All words only.
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cat file | tr -sc '[:alpha:]' '[\n*]' | sort | uniq -c |sort -nr |
All words and digits
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cat file | tr -sc '[:alnum:]' '[\n*]' | sort | uniq -c |sort -nr |
Sometimes piping to less on each is helpful depending on how big your file is.
This is nothing new but forgot how to do it, so just updating the blog. 🙂
Change perms for directories only.
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find . -type d -exec chmod 755 {} \; |
Change perms for files only.
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find . -type f -exec chmod 644 {} \; |
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ps -ef | grep -v grep | grep "daemonname" | awk '{print $2}' | xargs kill -9 |
fdupes -rdN dir/
r – recursive
d – preserver first file, delete other dupes
N – run silently (no prompt)
This command lists out all the files in the current directory as well as the subdirectories in the current directory.
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$ find . ./abc.txt ./subdir ./subdir/how.php ./cool.php |
The command is same as the following
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$ find . $ find . -print |
The following command will look for files in the test directory in the current directory. Lists out all files by default.
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$ find ./test ./test ./test/abc.txt ./test/subdir ./test/subdir/how.php ./test/cool.php |
The following command searches for files by their name.
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$ find ./test -name "abc.txt" ./test/abc.txt |
We can also use wildcards
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$ find ./test -name "*.php" ./test/subdir/how.php ./test/cool.php |
Note that all subdirectories are searched recursively. So this is a very powerful way to find all files of a given extension.
Trying to search the “/” directory which is the root, would search the entire file system including mounted devices and network storage devices. So be careful. Of course, you can press Ctrl + c anytime to stop the command.
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When specifying the directory ("./test" in this example), its fine to omit the trailing slash. However, if the directory is actually a symlink to some other location then you MUST specify the trailing slash for it to work properly (find ./test/ ...) |
Ignore the case
It is often useful to ignore the case when searching for file names. To ignore the case, just use the “iname” option instead of the “name” option.
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$ find ./test -iname "*.Php" ./test/subdir/how.php ./test/cool.php |
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Its always better to wrap the search term (name parameter) in double or single quotes. Not doing so will seem to work sometimes and give strange results at other times. |
The find command by default travels down the entire directory tree recursively, which is time and resource consuming. However, the depth of directory traversal can be specified. For example, we don’t want to go more than 2 or 3 levels down in the subdirectories. This is done using the maxdepth option.
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$ find ./test -maxdepth 2 -name "*.php" ./test/subdir/how.php ./test/cool.php $ find ./test -maxdepth 1 -name *.php ./test/cool.php |
The second example uses maxdepth of 1, which means it will not go lower than 1 level deep, either only in the current directory.
This is very useful when we want to do a limited search only in the current directory or max 1 level deep subdirectories and not the entire directory tree which would take more time.
Just like maxdepth there is an option called mindepth which does what the name suggests, that is, it will go at least N level deep before searching for the files.
It is also possible to search for files that do no match a given name or pattern. This is helpful when we know which files to exclude from the search.
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$ find ./test -not -name "*.php" ./test ./test/abc.txt ./test/subdir |
So in the above example, we found all files that do not have the extension of php, either non-php files. The find command also supports the exclamation mark inplace of not.
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find ./test ! -name "*.php" |
It is possible to use multiple criteria when specifying name and inverting. For example
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$ find ./test -name 'abc*' ! -name '*.php' ./test/abc.txt ./test/abc |
The above find command looks for files that begin with abc in their names and do not have a php extension. This is an example of how powerful search expressions can be built with the find command.
OR operator
When using multiple name criteria, the find command would combine them with AND operator, which means that only those files which satisfy all criteria will be matched. However, if we need to perform an OR based matching then the find command has the “o” switch.
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$ find -name '*.php' -o -name '*.txt' ./abc.txt ./subdir/how.php ./abc.php ./cool.php |
The above command search for files ending in either the php extension or the txt extension.
Sometimes we want to find only files or only directories with a given name. Find can do this easily as well.
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$ find ./test -name abc* ./test/abc.txt ./test/abc Only files $ find ./test -type f -name "abc*" ./test/abc.txt Only directories $ find ./test -type d -name "abc*" ./test/abc |
Quite useful and handy!
So let’s say you want to search inside 2 separate directories. Again, the command is very simple
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$ find ./test ./dir2 -type f -name "abc*" ./test/abc.txt ./dir2/abcdefg.txt |
Check, that it listed files from 2 separate directories.
Hidden files on Linux begin with a period. So its easy to mention that in the name criteria and list all hidden files.
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$ find ~ -type f -name ".*" |
The find command can be used to find files with a specific permission using the “perm” option. The following command searches for files with the permission 0664
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$ find . -type f -perm 0664 ./abc.txt ./subdir/how.php ./abc.php ./cool.php |
This can be useful to find files with wrong permissions which can lead to security issues. Inversion can also be applied to permission checking.
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$ find . -type f ! -perm 0777 ./abc.txt ./subdir/how.php ./abc.php ./cool.php |
The “perm” option of find command accepts the same mode string like chmod. The following command finds all files with permission 644 and sgid bit set.
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# find / -perm 2644 |
Similarly, use 1664 for sticky bit. The perm option also supports using an alternative syntax instead of octal numbers.
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$ find / -maxdepth 2 -perm /u=s 2>/dev/null /bin/mount /bin/su /bin/ping6 /bin/fusermount /bin/ping /bin/umount /sbin/mount.ecryptfs_private |
Note that the “2>/dev/null” removes those entries that have an error of “Permission Denied”
Find all Read Only files.
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$ find /etc -maxdepth 1 -perm /u=r /etc /etc/thunderbird /etc/brltty /etc/dkms /etc/phpmyadmin ... output truncated ... |
The following command will find executable files
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$ find /bin -maxdepth 2 -perm /a=x /bin /bin/preseed_command /bin/mount /bin/zfgrep /bin/tempfile ... output truncated ... |
To find all or single file called tecmint.txt under /root directory of owner root.
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$ find . -user bob . ./abc.txt ./abc ./subdir ./subdir/how.php ./abc.php |
We could also specify the name of the file or any name related criteria along with user criteria
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$ find . -user bob -name '*.php' |
It’s very easy to see, how we can build up criteria after criteria to narrow down our search for matching files.
Find all files that belong to a particular group.
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# find /var/www -group developer |
Did you know you could search your home directory by using the ~ symbol?
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$ find ~ -name "hidden.php" |
Easy!!
Another great search criteria that the find command supports is a modification and accessed date/times. This is very handy when we want to find out which files were modified as a certain time or date range. Let’s take a few examples
To find all the files which are modified 50 days back.
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# find / -mtime 50 |
Find all files that were accessed in the last 50 days.
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# find / -atime 50 |
Find all files that were modified between 50 to 100 days ago.
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# find / -mtime +50 –mtime -100 |
Find files modified within the last 1 hour.
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$ find /home/bob -cmin -60 |
To find all the files which are modified in last 1 hour.
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# find / -mmin -60 |
To find all the files which are accessed in last 1 hour.
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# find / -amin -60 |
Search files and directories based on size. To find all 50MB files, use.
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# find / -size 50M |
To find all the files which are greater than 50MB and less than 100MB.
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$ find / -size +50M -size -100M |
The find command, when used in combination with the ls and sort command, can be used to list out the largest files.
The following command will display the 5 largest file in the current directory and its subdirectory. This may take a while to execute depending on the total number of files the command has to process.
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$ find . -type f -exec ls -s {} \; | sort -n -r | head -5 |
Similarly when sorted in ascending order, it would show the smallest files first
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$ find . -type f -exec ls -s {} \; | sort -n | head -5 |
The following command uses the “empty” option of the find command, which finds all files that are empty.
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# find /tmp -type f -empty |
To file all empty directories use the type “d”.
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$ find ~/ -type d -empty |
Really very simple and easy
The find command not only finds files based on certain criteria, it can also act upon those files using any Linux command. For example, we might want to delete some files.
Here are some quick examples
Let’s say we found files using find command, and now want to list them out as the ls command would have done. This is very easy.
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$ find . -exec ls -ld {} \; drwxrwxr-x 4 enlightened enlightened 4096 Aug 11 19:01 . -rw-rw-r-- 1 enlightened enlightened 0 Aug 11 16:25 ./abc.txt drwxrwxr-x 2 enlightened enlightened 4096 Aug 11 16:48 ./abc drwxrwxr-x 2 enlightened enlightened 4096 Aug 11 16:26 ./subdir -rw-rw-r-- 1 enlightened enlightened 0 Aug 11 16:26 ./subdir/how.php -rw-rw-r-- 1 enlightened enlightened 29 Aug 11 19:13 ./abc.php -rw-rw-r-- 1 enlightened enlightened 0 Aug 11 16:25 ./cool.php |
The following command will remove all text files in the tmp directory.
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$ find /tmp -type f -name "*.txt" -exec rm -f {} \; |
The same operating can be carried out with directories, just put type d, instead of type f.
Let’s take another example where we want to delete files larger than 100MB
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$ find /home/bob/dir -type f -name *.log -size +10M -exec rm -f {} \; |
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