I have a delete backup files function which takes in the arguments as a directory name and to backup the files of a specific directory and specific type of file like this delete_old_backup_files $(dirname $$abc) "$abc.*"
The function body is:
local fpath=$1
local fexpr=$2
# delete backup files older than a day
find $fpath -name "${fexpr##*/}" -mmin +1 -type f | xargs rm -f
Currently deleting files that are older than a day. Now I want to modify the function such that this function should delete all backup files of type $abc.*, except the last 5 backup files created. Tried various commands using stat or -printf but couldn't succeed.
What is the correct way of completing this function?
Assuming the filenames do not contain newline characters, would you please
try:
delete_old_backup_files() {
local fpath=$1
local fexpr=$2
find "$fpath" -type f -name "${fexpr##*/}" -printf "%T#\t%p\n" | sort -nr | tail -n +6 | cut -f2- | xargs rm -f --
}
-printf "%T#\t%p\n" prints the seconds since epoch (%T#) followed
by a tab character (\t) then the filename (%p) and a newline (\n).
sort -nr numerically sorts the lines in descending order (newer first,
older last).
tail -n +6 prints the 6th and following lines.
cut -f2- removes the prepended timestamp leaving the filename only.
[Edit]
In case of MacOS, please try instead (not tested):
find "$fpath" -type f -print0 | xargs -0 stat -f "%m%t%N" | sort -nr | tail -n +6 | cut -f2- | xargs rm --
In the stat command, %m is expanded to the modification time (seconds since epoch), %t is replaced with a tab, and %N to be a filename.
I would use sorting instead of find. You can use ls -t
$ touch a b c
$ sleep 3
$ touch d e f
ls -t | tr ' ' '\n' | tail -n +4
a
b
c
$ ls -t | tr ' ' '\n' | tail -n +4 | xargs rm
$ ls
d e f
From man ls:
-t sort by modification time, newest first
Make sure you create backups before you delete stuff :-)
I am trying to monitor the progress of the newest five files and I want to see the last few lines of the each of them.
I was able to get the newest five files using the command:
ls *.log -lt | head -5
but I want to iterate through these five files and display the last 10 lines of each file. I was wondering if it can be done in a single bash command instead of a loop. But if it can't be done, I would appreciate a bash loop implementation too
tail can take multiple file names.
tail -n 10 $(ls -t *.log | head -5)
Add -F to monitor them continuously for changes.
If the file names might have spaces xargs will be more robust:
ls -t *.log | head -5 | xargs -d '\n' tail -n 10
Assuming the file names and path names do not contain special characters such as TAB or newline, how about:
while true; do
find . -type f -name "*.log" -printf "%T#\t%p\n" | sort -n | tail -5 | cut -f2 | xargs tail -10
sleep 1
done
ls *.log -1t | head -5 | while IFS= read -r file; do tail -10 "$file"; done
I have a number of files (these are randomly generated each time) that have a number in the name – within the file, the number is repeated. Example:
file1_85.txt
file1_242.txt
file1_9.txt
I want to cat the contents of these files into one larger file, file_all.txt.
The code that I tried using is this:
for f in file1_*.txt; do (cat "${f}"; echo " ") >> file_all.txt; done
However, the contents of file_all.txt look like this:
file1_242.txt
file1_85.txt
file1_9.txt
When I really want it to look like this:
file1_9.txt
file1_85.txt
file1_242.txt
Which would happen if bash cat the files in numerical order.
I have tried this:
for f in file1_{1..99999}.txt; do (cat "${f}"; echo " ") >> file_all.txt; done
Which worked, however I got error messages "No such file or directory" when it passed through a number that did not have a matching file. Also, this is very time consuming. Is there a better way to carry out this task?
Assuming the files don't have any newlines in their names, and you have the GNU version of sort, this will work:
while read file; do
cat "$file"
echo
done < <(ls -1 file_*.txt | sort -V) > file_all.txt
If your sort doesn't support -V (as on e.g. OS X), you can take advantage of the filename consistency to do a straight numeric sort instead:
while read file; do
cat "$file"
echo
done < <(ls -1 file_*.txt | sort -t_ -n -k2,2) > file_all.txt
Finally, if your files contain newlines, you can still use sort, but you need to use the -z option in conjunction with other tools that terminate elements of a list with NUL bytes instead of newlines:
find . -depth 1 -name 'file_*' -print0 | sort -zV | xargs -0 -I{} bash -c 'cat {}; echo'
Replace the sort -zV with sort -z -t_ -n -k2,2 for an older version of GNU sort that lacks the -V option; a totally non-GNU sort probably won't have -z either, though.
For filenames potentially containing newlines:
$ find -name 'file1*' -print0 | sort -zV | xargs -0 cat
file1_9
file1_85
file1_242
or, if the -V option is not available,
$ find -name 'file1*' -print0 | sort -z -n -t '_' -k 2 | xargs -0 cat
file1_9
file1_85
file1_242
This uses null separated filenames; the -z option tells sort to expect (and produce) null separated filenames, and xargs -0 is for null separated input as well.
Your "brute force" approach would work if:
$ for f in file1_{1..99999}.txt; do [ -f "${f}" ] && cat "${f}" >> file_all.txt; done
The comparison: [ -f "${f}" ] check if the file exists before cat, avoiding the error message.
I need to count the number of files on a large number of directories. Is there an easy way to do this with a shell script (using find, wc, sed, awk or similar)? Just to avoid having to write a proper script in python.
The output would be something like this:
$ <magic_command>
dir1 2
dir2 12
dir3 5
The number after the dir name would be the number of files. A plus would be able to turn counting of dot/hidden files on and off.
Thanks!
Try the below one:
du -a | cut -d/ -f2 | sort | uniq -c | sort -nr
from http://www.linuxquestions.org/questions/linux-newbie-8/how-to-find-the-total-number-of-files-in-a-folder-510009/#post3466477
find <dir> -type f | wc -l
find -type f will list all files in the specified directory one at each line, wc -l count the amount of newlines seen from stdin.
Also for future reference: answers like this are a google away.
More or less what I was looking for:
find . -type d -exec sh -c 'echo "{}" `ls "{}" |wc -l`' \;
try ls | wc it list the file in your directory and gives list of file output to wc as input
One way like this:
$ for dir in $(find . -type d )
> do
> echo $dir $(ls -A $dir | wc -l )
> done
Just remove the -A option if you do not want the hidden file count
find . -type d | xargs ls -1 | perl -lne 'if(/^\./ || eof){print $a." ".$count;$a=$_;$count=-1}else{$count++}'
below is the test:
> find . -type d
.
./SunWS_cache
./wicked
./wicked/segvhandler
./test
./test/test2
./test/tempdir.
./signal_handlers
./signal_handlers/part2
> find . -type d | xargs ls -1 | perl -lne 'if(/^\./ || eof){print $a." ".$count;$a=$_;$count=-1}else{$count++}'
.: 79
./SunWS_cache: 4
./signal_handlers: 6
./signal_handlers/part2: 5
./test: 6
./test/tempdir.: 0
./test/test2: 0
./wicked: 4
./wicked/segvhandler: 9
A generic version of Mehdi Karamosly's solution to list folders of any directory without changing current directory
DIR=~/test/ sh -c 'cd $DIR; du -a | cut -d/ -f2 | sort | uniq -c | sort -nr'
Explanation:
Extract directory into variable
Start new shell
Change directory in that shell so that current shell's directory stays same
Process
I use these functions:
nf()(for d;do echo $(ls -A -- "$d"|wc -l) "$d";done)
nfr()(for d;do echo $(find "$d" -mindepth 1|wc -l) "$d";done)
Both assume that filenames don't contain newlines.
Here's bash-only versions:
nf()(shopt -s nullglob dotglob;for d;do a=("$d"/*);echo "${#a[#]} $d";done)
nfr()(shopt -s nullglob dotglob globstar;for d;do a=("$d"/**);echo "${#a[#]} $d";done)
I liked the output from the du based answer, but when I was looking at a large filesystem it was taking ages, so I put together a small ls based script which gives the same output, but much quicker:
for dir in `ls -1A ~/test/`;
do
echo "$dir `ls -R1Ap ~/test/$dir | grep -Ev "[/:]|^\s*$" | wc -l`"
done
You can try out copying the output of ls command in a text file and then count the number of lines in that file.
ls $LOCATION > outText.txt; NUM_FILES=$(wc -w outText.txt); echo $NUM_FILES
find -type f -printf '%h\n' | sort | uniq -c | sort -n
Is there a simple way, in a pretty standard UNIX environment with bash, to run a command to delete all but the most recent X files from a directory?
To give a bit more of a concrete example, imagine some cron job writing out a file (say, a log file or a tar-ed up backup) to a directory every hour. I'd like a way to have another cron job running which would remove the oldest files in that directory until there are less than, say, 5.
And just to be clear, there's only one file present, it should never be deleted.
The problems with the existing answers:
inability to handle filenames with embedded spaces or newlines.
in the case of solutions that invoke rm directly on an unquoted command substitution (rm `...`), there's an added risk of unintended globbing.
inability to distinguish between files and directories (i.e., if directories happened to be among the 5 most recently modified filesystem items, you'd effectively retain fewer than 5 files, and applying rm to directories will fail).
wnoise's answer addresses these issues, but the solution is GNU-specific (and quite complex).
Here's a pragmatic, POSIX-compliant solution that comes with only one caveat: it cannot handle filenames with embedded newlines - but I don't consider that a real-world concern for most people.
For the record, here's the explanation for why it's generally not a good idea to parse ls output: http://mywiki.wooledge.org/ParsingLs
ls -tp | grep -v '/$' | tail -n +6 | xargs -I {} rm -- {}
Note: This command operates in the current directory; to target a directory explicitly, use a subshell ((...)) with cd:
(cd /path/to && ls -tp | grep -v '/$' | tail -n +6 | xargs -I {} rm -- {})
The same applies analogously to the commands below.
The above is inefficient, because xargs has to invoke rm separately for each filename.
However, your platform's specific xargs implementation may allow you to solve this problem:
A solution that works with GNU xargs is to use -d '\n', which makes xargs consider each input line a separate argument, yet passes as many arguments as will fit on a command line at once:
ls -tp | grep -v '/$' | tail -n +6 | xargs -d '\n' -r rm --
Note: Option -r (--no-run-if-empty) ensures that rm is not invoked if there's no input.
A solution that works with both GNU xargs and BSD xargs (including on macOS) - though technically still not POSIX-compliant - is to use -0 to handle NUL-separated input, after first translating newlines to NUL (0x0) chars., which also passes (typically) all filenames at once:
ls -tp | grep -v '/$' | tail -n +6 | tr '\n' '\0' | xargs -0 rm --
Explanation:
ls -tp prints the names of filesystem items sorted by how recently they were modified , in descending order (most recently modified items first) (-t), with directories printed with a trailing / to mark them as such (-p).
Note: It is the fact that ls -tp always outputs file / directory names only, not full paths, that necessitates the subshell approach mentioned above for targeting a directory other than the current one ((cd /path/to && ls -tp ...)).
grep -v '/$' then weeds out directories from the resulting listing, by omitting (-v) lines that have a trailing / (/$).
Caveat: Since a symlink that points to a directory is technically not itself a directory, such symlinks will not be excluded.
tail -n +6 skips the first 5 entries in the listing, in effect returning all but the 5 most recently modified files, if any.
Note that in order to exclude N files, N+1 must be passed to tail -n +.
xargs -I {} rm -- {} (and its variations) then invokes on rm on all these files; if there are no matches at all, xargs won't do anything.
xargs -I {} rm -- {} defines placeholder {} that represents each input line as a whole, so rm is then invoked once for each input line, but with filenames with embedded spaces handled correctly.
-- in all cases ensures that any filenames that happen to start with - aren't mistaken for options by rm.
A variation on the original problem, in case the matching files need to be processed individually or collected in a shell array:
# One by one, in a shell loop (POSIX-compliant):
ls -tp | grep -v '/$' | tail -n +6 | while IFS= read -r f; do echo "$f"; done
# One by one, but using a Bash process substitution (<(...),
# so that the variables inside the `while` loop remain in scope:
while IFS= read -r f; do echo "$f"; done < <(ls -tp | grep -v '/$' | tail -n +6)
# Collecting the matches in a Bash *array*:
IFS=$'\n' read -d '' -ra files < <(ls -tp | grep -v '/$' | tail -n +6)
printf '%s\n' "${files[#]}" # print array elements
Remove all but 5 (or whatever number) of the most recent files in a directory.
rm `ls -t | awk 'NR>5'`
(ls -t|head -n 5;ls)|sort|uniq -u|xargs rm
This version supports names with spaces:
(ls -t|head -n 5;ls)|sort|uniq -u|sed -e 's,.*,"&",g'|xargs rm
Simpler variant of thelsdj's answer:
ls -tr | head -n -5 | xargs --no-run-if-empty rm
ls -tr displays all the files, oldest first (-t newest first, -r reverse).
head -n -5 displays all but the 5 last lines (ie the 5 newest files).
xargs rm calls rm for each selected file.
find . -maxdepth 1 -type f -printf '%T# %p\0' | sort -r -z -n | awk 'BEGIN { RS="\0"; ORS="\0"; FS="" } NR > 5 { sub("^[0-9]*(.[0-9]*)? ", ""); print }' | xargs -0 rm -f
Requires GNU find for -printf, and GNU sort for -z, and GNU awk for "\0", and GNU xargs for -0, but handles files with embedded newlines or spaces.
All these answers fail when there are directories in the current directory. Here's something that works:
find . -maxdepth 1 -type f | xargs -x ls -t | awk 'NR>5' | xargs -L1 rm
This:
works when there are directories in the current directory
tries to remove each file even if the previous one couldn't be removed (due to permissions, etc.)
fails safe when the number of files in the current directory is excessive and xargs would normally screw you over (the -x)
doesn't cater for spaces in filenames (perhaps you're using the wrong OS?)
ls -tQ | tail -n+4 | xargs rm
List filenames by modification time, quoting each filename. Exclude first 3 (3 most recent). Remove remaining.
EDIT after helpful comment from mklement0 (thanks!): corrected -n+3 argument, and note this will not work as expected if filenames contain newlines and/or the directory contains subdirectories.
Ignoring newlines is ignoring security and good coding. wnoise had the only good answer. Here is a variation on his that puts the filenames in an array $x
while IFS= read -rd ''; do
x+=("${REPLY#* }");
done < <(find . -maxdepth 1 -printf '%T# %p\0' | sort -r -z -n )
For Linux (GNU tools), an efficient & robust way to keep the n newest files in the current directory while removing the rest:
n=5
find . -maxdepth 1 -type f -printf '%T# %p\0' |
sort -z -nrt ' ' -k1,1 |
sed -z -e "1,${n}d" -e 's/[^ ]* //' |
xargs -0r rm -f
For BSD, find doesn't have the -printf predicate, stat can't output NULL bytes, and sed + awk can't handle NULL-delimited records.
Here's a solution that doesn't support newlines in paths but that safeguards against them by filtering them out:
#!/bin/bash
n=5
find . -maxdepth 1 -type f ! -path $'*\n*' -exec stat -f '%.9Fm %N' {} + |
sort -nrt ' ' -k1,1 |
awk -v n="$n" -F'^[^ ]* ' 'NR > n {printf "%s%c", $2, 0}' |
xargs -0 rm -f
note: I'm using bash because of the $'\n' notation. For sh you can define a variable containing a literal newline and use it instead.
Solution for UNIX & Linux (inspired from AIX/HP-UX/SunOS/BSD/Linux ls -b):
Some platforms don't provide find -printf, nor stat, nor support NUL-delimited records with stat/sort/awk/sed/xargs. That's why using perl is probably the most portable way to tackle the problem, because it is available by default in almost every OS.
I could have written the whole thing in perl but I didn't. I only use it for substituting stat and for encoding-decoding-escaping the filenames. The core logic is the same as the previous solutions and is implemented with POSIX tools.
note: perl's default stat has a resolution of a second, but starting from perl-5.8.9 you can get sub-second resolution with the stat function of the module Time::HiRes (when both the OS and the filesystem support it). That's what I'm using here; if your perl doesn't provide it then you can remove the ‑MTime::HiRes=stat from the command line.
n=5
find . '(' -name '.' -o -prune ')' -type f -exec \
perl -MTime::HiRes=stat -le '
foreach (#ARGV) {
#st = stat($_);
if ( #st > 0 ) {
s/([\\\n])/sprintf( "\\%03o", ord($1) )/ge;
print sprintf( "%.9f %s", $st[9], $_ );
}
else { print STDERR "stat: $_: $!"; }
}
' {} + |
sort -nrt ' ' -k1,1 |
sed -e "1,${n}d" -e 's/[^ ]* //' |
perl -l -ne '
s/\\([0-7]{3})/chr(oct($1))/ge;
s/(["\n])/"\\$1"/g;
print "\"$_\"";
' |
xargs -E '' sh -c '[ "$#" -gt 0 ] && rm -f "$#"' sh
Explanations:
For each file found, the first perl gets the modification time and outputs it along the encoded filename (each newline and backslash characters are replaced with the literals \012 and \134 respectively).
Now each time filename is guaranteed to be single-line, so POSIX sort and sed can safely work with this stream.
The second perl decodes the filenames and escapes them for POSIX xargs.
Lastly, xargs calls rm for deleting the files. The sh command is a trick that prevents xargs from running rm when there's no files to delete.
I realize this is an old thread, but maybe someone will benefit from this. This command will find files in the current directory :
for F in $(find . -maxdepth 1 -type f -name "*_srv_logs_*.tar.gz" -printf '%T# %p\n' | sort -r -z -n | tail -n+5 | awk '{ print $2; }'); do rm $F; done
This is a little more robust than some of the previous answers as it allows to limit your search domain to files matching expressions. First, find files matching whatever conditions you want. Print those files with the timestamps next to them.
find . -maxdepth 1 -type f -name "*_srv_logs_*.tar.gz" -printf '%T# %p\n'
Next, sort them by the timestamps:
sort -r -z -n
Then, knock off the 4 most recent files from the list:
tail -n+5
Grab the 2nd column (the filename, not the timestamp):
awk '{ print $2; }'
And then wrap that whole thing up into a for statement:
for F in $(); do rm $F; done
This may be a more verbose command, but I had much better luck being able to target conditional files and execute more complex commands against them.
If the filenames don't have spaces, this will work:
ls -C1 -t| awk 'NR>5'|xargs rm
If the filenames do have spaces, something like
ls -C1 -t | awk 'NR>5' | sed -e "s/^/rm '/" -e "s/$/'/" | sh
Basic logic:
get a listing of the files in time order, one column
get all but the first 5 (n=5 for this example)
first version: send those to rm
second version: gen a script that will remove them properly
With zsh
Assuming you don't care about present directories and you will not have more than 999 files (choose a bigger number if you want, or create a while loop).
[ 6 -le `ls *(.)|wc -l` ] && rm *(.om[6,999])
In *(.om[6,999]), the . means files, the o means sort order up, the m means by date of modification (put a for access time or c for inode change), the [6,999] chooses a range of file, so doesn't rm the 5 first.
Adaptation of #mklement0's excellent answer with some parameters and without needing to navigate to the folder containing the files to be deleted...
TARGET_FOLDER="/my/folder/path"
FILES_KEEP=5
ls -tp "$TARGET_FOLDER"**/* | grep -v '/$' | tail -n +$((FILES_KEEP+1)) | xargs -d '\n' -r rm --
[Ref(s).: https://stackoverflow.com/a/3572628/3223785 ]
Thanks! 😉
found interesting cmd in Sed-Onliners - Delete last 3 lines - fnd it perfect for another way to skin the cat (okay not) but idea:
#!/bin/bash
# sed cmd chng #2 to value file wish to retain
cd /opt/depot
ls -1 MyMintFiles*.zip > BigList
sed -n -e :a -e '1,2!{P;N;D;};N;ba' BigList > DeList
for i in `cat DeList`
do
echo "Deleted $i"
rm -f $i
#echo "File(s) gonzo "
#read junk
done
exit 0
Removes all but the 10 latest (most recents) files
ls -t1 | head -n $(echo $(ls -1 | wc -l) - 10 | bc) | xargs rm
If less than 10 files no file is removed and you will have :
error head: illegal line count -- 0
To count files with bash
I needed an elegant solution for the busybox (router), all xargs or array solutions were useless to me - no such command available there. find and mtime is not the proper answer as we are talking about 10 items and not necessarily 10 days. Espo's answer was the shortest and cleanest and likely the most unversal one.
Error with spaces and when no files are to be deleted are both simply solved the standard way:
rm "$(ls -td *.tar | awk 'NR>7')" 2>&-
Bit more educational version: We can do it all if we use awk differently. Normally, I use this method to pass (return) variables from the awk to the sh. As we read all the time that can not be done, I beg to differ: here is the method.
Example for .tar files with no problem regarding the spaces in the filename. To test, replace "rm" with the "ls".
eval $(ls -td *.tar | awk 'NR>7 { print "rm \"" $0 "\""}')
Explanation:
ls -td *.tar lists all .tar files sorted by the time. To apply to all the files in the current folder, remove the "d *.tar" part
awk 'NR>7... skips the first 7 lines
print "rm \"" $0 "\"" constructs a line: rm "file name"
eval executes it
Since we are using rm, I would not use the above command in a script! Wiser usage is:
(cd /FolderToDeleteWithin && eval $(ls -td *.tar | awk 'NR>7 { print "rm \"" $0 "\""}'))
In the case of using ls -t command will not do any harm on such silly examples as: touch 'foo " bar' and touch 'hello * world'. Not that we ever create files with such names in real life!
Sidenote. If we wanted to pass a variable to the sh this way, we would simply modify the print (simple form, no spaces tolerated):
print "VarName="$1
to set the variable VarName to the value of $1. Multiple variables can be created in one go. This VarName becomes a normal sh variable and can be normally used in a script or shell afterwards. So, to create variables with awk and give them back to the shell:
eval $(ls -td *.tar | awk 'NR>7 { print "VarName=\""$1"\"" }'); echo "$VarName"
leaveCount=5
fileCount=$(ls -1 *.log | wc -l)
tailCount=$((fileCount - leaveCount))
# avoid negative tail argument
[[ $tailCount < 0 ]] && tailCount=0
ls -t *.log | tail -$tailCount | xargs rm -f
I made this into a bash shell script. Usage: keep NUM DIR where NUM is the number of files to keep and DIR is the directory to scrub.
#!/bin/bash
# Keep last N files by date.
# Usage: keep NUMBER DIRECTORY
echo ""
if [ $# -lt 2 ]; then
echo "Usage: $0 NUMFILES DIR"
echo "Keep last N newest files."
exit 1
fi
if [ ! -e $2 ]; then
echo "ERROR: directory '$1' does not exist"
exit 1
fi
if [ ! -d $2 ]; then
echo "ERROR: '$1' is not a directory"
exit 1
fi
pushd $2 > /dev/null
ls -tp | grep -v '/' | tail -n +"$1" | xargs -I {} rm -- {}
popd > /dev/null
echo "Done. Kept $1 most recent files in $2."
ls $2|wc -l
Modified version of the answer of #Fabien if you want to specify a path. Useful if you're running the script elsewhere.
ls -tr /path/foo/ | head -n -5 | xargs -I% --no-run-if-empty rm /path/foo/%