptyXXXXXXXX)
cd "$1" &&
find-empty | grep . >"$t" &&
mv "$t" deletedFiles.txt ||
rm "$t"' _ {} \;
This uses a temporary file so as to avoid updating the timestamp of directories which do not contain any empty files. The grep . is used purely for side effect; if any (non-empty) lines are printed, it will return success, whereas otherwise, it will report failure; this way, we know whether or not to move the temporary file to the target directory.
With prompting from #JonathanLeffler I have succeeded with the following:
#!/bin/bash
## call this script with: find . -type f -empty -exec handleEmpty.sh {} +
for file in "$#"
do
file2="$(basename "$file")"
echo "$file2" >> "$(dirname "$file")"/deletedFiles.txt
rm "$file"
done
This means I retain a trace of the removed files in a deletedFiles.txt flag file in each respective directory for the users to see when files are missing. That way, they can pursue going back to archive CD's to retrieve these deleted files, which are hopefully not 0 byte files.
Thanks to #John1024 for the suggestion of using the empty flag rather than size.
Part of my Bash script's intended function is to accept a directory name and then iterate through every file.
Here is part of my code:
#! /bin/bash
# sameln --- remove duplicate copies of files in specified directory
D=$1
cd $D #go to directory specified as default input
fileNum=0 #save file numbers
DIR=".*|*"
for f in $DIR #for every file in the directory
do
files[$fileNum]=$f #save that file into the array
fileNum=$((fileNum+1)) #increment the fileNum
echo aFile
done
The echo statement is for testing purposes. I passed as an argument the name of a directory with four regular files, and I expected my output to look like:
aFile
aFile
aFile
aFile
but the echo statement only shows up once.
A single operation
Use find for this, it's perfect for it.
find <dirname> -maxdepth 1 -type f -exec echo "{}" \;
The flags explained: maxdepth defines how deep int he hierarchy you want to look (dirs in dirs in dirs), type f defines files, as opposed to type d for dirs. And exec allows you to process the found file/dir, which is can be accessed through {}. You can alternatively pass it to a bash function to perform more tasks.
This simple bash script takes a dir as argument and lists all it's files:
#!/bin/bash
find "$1" -maxdepth 1 -type f -exec echo "{}" \;
Note that the last line is identical to find "$1" -maxdepth 1 -type f -print0.
Performing multiple tasks
Using find one can also perform multiple tasks by either piping to xargs or while read, but I prefer to use a function. An example:
#!/bin/bash
function dostuff {
# echo filename
echo "filename: $1"
# remove extension from file
mv "$1" "${1%.*}"
# get containing dir of file
dir="${1%/*}"
# get filename without containing dirs
file="${1##*/}"
# do more stuff like echoing results
echo "containing dir = $dir and file was called $file"
}; export -f dostuff
# export the function so you can call it in a subshell (important!!!)
find . -maxdepth 1 -type f -exec bash -c 'dostuff "{}"' \;
Note that the function needs to be exported, as you can see. This so you can call it in a subshell, which will be opened by executing bash -c 'dostuff'. To test it out, I suggest your comment to mv command in dostuff otherwise you will remove all your extensions haha.
Also note that this is safe for weird characters like spaces in filenames so no worries there.
Closing note
If you decide to go with the find command, which is a great choice, I advise you read up on it because it is a very powerful tool. A simple man find will teach you a lot and you will learn a lot of useful options to find. You can for instance quit from find once it has found a result, this can be handy to check if dirs contain videos or not for example in a rapid way. It's truly an amazing tool that can be used on various occasions and often you'll be done with a one liner (kinda like awk).
You can directly read the files into the array, then iterate through them:
#! /bin/bash
cd $1
files=(*)
for f in "${files[#]}"
do
echo $f
done
If you are iterating only files below a single directory, you are better off using simple filename/path expansion to avoid certain uncommon filename issues. The following will iterate through all files in a given directory passed as the first argument (default ./):
#!/bin/bash
srchdir="${1:-.}"
for i in "$srchdir"/*; do
printf " %s\n" "$i"
done
If you must iterate below an entire subtree that includes numerous branches, then find will likely be your only choice. However, be aware that using find or ls to populate a for loop brings with it the potential for problems with embedded characters such as a \n within a filename, etc. See Why for i in $(find . -type f) # is wrong even though unavoidable at times.
I was thinking if using a BASH script is possible without manually copying each file that is in this parent directory
"/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk
/System/Library/PrivateFrameworks"
So in this folder PrivateFrameworks, there are many subfolders and in each subfolder it consists of the file that I would like to copy it out to another location. So the structure of the path looks like this:
-PrivateFrameworks
-AccessibilityUI.framework
-AccessibilityUI <- copy this
-AccountSettings.framework
-AccountSettings <- copy this
I do not want the option of copying the entire content in the folder as there might be cases where the folders contain files which I do not want to copy. So the only way I thought of is to copy by the file extension. However as you can see, the files which I specified for copying does not have an extension(I think?). I am new to bash scripting so I am not familiar if this can be done with it.
To copy all files in or below the current directory that do not have extensions, use:
find . ! -name '*.*' -exec cp -t /your/destination/dir/ {} +
The find . command looks for all files in or below the current directory. The argument -name '*.*' would restrict that search to files that have extensions. By preceding it with a not (!), however, we get all files that do not have an extension. Then, -exec cp -t /your/destination/dir/ {} + tells find to copy those files to the destination.
To do the above starting in your directory with the long name, use:
find "/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/System/Library/PrivateFrameworks" ! -name '*.*' -exec cp -t /your/destination/dir/ {} +
UPDATE: The unix tag on this question has been removed and replaced with a OSX tag. That means we can't use the -t option on cp. The workaround is:
find . ! -name '*.*' -exec cp {} /your/destination/dir/ \;
This is less efficient because a new cp process is created for every file moved instead of once for all the files that fit on a command line. But, it will accomplish the same thing.
MORE: There are two variations of the -exec clause of a find command. In the first use above, the clause ended with {} + which tells find to fill up the end of command line with as many file names as will fit on the line.
Since OSX lacks cp -t, however, we have to put the file name in the middle of the command. So, we put {} where we want the file name and then, to signal to find where the end of the exec command is, we add a semicolon. There is a trick, though. Because bash would normally consume the semicolon itself rather than pass it on to find, we have to escape the semicolon with a backslash. That way bash gives it to the find command.
sh SCRIPT.sh copy-from-directory .extension copy-to-directory
FROM_DIR=$1
EXTENSION=$2
TO_DIR=$3
USAGE="""Usage: sh SCRIPT.sh copy-from-directory .extension copy-to-directory
- EXAMPLE: sh SCRIPT.sh PrivateFrameworks .framework .
- NOTE: 'copy-to-directory' argument is optional
"""
## print usage if less than 2 args
if [[ $# < 2 ]]; then echo "${USAGE}" && exit 1 ; fi
## set copy-to-dir default args
if [[ -z "$TO_DIR" ]] ; then TO_DIR=$PWD ; fi
## DO SOMETHING...
## find directories; find target file;
## copy target file to copy-to-dir if file exist
find $FROM_DIR -type d | while read DIR ; do
FILE_TO_COPY=$(echo $DIR | xargs basename | sed "s/$EXTENSION//")
if [[ -f $DIR/$FILE_TO_COPY ]] ; then
cp $DIR/$FILE_TO_COPY $TO_DIR
fi
done