dtos-dotfiles/org-yeah/find.org

#+TITLE: find
#+DESCRIPTION: Org-Man pages - find
#+SETUPFILE: ./org-html-themes/org/theme-readtheorg.setup
#+OPTIONS: num:nil ^:{}
#+INCLUDE: "./header.org"

* NAME
find - search for files in a directory hierarchy

* SYNOPSIS
*find* [-H] [-L] [-P] [-D debugopts] [-Olevel] [starting-point...]
[expression]

* TLDR
The examples in the table below are from tldr-pages project: https://tldr.sh
#+begin_example
- Find files by extension:
  find root_path -name '*.ext'

- Find files matching multiple path/name patterns:
  find root_path -path '**/path/**/*.ext' -or -name '*pattern*'

- Find directories matching a given name, in case-insensitive mode:
  find root_path -type d -iname '*lib*'

- Find files matching a given pattern, excluding specific paths:
  find root_path -name '*.py' -not -path '*/site-packages/*'

- Find files matching a given size range:
  find root_path -size +500k -size -10M

- Run a command for each file (use `{}` within the command to access the filename):
  find root_path -name '*.ext' -exec wc -l {} \;

- Find files modified in the last 7 days and delete them:
  find root_path -daystart -mtime -7 -delete

- Find empty (0 byte) files and delete them:
  find root_path -type f -empty -delete
#+end_example

* DESCRIPTION
This manual page documents the GNU version of *find*. GNU *find*
searches the directory tree rooted at each given starting-point by
evaluating the given expression from left to right, according to the
rules of precedence (see section OPERATORS), until the outcome is known
(the left hand side is false for /and/ operations, true for /or/), at
which point *find* moves on to the next file name. If no starting-point
is specified, `.' is assumed.

If you are using *find* in an environment where security is important
(for example if you are using it to search directories that are writable
by other users), you should read the `Security Considerations' chapter
of the findutils documentation, which is called *Finding Files* and
comes with findutils. That document also includes a lot more detail and
discussion than this manual page, so you may find it a more useful
source of information.

* OPTIONS
The *-H*, *-L* and *-P* options control the treatment of symbolic links.
Command-line arguments following these are taken to be names of files or
directories to be examined, up to the first argument that begins with
`-', or the argument `(' or `!'. That argument and any following
arguments are taken to be the expression describing what is to be
searched for. If no paths are given, the current directory is used. If
no expression is given, the expression *-print* is used (but you should
probably consider using *-print0* instead, anyway).

This manual page talks about `options' within the expression list. These
options control the behaviour of *find* but are specified immediately
after the last path name. The five `real' options *-H*, *-L*, *-P*, *-D*
and *-O* must appear before the first path name, if at all. A double
dash *--* could theoretically be used to signal that any remaining
arguments are not options, but this does not really work due to the way
*find* determines the end of the following path arguments: it does that
by reading until an expression argument comes (which also starts with a
`-'). Now, if a path argument would start with a `-', then *find* would
treat it as expression argument instead. Thus, to ensure that all start
points are taken as such, and especially to prevent that wildcard
patterns expanded by the calling shell are not mistakenly treated as
expression arguments, it is generally safer to prefix wildcards or
dubious path names with either `./' or to use absolute path names
starting with '/'.

- -P :: Never follow symbolic links. This is the default behaviour. When
  *find* examines or prints information about files, and the file is a
  symbolic link, the information used shall be taken from the properties
  of the symbolic link itself.

- -L :: Follow symbolic links. When *find* examines or prints
  information about files, the information used shall be taken from the
  properties of the file to which the link points, not from the link
  itself (unless it is a broken symbolic link or *find* is unable to
  examine the file to which the link points). Use of this option implies
  *-noleaf*. If you later use the *-P* option, *-noleaf* will still be
  in effect. If *-L* is in effect and *find* discovers a symbolic link
  to a subdirectory during its search, the subdirectory pointed to by
  the symbolic link will be searched.

  When the *-L* option is in effect, the *-type* predicate will always
  match against the type of the file that a symbolic link points to
  rather than the link itself (unless the symbolic link is broken).
  Actions that can cause symbolic links to become broken while *find* is
  executing (for example *-delete*) can give rise to confusing
  behaviour. Using *-L* causes the *-lname* and *-ilname* predicates
  always to return false.

- -H :: Do not follow symbolic links, except while processing the
  command line arguments. When *find* examines or prints information
  about files, the information used shall be taken from the properties
  of the symbolic link itself. The only exception to this behaviour is
  when a file specified on the command line is a symbolic link, and the
  link can be resolved. For that situation, the information used is
  taken from whatever the link points to (that is, the link is
  followed). The information about the link itself is used as a fallback
  if the file pointed to by the symbolic link cannot be examined. If
  *-H* is in effect and one of the paths specified on the command line
  is a symbolic link to a directory, the contents of that directory will
  be examined (though of course *-maxdepth 0* would prevent this).

If more than one of *-H*, *-L* and *-P* is specified, each overrides the
others; the last one appearing on the command line takes effect. Since
it is the default, the *-P* option should be considered to be in effect
unless either *-H* or *-L* is specified.

GNU *find* frequently stats files during the processing of the command
line itself, before any searching has begun. These options also affect
how those arguments are processed. Specifically, there are a number of
tests that compare files listed on the command line against a file we
are currently considering. In each case, the file specified on the
command line will have been examined and some of its properties will
have been saved. If the named file is in fact a symbolic link, and the
*-P* option is in effect (or if neither *-H* nor *-L* were specified),
the information used for the comparison will be taken from the
properties of the symbolic link. Otherwise, it will be taken from the
properties of the file the link points to. If *find* cannot follow the
link (for example because it has insufficient privileges or the link
points to a nonexistent file) the properties of the link itself will be
used.

When the *-H* or *-L* options are in effect, any symbolic links listed
as the argument of *-newer* will be dereferenced, and the timestamp will
be taken from the file to which the symbolic link points. The same
consideration applies to *-newerXY*, *-anewer* and *-cnewer*.

The *-follow* option has a similar effect to *-L*, though it takes
effect at the point where it appears (that is, if *-L* is not used but
*-follow* is, any symbolic links appearing after *-follow* on the
command line will be dereferenced, and those before it will not).

- -D debugopts :: Print diagnostic information; this can be helpful to
  diagnose problems with why *find* is not doing what you want. The list
  of debug options should be comma separated. Compatibility of the debug
  options is not guaranteed between releases of findutils. For a
  complete list of valid debug options, see the output of *find -D
  help*. Valid debug options include

  - exec :: Show diagnostic information relating to -exec, -execdir, -ok
    and -okdir

  - opt :: Prints diagnostic information relating to the optimisation of
    the expression tree; see the -O option.

  - rates :: Prints a summary indicating how often each predicate
    succeeded or failed.

  - search :: Navigate the directory tree verbosely.

  - stat :: Print messages as files are examined with the *stat* and
    *lstat* system calls. The *find* program tries to minimise such
    calls.

  - tree :: Show the expression tree in its original and optimised form.

  - all :: Enable all of the other debug options (but *help*).

  - help :: Explain the debugging options.

- -Olevel :: Enables query optimisation. The *find* program reorders
  tests to speed up execution while preserving the overall effect; that
  is, predicates with side effects are not reordered relative to each
  other. The optimisations performed at each optimisation level are as
  follows.

  0. Equivalent to optimisation level 1.

  1. This is the default optimisation level and corresponds to the
     traditional behaviour. Expressions are reordered so that tests
     based only on the names of files (for example *-name* and *-regex*)
     are performed first.

  2. Any *-type* or *-xtype* tests are performed after any tests based
     only on the names of files, but before any tests that require
     information from the inode. On many modern versions of Unix, file
     types are returned by *readdir()* and so these predicates are
     faster to evaluate than predicates which need to stat the file
     first. If you use the *-fstype /FOO/* predicate and specify a
     filesystem type /FOO/ which is not known (that is, present in
     `/etc/mtab') at the time *find* starts, that predicate is
     equivalent to *-false*.

  3. At this optimisation level, the full cost-based query optimiser is
     enabled. The order of tests is modified so that cheap (i.e. fast)
     tests are performed first and more expensive ones are performed
     later, if necessary. Within each cost band, predicates are
     evaluated earlier or later according to whether they are likely to
     succeed or not. For *-o*, predicates which are likely to succeed
     are evaluated earlier, and for *-a*, predicates which are likely to
     fail are evaluated earlier.

  The cost-based optimiser has a fixed idea of how likely any given test
  is to succeed. In some cases the probability takes account of the
  specific nature of the test (for example, *-type f* is assumed to be
  more likely to succeed than *-type c*). The cost-based optimiser is
  currently being evaluated. If it does not actually improve the
  performance of *find*, it will be removed again. Conversely,
  optimisations that prove to be reliable, robust and effective may be
  enabled at lower optimisation levels over time. However, the default
  behaviour (i.e. optimisation level 1) will not be changed in the 4.3.x
  release series. The findutils test suite runs all the tests on *find*
  at each optimisation level and ensures that the result is the same.

* EXPRESSION
The part of the command line after the list of starting points is the
/expression/. This is a kind of query specification describing how we
match files and what we do with the files that were matched. An
expression is composed of a sequence of things:

- Tests :: Tests return a true or false value, usually on the basis of
  some property of a file we are considering. The *-empty* test for
  example is true only when the current file is empty.

- Actions :: Actions have side effects (such as printing something on
  the standard output) and return either true or false, usually based on
  whether or not they are successful. The *-print* action for example
  prints the name of the current file on the standard output.

- Global options :: Global options affect the operation of tests and
  actions specified on any part of the command line. Global options
  always return true. The *-depth* option for example makes *find*
  traverse the file system in a depth-first order.

- Positional options :: Positional options affect only tests or actions
  which follow them. Positional options always return true. The
  *-regextype* option for example is positional, specifying the regular
  expression dialect for regular expressions occurring later on the
  command line.

- Operators :: Operators join together the other items within the
  expression. They include for example *-o* (meaning logical OR) and
  *-a* (meaning logical AND). Where an operator is missing, *-a* is
  assumed.

The *-print* action is performed on all files for which the whole
expression is true, unless it contains an action other than *-prune* or
*-quit*. Actions which inhibit the default *-print* are *-delete*,
*-exec*, *-execdir*, *-ok*, *-okdir*, *-fls*, *-fprint*, *-fprintf*,
*-ls*, *-print* and *-printf*.

The *-delete* action also acts like an option (since it implies
*-depth*).

** POSITIONAL OPTIONS
Positional options always return true. They affect only tests occurring
later on the command line.

- -daystart :: Measure times (for *-amin*, *-atime*, *-cmin*, *-ctime*,
  *-mmin*, and *-mtime*) from the beginning of today rather than from 24
  hours ago. This option only affects tests which appear later on the
  command line.

- -follow :: Deprecated; use the *-L* option instead. Dereference
  symbolic links. Implies *-noleaf*. The *-follow* option affects only
  those tests which appear after it on the command line. Unless the *-H*
  or *-L* option has been specified, the position of the *-follow*
  option changes the behaviour of the *-newer* predicate; any files
  listed as the argument of *-newer* will be dereferenced if they are
  symbolic links. The same consideration applies to *-newerXY*,
  *-anewer* and *-cnewer*. Similarly, the *-type* predicate will always
  match against the type of the file that a symbolic link points to
  rather than the link itself. Using *-follow* causes the *-lname and*
  *-ilname* predicates always to return false.

- -regextype type :: Changes the regular expression syntax understood by
  *-regex* and *-iregex* tests which occur later on the command line. To
  see which regular expression types are known, use *-regextype help*.
  The Texinfo documentation (see *SEE* *ALSO*) explains the meaning of
  and differences between the various types of regular expression.

- -warn, -nowarn :: Turn warning messages on or off. These warnings
  apply only to the command line usage, not to any conditions that
  *find* might encounter when it searches directories. The default
  behaviour corresponds to *-warn* if standard input is a tty, and to
  *-nowarn* otherwise. If a warning message relating to command-line
  usage is produced, the exit status of *find* is not affected. If the
  POSIXLY_CORRECT environment variable is set, and *-warn* is also used,
  it is not specified which, if any, warnings will be active.

** GLOBAL OPTIONS
Global options always return true. Global options take effect even for
tests which occur earlier on the command line. To prevent confusion,
global options should specified on the command-line after the list of
start points, just before the first test, positional option or action.
If you specify a global option in some other place, *find* will issue a
warning message explaining that this can be confusing.

The global options occur after the list of start points, and so are not
the same kind of option as *-L*, for example.

- -d :: A synonym for -depth, for compatibility with FreeBSD, NetBSD,
  MacOS X and OpenBSD.

- -depth :: Process each directory's contents before the directory
  itself. The -delete action also implies *-depth*.

- -help, --help :: Print a summary of the command-line usage of *find*
  and exit.

- -ignore_readdir_race :: Normally, *find* will emit an error message
  when it fails to stat a file. If you give this option and a file is
  deleted between the time *find* reads the name of the file from the
  directory and the time it tries to stat the file, no error message
  will be issued. This also applies to files or directories whose names
  are given on the command line. This option takes effect at the time
  the command line is read, which means that you cannot search one part
  of the filesystem with this option on and part of it with this option
  off (if you need to do that, you will need to issue two *find*
  commands instead, one with the option and one without it).

Furthermore, *find* with the *-ignore_readdir_race* option will ignore
errors of the *-delete* action in the case the file has disappeared
since the parent directory was read: it will not output an error
diagnostic, and the return code of the *-delete* action will be true.

- -maxdepth levels :: Descend at most /levels/ (a non-negative integer)
  levels of directories below the starting-points. Using *-maxdepth 0*
  means only apply the tests and actions to the starting-points
  themselves.

- -mindepth levels :: Do not apply any tests or actions at levels less
  than /levels/ (a non-negative integer). Using *-mindepth 1* means
  process all files except the starting-points.

- -mount :: Don't descend directories on other filesystems. An alternate
  name for *-xdev*, for compatibility with some other versions of
  *find*.

- -noignore_readdir_race :: Turns off the effect of
  *-ignore_readdir_race*.

- -noleaf :: Do not optimize by assuming that directories contain 2
  fewer subdirectories than their hard link count. This option is needed
  when searching filesystems that do not follow the Unix directory-link
  convention, such as CD-ROM or MS-DOS filesystems or AFS volume mount
  points. Each directory on a normal Unix filesystem has at least 2 hard
  links: its name and its `.' entry. Additionally, its subdirectories
  (if any) each have a `..' entry linked to that directory. When *find*
  is examining a directory, after it has statted 2 fewer subdirectories
  than the directory's link count, it knows that the rest of the entries
  in the directory are non-directories (`leaf' files in the directory
  tree). If only the files' names need to be examined, there is no need
  to stat them; this gives a significant increase in search speed.

- -version, --version :: Print the *find* version number and exit.

- -xdev :: Don't descend directories on other filesystems.

** TESTS
Some tests, for example *-newerXY* and *-samefile*, allow comparison
between the file currently being examined and some reference file
specified on the command line. When these tests are used, the
interpretation of the reference file is determined by the options *-H*,
*-L* and *-P* and any previous *-follow*, but the reference file is only
examined once, at the time the command line is parsed. If the reference
file cannot be examined (for example, the *stat*(2) system call fails
for it), an error message is issued, and *find* exits with a nonzero
status.

A numeric argument /n/ can be specified to tests (like *-amin*,
*-mtime*, *-gid*, *-inum*, *-links*, *-size*, *-uid* and *-used*) as

- +n :: for greater than /n/,

- -n :: for less than /n/,

14. for exactly /n/.

Supported tests:

- -amin n :: File was last accessed less than, more than or exactly /n/
  minutes ago.

- -anewer reference :: Time of the last access of the current file is
  more recent than that of the last data modification of the /reference/
  file. If /reference/ is a symbolic link and the *-H* option or the
  *-L* option is in effect, then the time of the last data modification
  of the file it points to is always used.

- -atime n :: File was last accessed less than, more than or exactly
  /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.

- -cmin n :: File's status was last changed less than, more than or
  exactly /n/ minutes ago.

- -cnewer reference :: Time of the last status change of the current
  file is more recent than that of the last data modification of the
  /reference/ file. If /reference/ is a symbolic link and the *-H*
  option or the *-L* option is in effect, then the time of the last data
  modification of the file it points to is always used.

- -ctime n :: File's status was last changed less than, more than or
  exactly /n/*24 hours ago. See the comments for *-atime* to understand
  how rounding affects the interpretation of file status change times.

- -empty :: File is empty and is either a regular file or a directory.

- -executable :: Matches files which are executable and directories
  which are searchable (in a file name resolution sense) by the current
  user. This takes into account access control lists and other
  permissions artefacts which the *-perm* test ignores. This test makes
  use of the *access*(2) system call, and so can be fooled by NFS
  servers which do UID mapping (or root-squashing), since many systems
  implement *access*(2) in the client's kernel and so cannot make use of
  the UID mapping information held on the server. Because this test is
  based only on the result of the *access*(2) system call, there is no
  guarantee that a file for which this test succeeds can actually be
  executed.

- -false :: Always false.

- -fstype type :: File is on a filesystem of type /type/. The valid
  filesystem types vary among different versions of Unix; an incomplete
  list of filesystem types that are accepted on some version of Unix or
  another is: ufs, 4.2, 4.3, nfs, tmp, mfs, S51K, S52K. You can use
  *-printf* with the %F directive to see the types of your filesystems.

- -gid n :: File's numeric group ID is less than, more than or exactly
  /n/.

- -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. The pattern `*foo*` will also match a file
  called '.foobar'.

- -inum n :: File has inode number smaller than, greater than or exactly
  /n/. It is normally easier to use the *-samefile* test instead.

- -ipath pattern :: Like *-path*. but the match is case insensitive.

- -iregex pattern :: Like *-regex*, but the match is case insensitive.

- -iwholename pattern :: See -ipath. This alternative is less portable
  than *-ipath*.

- -links n :: File has less than, more than or exactly /n/ hard links.

- -lname pattern :: File is a symbolic link whose contents match shell
  pattern /pattern/. The metacharacters do not treat `/' or `.'
  specially. If the *-L* option or the *-follow* option is in effect,
  this test returns false unless the symbolic link is broken.

- -mmin n :: File's data was last modified less than, more than or
  exactly /n/ minutes ago.

- -mtime n :: File's data was last modified less than, more than or
  exactly /n/*24 hours ago. See the comments for *-atime* to understand
  how rounding affects the interpretation of file modification times.

- -name pattern :: Base of file name (the path with the leading
  directories removed) matches shell pattern /pattern/. Because the
  leading directories are removed, the file names considered for a match
  with *-name* will never include a slash, so `-name a/b' will never
  match anything (you probably need to use *-path* instead). A warning
  is issued if you try to do this, unless the environment variable
  POSIXLY_CORRECT is set. The metacharacters (`*', `?', and `[]') match
  a `.' at the start of the base name (this is a change in
  findutils-4.2.2; see section STANDARDS CONFORMANCE below). To ignore a
  directory and the files under it, use *-prune* rather than checking
  every file in the tree; see an example in the description of that
  action. 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.

- -newer reference :: Time of the last data modification of the current
  file is more recent than that of the last data modification of the
  /reference/ file. If /reference/ is a symbolic link and the *-H*
  option or the *-L* option is in effect, then the time of the last data
  modification of the file it points to is always used.

- -newerXY reference :: Succeeds if timestamp /X/ of the file being
  considered is newer than timestamp /Y/ of the file /reference/. The
  letters /X/ and /Y/ can be any of the following letters:

| a | The access time of the file /reference/       |
| B | The birth time of the file /reference/        |
| c | The inode status change time of /reference/   |
| m | The modification time of the file /reference/ |
| t | /reference/ is interpreted directly as a time |

Some combinations are invalid; for example, it is invalid for /X/ to be
/t/. Some combinations are not implemented on all systems; for example
/B/ is not supported on all systems. If an invalid or unsupported
combination of /XY/ is specified, a fatal error results. Time
specifications are interpreted as for the argument to the *-d* option of
GNU *date*. If you try to use the birth time of a reference file, and
the birth time cannot be determined, a fatal error message results. If
you specify a test which refers to the birth time of files being
examined, this test will fail for any files where the birth time is
unknown.

- -nogroup :: No group corresponds to file's numeric group ID.

- -nouser :: No user corresponds to file's numeric user ID.

- -path pattern :: File name matches shell pattern /pattern/. The
  metacharacters do not treat `/' or `.' specially; so, for example,

#+begin_example
  find . -path "./sr*sc"
#+end_example

will print an entry for a directory called /./src/misc/ (if one exists).
To ignore a whole directory tree, use *-prune* rather than checking
every file in the tree. Note that the pattern match test applies to the
whole file name, starting from one of the start points named on the
command line. It would only make sense to use an absolute path name here
if the relevant start point is also an absolute path. This means that
this command will never match anything:\\

#+begin_example
  find bar -path /foo/bar/myfile -print
#+end_example

Find compares the *-path* argument with the concatenation of a directory
name and the base name of the file it's examining. Since the
concatenation will never end with a slash, *-path* arguments ending in a
slash will match nothing (except perhaps a start point specified on the
command line). The predicate *-path* is also supported by HP-UX *find*
and is part of the POSIX 2008 standard.

- -perm mode :: File's permission bits are exactly /mode/ (octal or
  symbolic). Since an exact match is required, if you want to use this
  form for symbolic modes, you may have to specify a rather complex mode
  string. For example `-perm g=w' will only match files which have mode
  0020 (that is, ones for which group write permission is the only
  permission set). It is more likely that you will want to use the `/'
  or `-' forms, for example `-perm -g=w', which matches any file with
  group write permission. See the *EXAMPLES* section for some
  illustrative examples.

- -perm -mode :: All of the permission bits /mode/ are set for the file.
  Symbolic modes are accepted in this form, and this is usually the way
  in which you would want to use them. You must specify `u', `g' or `o'
  if you use a symbolic mode. See the *EXAMPLES* section for some
  illustrative examples.

- -perm /mode :: Any of the permission bits /mode/ are set for the file.
  Symbolic modes are accepted in this form. You must specify `u', `g' or
  `o' if you use a symbolic mode. See the *EXAMPLES* section for some
  illustrative examples. If no permission bits in /mode/ are set, this
  test matches any file (the idea here is to be consistent with the
  behaviour of *-perm -000*).

- -perm +mode :: This is no longer supported (and has been deprecated
  since 2005). Use *-perm //mode/* instead.

- -readable :: Matches files which are readable by the current user.
  This takes into account access control lists and other permissions
  artefacts which the *-perm* test ignores. This test makes use of the
  *access*(2) system call, and so can be fooled by NFS servers which do
  UID mapping (or root-squashing), since many systems implement
  *access*(2) in the client's kernel and so cannot make use of the UID
  mapping information held on the server.

- -regex pattern :: File name matches regular expression /pattern/. This
  is a match on the whole path, not a search. For example, to match a
  file named /./fubar3,/ you can use the regular expression `.*bar.' or
  `.*b.*3', but not `f.*r3'. The regular expressions understood by
  *find* are by default Emacs Regular Expressions (except that `.'
  matches newline), but this can be changed with the *-regextype*
  option.

- -samefile name :: File refers to the same inode as /name/. When *-L*
  is in effect, this can include symbolic links.

- -size n[cwbkMG] :: File uses less than, more than or exactly /n/ units
  of space, rounding up. The following suffixes can be used:

  - `b' :: for 512-byte blocks (this is the default if no suffix is
    used)

  - `c' :: for bytes

  - `w' :: for two-byte words

  - `k' :: for kibibytes (KiB, units of 1024 bytes)

  - `M' :: for mebibytes (MiB, units of 1024 * 1024 = 1 048 576 bytes)

  - `G' :: for gibibytes (GiB, units of 1024 * 1024 * 1024 =
    1 073 741 824 bytes)

  The size is simply the st_size member of the struct stat populated by
  the lstat (or stat) system call, rounded up as shown above. In other
  words, it's consistent with the result you get for *ls -l*. Bear in
  mind that the `%k' and `%b' format specifiers of *-printf* handle
  sparse files differently. The `b' suffix always denotes 512-byte
  blocks and never 1024-byte blocks, which is different to the behaviour
  of *-ls*.

  The + and - prefixes signify greater than and less than, as usual;
  i.e., an exact size of /n/ units does not match. Bear in mind that the
  size is rounded up to the next unit. Therefore *-size -1M* is not
  equivalent to *-size -1 048 576c*. The former only matches empty
  files, the latter matches files from 0 to 1,048,575 bytes.

- -true :: Always true.

- -type c :: File is of type /c/:

  2. block (buffered) special

  3. character (unbuffered) special

  4. directory

  5. named pipe (FIFO)

  6. regular file

  7. symbolic link; this is never true if the *-L* option or the
     *-follow* option is in effect, unless the symbolic link is broken.
     If you want to search for symbolic links when *-L* is in effect,
     use *-xtype*.

  8. socket

  4. door (Solaris)

  To search for more than one type at once, you can supply the combined
  list of type letters separated by a comma `,' (GNU extension).

- -uid n :: File's numeric user ID is less than, more than or exactly
  /n/.

- -used n :: File was last accessed less than, more than or exactly /n/
  days after its status was last changed.

- -user uname :: File is owned by user /uname/ (numeric user ID
  allowed).

- -wholename pattern :: See -path. This alternative is less portable
  than *-path*.

- -writable :: Matches files which are writable by the current user.
  This takes into account access control lists and other permissions
  artefacts which the *-perm* test ignores. This test makes use of the
  *access*(2) system call, and so can be fooled by NFS servers which do
  UID mapping (or root-squashing), since many systems implement
  *access*(2) in the client's kernel and so cannot make use of the UID
  mapping information held on the server.

- -xtype c :: The same as *-type* unless the file is a symbolic link.
  For symbolic links: if the *-H* or *-P* option was specified, true if
  the file is a link to a file of type /c/; if the *-L* option has been
  given, true if /c/ is `l'. In other words, for symbolic links,
  *-xtype* checks the type of the file that *-type* does not check.

- -context pattern :: (SELinux only) Security context of the file
  matches glob /pattern/.

** ACTIONS
- -delete :: Delete files; true if removal succeeded. If the removal
  failed, an error message is issued. If *-delete* fails, *find*'s exit
  status will be nonzero (when it eventually exits). Use of *-delete*
  automatically turns on the `*-depth*' option.

*Warnings*: Don't forget that the find command line is evaluated as an
expression, so putting *-delete* first will make *find* try to delete
everything below the starting points you specified. When testing a
*find* command line that you later intend to use with *-delete*, you
should explicitly specify *-depth* in order to avoid later surprises.
Because *-delete* implies *-depth*, you cannot usefully use *-prune* and
*-delete* together.

Together with the *-ignore_readdir_race* option, *find* will ignore
errors of the *-delete* action in the case the file has disappeared
since the parent directory was read: it will not output an error
diagnostic, and the return code of the *-delete* action will be true.

- -exec command ; :: Execute /command/; true if 0 status is returned.
  All following arguments to *find* are taken to be arguments to the
  command until an argument consisting of `;' is encountered. The string
  `{}' is replaced by the current file name being processed everywhere
  it occurs in the arguments to the command, not just in arguments where
  it is alone, as in some versions of *find*. Both of these
  constructions might need to be escaped (with a `\') or quoted to
  protect them from expansion by the shell. See the *EXAMPLES* section
  for examples of the use of the *-exec* option. The specified command
  is run once for each matched file. The command is executed in the
  starting directory. There are unavoidable security problems
  surrounding use of the *-exec* action; you should use the *-execdir*
  option instead.

- -exec command {} + :: This variant of the *-exec* action runs the
  specified command on the selected files, but the command line is built
  by appending each selected file name at the end; the total number of
  invocations of the command will be much less than the number of
  matched files. The command line is built in much the same way that
  *xargs* builds its command lines. Only one instance of `{}' is allowed
  within the command, and it must appear at the end, immediately before
  the `+'; it needs to be escaped (with a `\') or quoted to protect it
  from interpretation by the shell. The command is executed in the
  starting directory. If any invocation with the `+' form returns a
  non-zero value as exit status, then *find* returns a non-zero exit
  status. If *find* encounters an error, this can sometimes cause an
  immediate exit, so some pending commands may not be run at all. For
  this reason *-exec /my-command/ ... {} + -quit* may not result in
  /my-command/ actually being run. This variant of *-exec* always
  returns true.

- -execdir command ; :: 

- -execdir command {} + :: Like *-exec*, but the specified command is
  run from the subdirectory containing the matched file, which is not
  normally the directory in which you started *find*. As with -exec, the
  {} should be quoted if find is being invoked from a shell. This a much
  more secure method for invoking commands, as it avoids race conditions
  during resolution of the paths to the matched files. As with the
  *-exec* action, the `+' form of *-execdir* will build a command line
  to process more than one matched file, but any given invocation of
  /command/ will only list files that exist in the same subdirectory. If
  you use this option, you must ensure that your *$PATH* environment
  variable does not reference `.'; otherwise, an attacker can run any
  commands they like by leaving an appropriately-named file in a
  directory in which you will run *-execdir*. The same applies to having
  entries in *$PATH* which are empty or which are not absolute directory
  names. If any invocation with the `+' form returns a non-zero value as
  exit status, then *find* returns a non-zero exit status. If *find*
  encounters an error, this can sometimes cause an immediate exit, so
  some pending commands may not be run at all. The result of the action
  depends on whether the *+* or the *;* variant is being used; *-execdir
  /command/ {} +* always returns true, while *-execdir /command/ {} ;*
  returns true only if /command/ returns 0.

- -fls file :: True; like *-ls* but write to /file/ like *-fprint*. The
  output file is always created, even if the predicate is never matched.
  See the *UNUSUAL FILENAMES* section for information about how unusual
  characters in filenames are handled.

- -fprint file :: True; print the full file name into file /file/. If
  /file/ does not exist when *find* is run, it is created; if it does
  exist, it is truncated. The file names //dev/stdout/ and //dev/stderr/
  are handled specially; they refer to the standard output and standard
  error output, respectively. The output file is always created, even if
  the predicate is never matched. See the *UNUSUAL FILENAMES* section
  for information about how unusual characters in filenames are handled.

- -fprint0 file :: True; like *-print0* but write to /file/ like
  *-fprint*. The output file is always created, even if the predicate is
  never matched. See the *UNUSUAL FILENAMES* section for information
  about how unusual characters in filenames are handled.

- -fprintf file format :: True; like *-printf* but write to /file/ like
  *-fprint*. The output file is always created, even if the predicate is
  never matched. See the *UNUSUAL FILENAMES* section for information
  about how unusual characters in filenames are handled.

- -ls :: True; list current file in *ls -dils* format on standard
  output. The block counts are of 1 KB blocks, unless the environment
  variable POSIXLY_CORRECT is set, in which case 512-byte blocks are
  used. See the *UNUSUAL FILENAMES* section for information about how
  unusual characters in filenames are handled.

- -ok command ; :: Like *-exec* but ask the user first. If the user
  agrees, run the command. Otherwise just return false. If the command
  is run, its standard input is redirected from //dev/null/.

  The response to the prompt is matched against a pair of regular
  expressions to determine if it is an affirmative or negative response.
  This regular expression is obtained from the system if the
  `POSIXLY_CORRECT' environment variable is set, or otherwise from
  *find*'s message translations. If the system has no suitable
  definition, *find*'s own definition will be used. In either case, the
  interpretation of the regular expression itself will be affected by
  the environment variables 'LC_CTYPE' (character classes) and
  'LC_COLLATE' (character ranges and equivalence classes).

- -okdir command ; :: Like *-execdir* but ask the user first in the same
  way as for *-ok*. If the user does not agree, just return false. If
  the command is run, its standard input is redirected from //dev/null/.

- -print :: True; print the full file name on the standard output,
  followed by a newline. If you are piping the output of *find* into
  another program and there is the faintest possibility that the files
  which you are searching for might contain a newline, then you should
  seriously consider using the *-print0* option instead of *-print*. See
  the *UNUSUAL FILENAMES* section for information about how unusual
  characters in filenames are handled.

- -print0 :: True; print the full file name on the standard output,
  followed by a null character (instead of the newline character that
  *-print* uses). This allows file names that contain newlines or other
  types of white space to be correctly interpreted by programs that
  process the *find* output. This option corresponds to the *-0* option
  of *xargs*.

- -printf format :: True; print /format/ on the standard output,
  interpreting `\' escapes and `%' directives. Field widths and
  precisions can be specified as with the *printf*(3) C function. Please
  note that many of the fields are printed as %s rather than %d, and
  this may mean that flags don't work as you might expect. This also
  means that the `-' flag does work (it forces fields to be
  left-aligned). Unlike *-print*, *-printf* does not add a newline at
  the end of the string. The escapes and directives are:

  - \a :: Alarm bell.

  - \b :: Backspace.

  - \c :: Stop printing from this format immediately and flush the
    output.

  - \f :: Form feed.

  - \n :: Newline.

  - \r :: Carriage return.

  - \t :: Horizontal tab.

  - \v :: Vertical tab.

  - \0 :: ASCII NUL.

  - \\ :: A literal backslash (`\').

  - \NNN :: The character whose ASCII code is NNN (octal).

  A `\' character followed by any other character is treated as an
  ordinary character, so they both are printed.

  - %% :: A literal percent sign.

  - %a :: File's last access time in the format returned by the C
    *ctime*(3) function.

  - %Ak :: File's last access time in the format specified by /k/, which
    is either `@' or a directive for the C *strftime*(3) function. The
    following shows an incomplete list of possible values for /k/.
    Please refer to the documentation of *strftime*(3) for the full
    list. Some of the conversion specification characters might not be
    available on all systems, due to differences in the implementation
    of the *strftime*(3) library function.

    1. seconds since Jan. 1, 1970, 00:00 GMT, with fractional part.

    Time fields:

    8. hour (00..23)

    1. hour (01..12)

    11. hour ( 0..23)

    12. hour ( 1..12)

    13. minute (00..59)

    16. locale's AM or PM

    17. time, 12-hour (hh:mm:ss [AP]M)

    19. Second (00.00 .. 61.00). There is a fractional part.

    20. time, 24-hour (hh:mm:ss.xxxxxxxxxx)

    - Date and time, separated by `+', for example
      `2004-04-28+22:22:05.0'. This is a GNU extension. The time is
      given in the current timezone (which may be affected by setting
      the TZ environment variable). The seconds field includes a
      fractional part.

    24. locale's time representation (H:M:S). The seconds field includes
        a fractional part.

    25. time zone (e.g., EDT), or nothing if no time zone is
        determinable

    Date fields:

    1. locale's abbreviated weekday name (Sun..Sat)

    1. locale's full weekday name, variable length (Sunday..Saturday)

    2. locale's abbreviated month name (Jan..Dec)

    2. locale's full month name, variable length (January..December)

    3. locale's date and time (Sat Nov 04 12:02:33 EST 1989). The format
       is the same as for *ctime*(3) and so to preserve compatibility
       with that format, there is no fractional part in the seconds
       field.

    4. day of month (01..31)

    4. date (mm/dd/yy)

    5. date (yyyy-mm-dd)

    8.  same as b

    9.  day of year (001..366)

    10. month (01..12)

    21. week number of year with Sunday as first day of week (00..53)

    23. day of week (0..6)

    23. week number of year with Monday as first day of week (00..53)

    24. locale's date representation (mm/dd/yy)

    25. last two digits of year (00..99)

    25. year (1970...)

  - %b :: The amount of disk space used for this file in 512-byte
    blocks. Since disk space is allocated in multiples of the filesystem
    block size this is usually greater than %s/512, but it can also be
    smaller if the file is a sparse file.

  - %c :: File's last status change time in the format returned by the C
    *ctime*(3) function.

  - %Ck :: File's last status change time in the format specified by
    /k/, which is the same as for %A.

  - %d :: File's depth in the directory tree; 0 means the file is a
    starting-point.

  - %D :: The device number on which the file exists (the st_dev field
    of struct stat), in decimal.

  - %f :: Print the basename; the file's name with any leading
    directories removed (only the last element). For */*, the result is
    `/'. See the *EXAMPLES* section for an example.

  - %F :: Type of the filesystem the file is on; this value can be used
    for -fstype.

  - %g :: File's group name, or numeric group ID if the group has no
    name.

  - %G :: File's numeric group ID.

  - %h :: Dirname; the Leading directories of the file's name (all but
    the last element). If the file name contains no slashes (since it is
    in the current directory) the %h specifier expands to `.'. For files
    which are themselves directories and contain a slash (including
    */*), %h expands to the empty string. See the *EXAMPLES* section for
    an example.

  - %H :: Starting-point under which file was found.

  - %i :: File's inode number (in decimal).

  - %k :: The amount of disk space used for this file in 1 KB blocks.
    Since disk space is allocated in multiples of the filesystem block
    size this is usually greater than %s/1024, but it can also be
    smaller if the file is a sparse file.

  - %l :: Object of symbolic link (empty string if file is not a
    symbolic link).

  - %m :: File's permission bits (in octal). This option uses the
    `traditional' numbers which most Unix implementations use, but if
    your particular implementation uses an unusual ordering of octal
    permissions bits, you will see a difference between the actual value
    of the file's mode and the output of %m. Normally you will want to
    have a leading zero on this number, and to do this, you should use
    the *#* flag (as in, for example, `%#m').

  - %M :: File's permissions (in symbolic form, as for *ls*). This
    directive is supported in findutils 4.2.5 and later.

  - %n :: Number of hard links to file.

  - %p :: File's name.

  - %P :: File's name with the name of the starting-point under which it
    was found removed.

  - %s :: File's size in bytes.

  - %S :: File's sparseness. This is calculated as (BLOCKSIZE*st_blocks
    / st_size). The exact value you will get for an ordinary file of a
    certain length is system-dependent. However, normally sparse files
    will have values less than 1.0, and files which use indirect blocks
    may have a value which is greater than 1.0. In general the number of
    blocks used by a file is file system dependent. The value used for
    BLOCKSIZE is system-dependent, but is usually 512 bytes. If the file
    size is zero, the value printed is undefined. On systems which lack
    support for st_blocks, a file's sparseness is assumed to be 1.0.

  - %t :: File's last modification time in the format returned by the C
    *ctime*(3) function.

  - %Tk :: File's last modification time in the format specified by /k/,
    which is the same as for %A.

  - %u :: File's user name, or numeric user ID if the user has no name.

  - %U :: File's numeric user ID.

  - %y :: File's type (like in *ls -l*), U=unknown type (shouldn't
    happen)

  - %Y :: File's type (like %y), plus follow symbolic links: `L'=loop,
    `N'=nonexistent, `?' for any other error when determining the type
    of the target of a symbolic link.

  - %Z :: (SELinux only) file's security context.

  - %{ %[ %( :: Reserved for future use.

  A `%' character followed by any other character is discarded, but the
  other character is printed (don't rely on this, as further format
  characters may be introduced). A `%' at the end of the format argument
  causes undefined behaviour since there is no following character. In
  some locales, it may hide your door keys, while in others it may
  remove the final page from the novel you are reading.

  The %m and %d directives support the *#*, *0* and *+* flags, but the
  other directives do not, even if they print numbers. Numeric
  directives that do not support these flags include *G*, *U*, *b*, *D*,
  *k* and *n*. The `-' format flag is supported and changes the
  alignment of a field from right-justified (which is the default) to
  left-justified.

  See the *UNUSUAL FILENAMES* section for information about how unusual
  characters in filenames are handled.

- -prune :: True; if the file is a directory, do not descend into it. If
  *-depth* is given, then *-prune* has no effect. Because *-delete*
  implies *-depth*, you cannot usefully use *-prune* and *-delete*
  together. For example, to skip the directory /src/emacs/ and all files
  and directories under it, and print the names of the other files
  found, do something like this:

#+begin_example
  find . -path ./src/emacs -prune -o -print
#+end_example

- -quit :: Exit immediately (with return value zero if no errors have
  occurred). This is different to *-prune* because *-prune* only applies
  to the contents of pruned directories, while *-quit* simply makes
  *find* stop immediately. No child processes will be left running. Any
  command lines which have been built by *-exec ... +* or *-execdir ...
  +* are invoked before the program is exited. After *-quit* is
  executed, no more files specified on the command line will be
  processed. For example, `*find //tmp/foo/ //tmp/bar/ -print -quit*`
  will print only `/tmp/foo`.\\
  One common use of *-quit* is to stop searching the file system once we
  have found what we want. For example, if we want to find just a single
  file we can do this:

#+begin_example
  find / -name needle -print -quit
#+end_example

** OPERATORS
Listed in order of decreasing precedence:

- ( expr ) :: Force precedence. Since parentheses are special to the
  shell, you will normally need to quote them. Many of the examples in
  this manual page use backslashes for this purpose: `\(...\)' instead
  of `(...)'.

- ! expr :: True if /expr/ is false. This character will also usually
  need protection from interpretation by the shell.

- -not expr :: Same as ! /expr/, but not POSIX compliant.

- expr1 expr2 :: Two expressions in a row are taken to be joined with an
  implied *-a*; /expr2/ is not evaluated if /expr1/ is false.

- expr1 -a expr2 :: Same as /expr1 expr2/.

- expr1 -and expr2 :: Same as /expr1 expr2/, but not POSIX compliant.

- expr1 -o expr2 :: Or; /expr2/ is not evaluated if /expr1/ is true.

- expr1 -or expr2 :: Same as /expr1/ *-o* /expr2/, but not POSIX
  compliant.

- expr1 , expr2 :: List; both /expr1/ and /expr2/ are always evaluated.
  The value of /expr1/ is discarded; the value of the list is the value
  of /expr2/. The comma operator can be useful for searching for several
  different types of thing, but traversing the filesystem hierarchy only
  once. The *-fprintf* action can be used to list the various matched
  items into several different output files.

Please note that *-a* when specified implicitly (for example by two
tests appearing without an explicit operator between them) or explicitly
has higher precedence than *-o*. This means that *find . -name afile -o
-name bfile -print* will never print /afile/.

* UNUSUAL FILENAMES
Many of the actions of *find* result in the printing of data which is
under the control of other users. This includes file names, sizes,
modification times and so forth. File names are a potential problem
since they can contain any character except `\0' and `/'. Unusual
characters in file names can do unexpected and often undesirable things
to your terminal (for example, changing the settings of your function
keys on some terminals). Unusual characters are handled differently by
various actions, as described below.

- -print0, -fprint0 :: Always print the exact filename, unchanged, even
  if the output is going to a terminal.

- -ls, -fls :: Unusual characters are always escaped. White space,
  backslash, and double quote characters are printed using C-style
  escaping (for example `\f', `\"'). Other unusual characters are
  printed using an octal escape. Other printable characters (for *-ls*
  and *-fls* these are the characters between octal 041 and 0176) are
  printed as-is.

- -printf, -fprintf :: If the output is not going to a terminal, it is
  printed as-is. Otherwise, the result depends on which directive is in
  use. The directives %D, %F, %g, %G, %H, %Y, and %y expand to values
  which are not under control of files' owners, and so are printed
  as-is. The directives %a, %b, %c, %d, %i, %k, %m, %M, %n, %s, %t, %u
  and %U have values which are under the control of files' owners but
  which cannot be used to send arbitrary data to the terminal, and so
  these are printed as-is. The directives %f, %h, %l, %p and %P are
  quoted. This quoting is performed in the same way as for GNU *ls*.
  This is not the same quoting mechanism as the one used for *-ls* and
  *-fls*. If you are able to decide what format to use for the output of
  *find* then it is normally better to use `\0' as a terminator than to
  use newline, as file names can contain white space and newline
  characters. The setting of the `LC_CTYPE' environment variable is used
  to determine which characters need to be quoted.

- -print, -fprint :: Quoting is handled in the same way as for *-printf*
  and *-fprintf*. If you are using *find* in a script or in a situation
  where the matched files might have arbitrary names, you should
  consider using *-print0* instead of *-print*.

The *-ok* and *-okdir* actions print the current filename as-is. This
may change in a future release.

* STANDARDS CONFORMANCE
For closest compliance to the POSIX standard, you should set the
POSIXLY_CORRECT environment variable. The following options are
specified in the POSIX standard (IEEE Std 1003.1-2008, 2016 Edition):

- -H :: This option is supported.

- -L :: This option is supported.

- -name :: This option is supported, but POSIX conformance depends on
  the POSIX conformance of the system's *fnmatch*(3) library function.
  As of findutils-4.2.2, shell metacharacters (`*', `?' or `[]' for
  example) match a leading `.', because IEEE PASC interpretation 126
  requires this. This is a change from previous versions of findutils.

- -type :: Supported. POSIX specifies `b', `c', `d', `l', `p', `f' and
  `s'. GNU find also supports `D', representing a Door, where the OS
  provides these. Furthermore, GNU find allows multiple types to be
  specified at once in a comma-separated list.

- -ok :: Supported. Interpretation of the response is according to the
  `yes' and `no' patterns selected by setting the `LC_MESSAGES'
  environment variable. When the `POSIXLY_CORRECT' environment variable
  is set, these patterns are taken system's definition of a positive
  (yes) or negative (no) response. See the system's documentation for
  *nl_langinfo*(3), in particular YESEXPR and NOEXPR. When
  `POSIXLY_CORRECT' is not set, the patterns are instead taken from
  *find*'s own message catalogue.

- -newer :: Supported. If the file specified is a symbolic link, it is
  always dereferenced. This is a change from previous behaviour, which
  used to take the relevant time from the symbolic link; see the HISTORY
  section below.

- -perm :: Supported. If the POSIXLY_CORRECT environment variable is not
  set, some mode arguments (for example +a+x) which are not valid in
  POSIX are supported for backward-compatibility.

- Other primaries :: The primaries *-atime*, *-ctime*, *-depth*,
  *-exec*, *-group*, *-links*, *-mtime*, *-nogroup*, *-nouser*, *-ok*,
  *-path*, *-print*, *-prune*, *-size*, *-user* and *-xdev* are all
  supported.

The POSIX standard specifies parentheses `(', `)', negation `!' and the
logical AND/OR operators *-a* and *-o*.

All other options, predicates, expressions and so forth are extensions
beyond the POSIX standard. Many of these extensions are not unique to
GNU find, however.

The POSIX standard requires that *find* detects loops:

#+begin_quote
  The *find* utility shall detect infinite loops; that is, entering a
  previously visited directory that is an ancestor of the last file
  encountered. When it detects an infinite loop, find shall write a
  diagnostic message to standard error and shall either recover its
  position in the hierarchy or terminate.
#+end_quote

GNU *find* complies with these requirements. The link count of
directories which contain entries which are hard links to an ancestor
will often be lower than they otherwise should be. This can mean that
GNU find will sometimes optimise away the visiting of a subdirectory
which is actually a link to an ancestor. Since *find* does not actually
enter such a subdirectory, it is allowed to avoid emitting a diagnostic
message. Although this behaviour may be somewhat confusing, it is
unlikely that anybody actually depends on this behaviour. If the leaf
optimisation has been turned off with *-noleaf*, the directory entry
will always be examined and the diagnostic message will be issued where
it is appropriate. Symbolic links cannot be used to create filesystem
cycles as such, but if the *-L* option or the *-follow* option is in
use, a diagnostic message is issued when *find* encounters a loop of
symbolic links. As with loops containing hard links, the leaf
optimisation will often mean that *find* knows that it doesn't need to
call /stat()/ or /chdir()/ on the symbolic link, so this diagnostic is
frequently not necessary.

The *-d* option is supported for compatibility with various BSD systems,
but you should use the POSIX-compliant option *-depth* instead.

The POSIXLY_CORRECT environment variable does not affect the behaviour
of the *-regex* or *-iregex* tests because those tests aren't specified
in the POSIX standard.

* ENVIRONMENT VARIABLES
- LANG :: Provides a default value for the internationalization
  variables that are unset or null.

- LC_ALL :: If set to a non-empty string value, override the values of
  all the other internationalization variables.

- LC_COLLATE :: The POSIX standard specifies that this variable affects
  the pattern matching to be used for the *-name* option. GNU find uses
  the *fnmatch*(3) library function, and so support for `LC_COLLATE'
  depends on the system library. This variable also affects the
  interpretation of the response to *-ok*; while the `LC_MESSAGES'
  variable selects the actual pattern used to interpret the response to
  *-ok*, the interpretation of any bracket expressions in the pattern
  will be affected by `LC_COLLATE'.

- LC_CTYPE :: This variable affects the treatment of character classes
  used in regular expressions and also with the *-name* test, if the
  system's *fnmatch*(3) library function supports this. This variable
  also affects the interpretation of any character classes in the
  regular expressions used to interpret the response to the prompt
  issued by *-ok*. The `LC_CTYPE' environment variable will also affect
  which characters are considered to be unprintable when filenames are
  printed; see the section UNUSUAL FILENAMES.

- LC_MESSAGES :: Determines the locale to be used for internationalised
  messages. If the `POSIXLY_CORRECT' environment variable is set, this
  also determines the interpretation of the response to the prompt made
  by the *-ok* action.

- NLSPATH :: Determines the location of the internationalisation message
  catalogues.

- PATH :: Affects the directories which are searched to find the
  executables invoked by *-exec*, *-execdir*, *-ok* and *-okdir*.

- POSIXLY_CORRECT :: Determines the block size used by *-ls* and *-fls*.
  If *POSIXLY_CORRECT* is set, blocks are units of 512 bytes. Otherwise
  they are units of 1024 bytes.

  Setting this variable also turns off warning messages (that is,
  implies *-nowarn*) by default, because POSIX requires that apart from
  the output for *-ok*, all messages printed on stderr are diagnostics
  and must result in a non-zero exit status.

  When POSIXLY_CORRECT is not set, *-perm /+zzz/* is treated just like
  *-perm //zzz/* if /+zzz/ is not a valid symbolic mode. When
  POSIXLY_CORRECT is set, such constructs are treated as an error.

  When POSIXLY_CORRECT is set, the response to the prompt made by the
  *-ok* action is interpreted according to the system's message
  catalogue, as opposed to according to *find*'s own message
  translations.

- TZ :: Affects the time zone used for some of the time-related format
  directives of *-printf* and *-fprintf*.

* EXAMPLES
** Simple `find|xargs` approach

- Find files named /core/ in or below the directory //tmp/ and delete
  them.

#+begin_example
  $ find /tmp -name core -type f -print | xargs /bin/rm -f
#+end_example

Note that this will work incorrectly if there are any filenames
containing newlines, single or double quotes, or spaces.

** Safer `find -print0 | xargs -0` approach

- Find files named /core/ in or below the directory //tmp/ and delete
  them, processing filenames in such a way that file or directory names
  containing single or double quotes, spaces or newlines are correctly
  handled.

#+begin_example
  $ find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f
#+end_example

The *-name* test comes before the *-type* test in order to avoid having
to call *stat(2)* on every file.

Note that there is still a race between the time *find* traverses the
hierarchy printing the matching filenames, and the time the process
executed by *xargs* works with that file.

** Executing a command for each file

- Run /file/ on every file in or below the current directory.

#+begin_example
  $ find . -type f -exec file '{}' \;
#+end_example

Notice that the braces are enclosed in single quote marks to protect
them from interpretation as shell script punctuation. The semicolon is
similarly protected by the use of a backslash, though single quotes
could have been used in that case also.

In many cases, one might prefer the *`-exec ... +`* or better the
*`-execdir ... +`* syntax for performance and security reasons.

** Traversing the filesystem just once - for 2 different actions

- Traverse the filesystem just once, listing set-user-ID files and
  directories into //root/suid.txt/ and large files into
  //root/big.txt/.

#+begin_example
  $ find / \
  \( -perm -4000 -fprintf /root/suid.txt '%#m %u %p\n' \) , \


  \( -size +100M -fprintf /root/big.txt '%-10s %p\n' \)
#+end_example

This example uses the line-continuation character '\' on the first two
lines to instruct the shell to continue reading the command on the next
line.

** Searching files by age

- Search for files in your home directory which have been modified in
  the last twenty-four hours.

#+begin_example
  $ find $HOME -mtime 0
#+end_example

This command works this way because the time since each file was last
modified is divided by 24 hours and any remainder is discarded. That
means that to match *-mtime* *0*, a file will have to have a
modification in the past which is less than 24 hours ago.

** Searching files by permissions

- Search for files which are executable but not readable.

#+begin_example
  $ find /sbin /usr/sbin -executable \! -readable -print
#+end_example

- Search for files which have read and write permission for their owner,
  and group, but which other users can read but not write to.

#+begin_example
  $ find . -perm 664
#+end_example

Files which meet these criteria but have other permissions bits set (for
example if someone can execute the file) will not be matched.

- Search for files which have read and write permission for their owner
  and group, and which other users can read, without regard to the
  presence of any extra permission bits (for example the executable
  bit).

#+begin_example
  $ find . -perm -664
#+end_example

This will match a file which has mode /0777/, for example.

- Search for files which are writable by somebody (their owner, or their
  group, or anybody else).

#+begin_example
  $ find . -perm /222
#+end_example

- Search for files which are writable by either their owner or their
  group.

#+begin_example
  $ find . -perm /220
  $ find . -perm /u+w,g+w
  $ find . -perm /u=w,g=w
#+end_example

All three of these commands do the same thing, but the first one uses
the octal representation of the file mode, and the other two use the
symbolic form. The files don't have to be writable by both the owner and
group to be matched; either will do.

- Search for files which are writable by both their owner and their
  group.

#+begin_example
  $ find . -perm -220
  $ find . -perm -g+w,u+w
#+end_example

Both these commands do the same thing.

- A more elaborate search on permissions.

#+begin_example
  $ find . -perm -444 -perm /222 \! -perm /111
  $ find . -perm -a+r -perm /a+w \! -perm /a+x
#+end_example

These two commands both search for files that are readable for everybody
(*-perm -444* or *-perm -a+r*), have at least one write bit set (*-perm
/222* or *-perm /a+w*) but are not executable for anybody (*! -perm
/111* or *! -perm /a+x* respectively).

** Pruning - omitting files and subdirectories

- Copy the contents of //source-dir/ to //dest-dir/, but omit files and
  directories named /.snapshot/ (and anything in them). It also omits
  files or directories whose name ends in /'~'/, but not their contents.

#+begin_example
  $ cd /source-dir
  $ find . -name .snapshot -prune -o \( \! -name '*~' -print0 \) \


  | cpio -pmd0 /dest-dir
#+end_example

The construct *-prune -o \( ... -print0 \)* is quite common. The idea
here is that the expression before *-prune* matches things which are to
be pruned. However, the *-prune* action itself returns true, so the
following *-o* ensures that the right hand side is evaluated only for
those directories which didn't get pruned (the contents of the pruned
directories are not even visited, so their contents are irrelevant). The
expression on the right hand side of the *-o* is in parentheses only for
clarity. It emphasises that the *-print0* action takes place only for
things that didn't have *-prune* applied to them. Because the default
`and' condition between tests binds more tightly than *-o*, this is the
default anyway, but the parentheses help to show what is going on.

- Given the following directory of projects and their associated SCM
  administrative directories, perform an efficient search for the
  projects' roots:

#+begin_example
  $ find repo/ \
  \( -exec test -d '{}/.svn' \; \
  -or -exec test -d '{}/.git' \; \
  -or -exec test -d '{}/CVS' \; \
  \) -print -prune
#+end_example

Sample output:

#+begin_example
  repo/project1/CVS
  repo/gnu/project2/.svn
  repo/gnu/project3/.svn
  repo/gnu/project3/src/.svn
  repo/project4/.git
#+end_example

In this example, *-prune* prevents unnecessary descent into directories
that have already been discovered (for example we do not search
/project3/src/ because we already found /project3/.svn/), but ensures
sibling directories (/project2/ and /project3/) are found.

** Other useful examples

- Search for several file types.

#+begin_example
  $ find /tmp -type f,d,l
#+end_example

Search for files, directories, and symbolic links in the directory
//tmp/ passing these types as a comma-separated list (GNU extension),
which is otherwise equivalent to the longer, yet more portable:

#+begin_example
  $ find /tmp \( -type f -o -type d -o -type l \)
#+end_example

- Search for files with the particular name /needle/ and stop
  immediately when we find the first one.

#+begin_example
  $ find / -name needle -print -quit
#+end_example

- Demonstrate the interpretation of the *%f* and *%h* format directives
  of the *-printf* action for some corner-cases. Here is an example
  including some output.

#+begin_example
  $ find . .. / /tmp /tmp/TRACE compile compile/64/tests/find -maxdepth 0 -printf '[%h][%f]\n'
  [.][.]
  [.][..]
  [][/]
  [][tmp]
  [/tmp][TRACE]
  [.][compile]
  [compile/64/tests][find]
#+end_example

* EXIT STATUS
*find* exits with status 0 if all files are processed successfully,
greater than 0 if errors occur. This is deliberately a very broad
description, but if the return value is non-zero, you should not rely on
the correctness of the results of *find*.

When some error occurs, *find* may stop immediately, without completing
all the actions specified. For example, some starting points may not
have been examined or some pending program invocations for *-exec ... {}
+* or *"-execdir ... {} +* may not have been performed.

* HISTORY
As of findutils-4.2.2, shell metacharacters (`*', `?' or `[]' for
example) used in filename patterns match a leading `.', because IEEE
POSIX interpretation 126 requires this.

As of findutils-4.3.3, *-perm /000* now matches all files instead of
none.

Nanosecond-resolution timestamps were implemented in findutils-4.3.3.

As of findutils-4.3.11, the *-delete* action sets *find*'s exit status
to a nonzero value when it fails. However, *find* will not exit
immediately. Previously, *find*'s exit status was unaffected by the
failure of *-delete*.

| Feature              | Added in | Also occurs in |
| -newerXY             | 4.3.3    | BSD            |
| -D                   | 4.3.1    |                |
| -O                   | 4.3.1    |                |
| -readable            | 4.3.0    |                |
| -writable            | 4.3.0    |                |
| -executable          | 4.3.0    |                |
| -regextype           | 4.2.24   |                |
| -exec ... +          | 4.2.12   | POSIX          |
| -execdir             | 4.2.12   | BSD            |
| -okdir               | 4.2.12   |                |
| -samefile            | 4.2.11   |                |
| -H                   | 4.2.5    | POSIX          |
| -L                   | 4.2.5    | POSIX          |
| -P                   | 4.2.5    | BSD            |
| -delete              | 4.2.3    |                |
| -quit                | 4.2.3    |                |
| -d                   | 4.2.3    | BSD            |
| -wholename           | 4.2.0    |                |
| -iwholename          | 4.2.0    |                |
| -ignore_readdir_race | 4.2.0    |                |
| -fls                 | 4.0      |                |
| -ilname              | 3.8      |                |
| -iname               | 3.8      |                |
| -ipath               | 3.8      |                |
| -iregex              | 3.8      |                |

The syntax .B -perm +MODE was removed in findutils-4.5.12, in favour of
.B -perm */MODE*. The *+MODE* syntax had been deprecated since
findutils-4.2.21 which was released in 2005.

* NON-BUGS
** Operator precedence surprises
The command *find . -name afile -o -name bfile -print* will never print
/afile/ because this is actually equivalent to *find . -name afile -o \(
-name bfile -a -print \)*. Remember that the precedence of *-a* is
higher than that of *-o* and when there is no operator specified between
tests, *-a* is assumed.

** “paths must precede expression” error message
#+begin_example
  $ find . -name *.c -print
  find: paths must precede expression
  find: possible unquoted pattern after predicate `-name'?
#+end_example

This happens when the shell could expand the pattern /*.c/ to more than
one file name existing in the current directory, and passing the
resulting file names in the command line to *find* like this:

#+begin_example
  find . -name frcode.c locate.c word_io.c -print
#+end_example

That command is of course not going to work, because the *-name*
predicate allows exactly only one pattern as argument. Instead of doing
things this way, you should enclose the pattern in quotes or escape the
wildcard, thus allowing *find* to use the pattern with the wildcard
during the search for file name matching instead of file names expanded
by the parent shell:

#+begin_example
  $ find . -name '*.c' -print
  $ find . -name \*.c -print
#+end_example

* BUGS
There are security problems inherent in the behaviour that the POSIX
standard specifies for *find*, which therefore cannot be fixed. For
example, the *-exec* action is inherently insecure, and *-execdir*
should be used instead.

The environment variable *LC_COLLATE* has no effect on the *-ok* action.

* REPORTING BUGS
GNU findutils online help:
<https://www.gnu.org/software/findutils/#get-help>\\
Report any translation bugs to <https://translationproject.org/team/>

Report any other issue via the form at the GNU Savannah bug tracker:

#+begin_quote
  <https://savannah.gnu.org/bugs/?group=findutils>
#+end_quote

General topics about the GNU findutils package are discussed at the
/bug-findutils/ mailing list:

#+begin_quote
  <https://lists.gnu.org/mailman/listinfo/bug-findutils>
#+end_quote

* COPYRIGHT
Copyright © 1990-2021 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.\\
This is free software: you are free to change and redistribute it. There
is NO WARRANTY, to the extent permitted by law.

* SEE ALSO
*chmod*(1), *locate*(1), *ls*(1), *updatedb*(1), *xargs*(1), *lstat*(2),
*stat*(2), *ctime*(3) *fnmatch*(3), *printf*(3), *strftime*(3),
*locatedb*(5), *regex*(7)

Full documentation <https://www.gnu.org/software/findutils/find>\\
or available locally via: *info find*

 #+INCLUDE: "./footer.org"