I have a bunch of files in a directory whose names contain numbers.
/mnt/exp-data/6/instrument/caen2018/stage0/S0Test_26060_500ns_CW_0ns_CBT_0ns_DEBT.root
/mnt/exp-data/6/instrument/caen2018/stage0/S0Run_26061_500ns_CW_0ns_CBT_0ns_DEBT.root
/mnt/exp-data/6/instrument/caen2018/stage0/S0Test_26063_500ns_CW_0ns_CBT_0ns_DEBT.root
/mnt/exp-data/6/instrument/caen2018/stage0/S0Run_26065_500ns_CW_0ns_CBT_0ns_DEBT.root
What I'd like to do is find which files are missing and then do something with those. In the above case the files which contains numbers 26062, 26064 are missing.
So far I'm doing the following
#___________________________________________________________________________________________________________________________
#-3-Find the missing runs
REPLAYED_RUNS_DIR=/ /mnt/exp-data/6/instrument/caen2018/stage0
echo "..........Looking for non replayed runs in the range $smallest_run-$biggest_run"
for (( i=$smallest_run; i<=$biggest_run; ++i));do
filename="$REPLAYED_DATA_DIR/*$i*.root"
#echo $filename
if [ ! -f $filename ]; then
echo "Run $i does not exist."
./produce_file $i
fi
done
This snippet manages to find files that are missing, however I have a few issues:
In some cases I get the following error for files that do exist and I have no idea why.
./check_missing.sh: line 53: [: /mnt/exp-data/6/instrument/caen2018/stage0/S0Run_25829_500ns_CW_0ns_CBT_0ns_DEBT.root: binary operator expected
If I uncomment echo filename the I get as an output the full name and directory of the files, as if I was doing ls instead of echo`. Is this to be expected?
Is there a better way (i,e, faster, more efficient) to do what I'm trying to do?
Here is a script to do this in a more massive way.
#!/bin/bash
d="path/to/directory"
start=$1
end=$2
join -v1 <(
seq "$start" "$end"
) <(
find "$d" -type f -printf "%f\0" |
awk -F"/" -v RS="\0" '{split($NF,a,"_"); print a[2]}' | sort
) | xargs -r -n1 echo ./produce_file
join -v1 file1 file2 will output all lines of file1 not in file2. In place of those two files, using process substitution, we put the sequence to be tested, and the filenames by find, filtered by awk to get the number in them and finally sorted, because join wants sorted inputs.
Finally you can pipe the result to your script produce_file. -r stands for --no-run-if-empty which is a GNU extension to avoid one execution with empty input if the previous command gave no arguments.
Remove echo after testing. If your script can process multiple number arguments, remove -n1 also, to process all of them at once.
Testing:
> mkdir -p path/to/directory
touch path/to/directory/S0Test_26060_0ns_CBT_0ns_DEBT.root
touch path/to/directory/S0Run_26061_500ns.root
touch path/to/directory/S0Test_26063_500ns_CW.root
touch path/to/directory/S0Test_26065_500ns.root
touch path/to/directory/S0Test_30000_500ns.root
> bash test.sh 26060 26065
./produce_file 26062
./produce_file 26064
I found another way to do it using find and [ -z "$filename"] to check if find returned an empty entry.
for (( i=$start; i<=$endn; ++i ));do
filename=`find "$DIR" -type f -name "*$i*"`
if [ -z "$filename" ]; then
echo "File $i does not exist."
fi
done
The very last line of my file should be "#"
if I tail -n 1 * | grep -L "#" the result is (standard input) obviously because it's being piped.
was hoping for a grep solution vs reading the entire file and just searching the last line.
for i in *; do tail -n 1 "$i" | grep -q -v '#' && echo "$i"; done
You can use sed for that:
sed -n 'N;${/pattern/!p}' file
The above command prints all lines of file if it's last line doesn't contain a pattern.
However, it looks like I misunderstood you, you want only to print the file names of the those files where the last line doesn't match the pattern. In this case I would use find together with the following (GNU) sed command:
find -maxdepth 1 -type f -exec sed -n '${/pattern/!F}' {} \;
The find command iterates over all files in the current folder and executes the sed command. $ marks the last line of input. If /pattern/ isn't found ! then F prints the file name.
The solution above looks nice and executes fast it has a drawback it would not print the names of empty files, since the last line will never reached and $ will not match.
For a stable solution I would suggest to put the commands into a script:
script.sh
#!/bin/bash
# Check whether the file is empty ...
if [ ! -s "$1" ] ; then
echo "$1"
else
# ... or if the last line contains a pattern
sed -n '${/pattern/!F}' "$1"
# If you don't have GNU sed you can use this
# (($(tail -n1 a.txt | grep -c pattern))) || echo "$1"
fi
make it executable
chmod +x script.sh
And use the following find command:
find -maxdepth 1 -type f -exec ./script.sh {} \;
Consider this one-liner:
while read name ; do tail -n1 "$name" | grep -q \# || echo "$name" does not contain the pattern ; done < <( find -type f )
It uses tail to get the last line of each file and grep to test that line against the pattern. Performance will not be the best on many files because two new processes are started in each iteration.
I'm making a bash script that crawls through a directory and outputs all files of a certain type into a text file. I've got that working, it just also writes out a bunch of output to console I don't want (the names of the files)
Here's the relevant code so far, tmpFile is the file I'm writing to:
for DIR in `find . -type d` # Find problem directories
do
for FILE in `ls "$DIR"` # Loop through problems in directory
do
if [[ `echo ${FILE} | grep -e prob[0-9]*_` ]]; then
`echo ${FILE} >> ${tmpFile}`
fi
done
done
The files I'm putting into the text file are in the format described by the regex prob[0-9]*_ (something like prob12345_01)
Where I pipe the output from echo ${FILE} into grep, it still outputs to stdout, something I want to avoid. I think it's a simple fix, but it's escaping me.
All this can be done in one single find command. Consider this:
find . -type f -name "prob[0-9]*_*" -exec echo {} >> ${tmpFile} \;
EDIT:
Even simpler: (Thanks to #GlennJackman)
find . -type f -name "prob[0-9]*_*" >> $tmpFile
To answer your specific question, you can pass -q to grep for silent output.
if echo "hello" | grep -q el; then
echo "found"
fi
But since you're already using find, this can be done with just one command:
find . -regex ".*prob[0-9]*_.*" -printf '%f\n' >> ${tmpFile}
find's regex is a match on the whole path, which is why the leading and trailing .* is needed.
The -printf '%f\n' prints the file name without directory, to match what your script is doing.
what you want to do is, read the output of the find command,
for every entry find returned, you want to get all (*) the files under that location
and then you want to check whether that filename matches the pattern you want
if it matches then add it to the tmpfile
while read -r dir; do
for file in "$dir"/*; do # will not match hidden files, unless dotglob is set
if [[ "$file" =~ prob[0-9]*_ ]]; then
echo "$file" >> "$tmpfile"
fi
done < <(find . -type d)
however find can do that alone
anubhava got me there ;)
so look his answer on how that's done
I have a script to identify flash files in memory to be copied or passed to a program such as vlc for playback.
#!/bin/bash
pid=($(ps aux | grep flash | grep -v grep | grep -v bin/flash))
cd "/proc/${pid[1]}/fd"
file=($(echo `ls -l | grep /tmp/`))
file="${file[8]}"
echo "$file"
This works well but I want it to return each matching file, as it is it only returns the first one.
I would normally do something like a multidimensional array but bash doesn't have those and even if it did I wouldn't know the syntax.
How do I split the output by line and then echo the [8] value from each?
You could use awk for this:
files=$(ls -l|awk -F"-> " '/\/tmp/{print $2}')
This is not failsafe at all (parsing the output of ls generally isn't).
A safer approach if your find supports it would be:
files=$(find . -type l -printf "%l\n")
(Still not safe if you have spaces in the filename.)
This should be pretty robust and give you a bash array to boot:
IFS=$'\n' files=($(find . -type l -printf "%l\n"|grep /tmp))
(still fails with filenames that contain \n.)
This handles multiple lines of output from ps, too. Maybe you can have more than one Flash process?
#!/bin/sh
for pid in $(ps aux | awk '/[f]lash/ && !/bin\/[f]lash/{print $1}); do
for file in /proc/$pid/fd/*; do
case $(readlink "$file") in
/tmp/*) echo "$file" ;;
esac
done
done
Is there a simple way, in a pretty standard UNIX environment with bash, to run a command to delete all but the most recent X files from a directory?
To give a bit more of a concrete example, imagine some cron job writing out a file (say, a log file or a tar-ed up backup) to a directory every hour. I'd like a way to have another cron job running which would remove the oldest files in that directory until there are less than, say, 5.
And just to be clear, there's only one file present, it should never be deleted.
The problems with the existing answers:
inability to handle filenames with embedded spaces or newlines.
in the case of solutions that invoke rm directly on an unquoted command substitution (rm `...`), there's an added risk of unintended globbing.
inability to distinguish between files and directories (i.e., if directories happened to be among the 5 most recently modified filesystem items, you'd effectively retain fewer than 5 files, and applying rm to directories will fail).
wnoise's answer addresses these issues, but the solution is GNU-specific (and quite complex).
Here's a pragmatic, POSIX-compliant solution that comes with only one caveat: it cannot handle filenames with embedded newlines - but I don't consider that a real-world concern for most people.
For the record, here's the explanation for why it's generally not a good idea to parse ls output: http://mywiki.wooledge.org/ParsingLs
ls -tp | grep -v '/$' | 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/%