find - Linux command line for finding files on your disk

If you need to find files in your disk, you have two command lines options (at least I know two)

1. Find
2. Locate

We now will look at Find

Description
Files files based on a search criteria.

usage
find [directory-list] [expression]

Directory List

specifies find which directories to look for files you can specify more than one direcotory i.e.:
find /home/jhon /etc -name file.txt
This way it will look at /home/jhon/ and also at /etc/ and all its subdirectories, find always look at the subdirectories, if you do not specify any directory list it will look in the working directory

Expression

The expression is made up of options, tests and actions. If the expression contains no actions -print is executed and all files (on the specified directory list) will be listed.
You can separate two options in the expression and will a boolean and if you want an or use -o separating them.
Use a ! if you want to negate the result of any of the options.

Options/test/actions

-anewer file
File was last accessed more recently than file was modified. If
file is a symbolic link and the -H option or the -L option is in
effect, the access time of the file it points to is always used.

-atime n
File was last accessed n*24 hours ago. When find figures out
how many 24-hour periods ago the file was last accessed, any
fractional part is ignored, so to match -atime +1, a file has to
have been accessed at least two days ago.

-cnewer file
File’s status was last changed more recently than file was modi?
fied. If file is a symbolic link and the -H option or the -L
option is in effect, the status-change time of the file it
points to is always used.

-ctime n
File’s status was last changed n*24 hours ago. See the comments
for -atime to understand how rounding affects the interpretation
of file status change times.

-follow
When specified and find encounters a symbolic link, it will follows the link

-group gname
File belongs to group gname (numeric group ID allowed).

-ilname pattern
Like -lname, but the match is case insensitive. If the -L
option or the -follow option is in effect, this test returns
false unless the symbolic link is broken.

-iname pattern
Like -name, but the match is case insensitive. For example, the
patterns ‘fo*’ and ‘F??’ match the file names ‘Foo’, ‘FOO’,
‘foo’, ‘fOo’, etc. In these patterns, unlike filename expan?
sion by the shell, an initial ’.’ can be matched by ’*’. That
is, find -name *bar will match the file ‘.foobar’. Please note
that you should quote patterns as a matter of course, otherwise
the shell will expand any wildcard characters in them.

-inum n
File has inode number n. It is normally easier to use the
-samefile test instead.

-links n
File has n links.

-name pattern
Base of file name (the path with the leading directories
removed) matches shell pattern pattern. The metacharacters
(‘*’, ‘?’, and ‘[]’) match a ‘.’ at the start of the base name
(this is a change in findutils-4.2.2; see section STANDARDS CON?
FORMANCE below). To ignore a directory and the files under it,
use -prune; see an example in the description of -wholename.
Braces are not recognised as being special, despite the fact
that some shells including Bash imbue braces with a special
meaning in shell patterns. The filename matching is performed
with the use of the fnmatch(3) library function. Don’t forget
to enclose the pattern in quotes in order to protect it from
expansion by the shell.

-user name
The file meets this criterion if it belongs to the user with that username.

You can check man find for all other options.

Example:
find /home/user/ -name file.txt

Will look for all files with extension txt in the directory /home/user/, this is maybe the most used way.