Doing command-line stuff in Linux is fun. It may be intimidating for some at first, now that we are in the age where GUI is no longer an option. But with CLI, we can do so many things that can be accomplished faster if we know how to utilize the features of a certain command.
One command that is very flexible is find. With find, you can search not only based on filenames, you can also use other identifiers like GUI and UID, timestamps and file types.
Here are some examples of find commands:
This command will find all files in /home directory with .doc as extension and was modified 24 hours ago:
find /home -name *.doc -mtime 1
This one will find the same files, but not directories, and delete them using -exec option (great for disk usage maintenance, but BACKUP first!):
find /home -name *.doc -type f -mtime 1 -exec rm ’{}’ \;
You can also find files owned by a certain UID:
find /tmp -user johndoe find /tmp -uid 502
Or by GID:
find /home/development -gid 1000
You can also search for files and directories with certain permissions:
find . -perm -777
And from those examples, you can build your own command to find what you are looking for.
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It’d be a good idea to single quote your wildcard so that your shell does not expand it before the search.
e.g.:
find /home -name '*.doc' -mtime 1as regards deleting files, i’d suggest to pipe find’s results to xargs for efficiency reasons, e.g.:
find … -print0 | xargs -0 rm
this results in a single call to rm, instead of one call per file found.
Quoting {} is unnecessary:
$ touch "a b"
$ find . -name a\*b
./a b
$ find . -name a\*b -exec ls {} \;
./a b
$ find . -name a\*b -exec rm {} \;
$ find . -name a\*b
$
For finding files older than a certain time, you might want to use relative time, e.g.,
$ find /home -mtime +1
The commands provided only find files modified 24 hours ago; this example finds files modified 24 hours or more ago. Likewise,
$ find /home -mtime 1
finds files modified about 24 hours ago, while
$ find /home -mtime 0
and
$ find /home -mtime -1
both find files modified less than 24 hours ago, but don’t find quite the same files, due to slight rounding differences when find calculates the time period.
One of the first changes I used to make any Unix system I inherited was to replace the “rm -rf /tmp/*” command found in startup scripts with
find /tmp -mtime +7 -exec /bin/rm -rf {} \;
which deletes all files/directories unmmodified in more than 7 days. Why? Because sometimes /tmp contains core and log files useful to figuring out why your system crashed - and having “rm -rf /tmp/*” in startup scripts cleaned them out.
find . -empty -delete
I like this one and other thing I like is that mostly all -exec rm -rf {} \; can be replaced with -delete
i prefer “-iname” over “-name” to make it case insensitive.
I kept having problems with the stupid error msg saying find: paths must precede expressions.