.\"	$OpenBSD: find.1,v 1.9 1996/09/01 07:26:45 tholo Exp $
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.\"	from: @(#)find.1	8.1 (Berkeley) 6/6/93
.\"
.Dd August 31, 1996
.Dt FIND 1
.Os
.Sh NAME
.Nm find
.Nd walk a file hierarchy
.Sh SYNOPSIS
.Nm find
.Op Fl HdhXx
.Op Fl f Ar file
.Op Ar file ...
.Ar expression
.Sh DESCRIPTION
.Nm Find
recursively descends the directory tree for each
.Ar file
listed, evaluating an
.Ar expression
(composed of the ``primaries'' and ``operands'' listed below) in terms
of each file in the tree.
.Pp
The options are as follows:
.Pp
.Bl -tag -width Ds
.It Fl H
The
.Fl H
option causes the file information and file type (see
.Xr stat  2  ) ,
returned for each symbolic link encountered on the command line to be 
those of the file referenced by the link, not the link itself.
If the referenced file does not exist, the file information and type will
be for the link itself.  File information of all symbolic links not on 
the command line is that of the link itself.
.It Fl d
The
.Fl d
option causes
.Nm find
to perform a depth\-first traversal, i.e. directories
are visited in post\-order and all entries in a directory will be acted
on before the directory itself.
By default,
.Nm find
visits directories in pre\-order, i.e. before their contents.
Note, the default is
.Ar not
a breadth\-first traversal.
.It Fl f
The
.Fl f
option specifies a file hierarchy for
.Nm find
to traverse.
File hierarchies may also be specified as the operands immediately
following the options.
.It Fl h
The
.Fl h
option causes the file information and file type (see
.Xr stat  2  ) ,
returned for each symbolic link to be those of the file referenced by the
link, not the link itself.
If the referenced file does not exist, the file information and type will
be for the link itself.
.It Fl X
The
.Fl X
option is a modification to permit
.Nm
to be safely used in conjunction with
.Xr xargs 1 .
If a file name contains any of the delimiting characters used by
.Xr xargs ,
a diagnostic message is displayed on standard error, and the file
is skipped.
The delimiting characters include single (`` ' '') and double (`` " '')
quotes, backslash (``\e''), space, tab and newline characters.
As an alternative, the
.Fl print0
function may be used safely in conjunction with the
.Fl 0
argument to
.Xr xargs 1
.It Fl x
The
.Fl x
option prevents
.Nm find
from descending into directories that have a device number different
than that of the file from which the descent began.
.El
.Sh PRIMARIES
.Bl -tag -width Ds
.It Ic -atime Ar n 
True if the difference between the file last access time and the time
.Nm find
was started, rounded up to the next full 24\-hour period, is
.Ar n
24\-hour periods.
.It Ic -ctime Ar n 
True if the difference between the time of last change of file status
information and the time
.Nm find
was started, rounded up to the next full 24\-hour period, is
.Ar n
24\-hour periods.
.It Ic -empty
True if the current file or directory is empty.
.It Ic -exec Ar utility Op argument ... ; 
True if the program named
.Ar utility
returns a zero value as its exit status.
Optional arguments may be passed to the utility.
The expression must be terminated by a semicolon (``;'').
If the string ``{}'' appears anywhere in the utility name or the
arguments it is replaced by the pathname of the current file.
.Ar Utility
will be executed from the directory from which
.Nm find
was executed.
.It Ic -follow
Follow symbolic links.
.It Ic -fstype Ar type 
True if the file is contained in a file system of type
.Ar type .
Two special file system types are recognized: ``local'' and ``rdonly''.
These do not describe actual file system types;
the former matches any file system physically mounted on the system where
the
.Nm find
is being executed, and the latter matches any file system which is
mounted read-only.
.It Ic -group Ar gname 
True if the file belongs to the group
.Ar gname  .
If
.Ar gname
is numeric and there is no such group name, then
.Ar gname
is treated as a group id.
.It Ic -inum Ar n 
True if the file has inode number
.Ar n  .
.It Ic -links Ar n 
True if the file has
.Ar n
links.
.It Ic -ls
This primary always evaluates to true.
The following information for the current file is written to standard output:
its inode number, size in 512\-byte blocks, file permissions, number of hard
links, owner, group, size in bytes, last modification time, and pathname.
If the file is a block or character special file, the major and minor numbers
will be displayed instead of the size in bytes.
If the file is a symbolic link, the pathname of the linked\-to file will be
displayed preceded by ``\->''.
The format is identical to that produced by ``ls \-dgils''.
.It Ic -maxdepth Ar n
True if the current search depth is less than or equal to what is specified in
.Ar n .
.It Ic -mindepth Ar n
True if the current search depth is at least what is specified in
.Ar n .
.It Ic -mtime Ar n 
True if the difference between the file last modification time and the time
.Nm find
was started, rounded up to the next full 24\-hour period, is
.Ar n
24\-hour periods.
.It Ic \&-ok Ar utility Ns Op argument ... ; 
The
.Ic \&-ok
primary is identical to the
.Ic -exec
primary with the exception that
.Nm find
requests user affirmation for the execution of the utility by printing
a message to the terminal and reading a response.
If the response is other than ``y'' the command is not executed and the
value of the
.Ar \&ok
expression is false.
.It Ic -name Ar pattern 
True if the last component of the pathname being examined matches
.Ar pattern  .
Special shell pattern matching characters (``['', ``]'', ``*'', and ``?'')
may be used as part of
.Ar pattern  .
These characters may be matched explicitly by escaping them with a
backslash (``\e'').
.It Ic -newer Ar file 
True if the current file has a more recent last modification time than
.Ar file  .
.It Ic -nouser
True if the file belongs to an unknown user.
.It Ic -nogroup
True if the file belongs to an unknown group.
.It Ic -path Ar pattern 
True if the pathname being examined matches
.Ar pattern  .
Special shell pattern matching characters (``['', ``]'', ``*'', and ``?'')
may be used as part of
.Ar pattern  .
These characters may be matched explicitly by escaping them with a
backslash (``\e'').
Slashes (``/'') are treated as normal characters and do not have to be
matched explicitly.
.It Ic -perm Op Fl Ns Ar mode 
The
.Ar mode
may be either symbolic (see
.Xr chmod  1  )
or an octal number.
If the mode is symbolic, a starting value of zero is assumed and the
mode sets or clears permissions without regard to the process' file mode
creation mask.
If the mode is octal, only bits 07777
.Pf ( Dv S_ISUID
|
.Dv S_ISGID
|
.Dv S_ISTXT
|
.Dv S_IRWXU
|
.Dv S_IRWXG
|
.Dv S_IRWXO )
of the file's mode bits participate
in the comparison.
If the mode is preceded by a dash (``\-''), this primary evaluates to true
if at least all of the bits in the mode are set in the file's mode bits.
If the mode is not preceded by a dash, this primary evaluates to true if
the bits in the mode exactly match the file's mode bits.
Note, the first character of a symbolic mode may not be a dash (``\-'').
.It Ic -print
This primary always evaluates to true.
It prints the pathname of the current file to standard output, followed
by a newline character.
If neither
.Ic -exec ,
.Ic -ls ,
.Ic -ok ,
nor
.Ic -print0
is specified, the given expression shall be effectively replaced by
.Cm \&( Ns Ar given\& expression Ns Cm \&) 
.Ic -print .
.It Ic -print0
This primary always evaluates to true.
It prints the pathname of the current file to standard output, followed
by a null character.
.It Ic -prune
This primary always evaluates to true.
It causes
.Nm find
to not descend into the current file.
Note, the
.Ic -prune
primary has no effect if the
.Fl d
option was specified.
.It Ic -size Ar n Ns Op Cm c 
True if the file's size, rounded up, in 512\-byte blocks is
.Ar n  .
If
.Ar n
is followed by a ``c'', then the primary is true if the
file's size is
.Ar n
bytes.
.It Ic -type Ar t 
True if the file is of the specified type.
Possible file types are as follows:
.Pp
.Bl -tag -width flag -offset indent -compact
.It Cm W
whiteout
.It Cm b
block special
.It Cm c
character special
.It Cm d
directory
.It Cm f
regular file
.It Cm l
symbolic link
.It Cm p
FIFO
.It Cm s
socket
.El
.Pp
.It Ic -user Ar uname 
True if the file belongs to the user
.Ar uname  .
If
.Ar uname
is numeric and there is no such user name, then
.Ar uname
is treated as a user id.
.El
.Pp
All primaries which take a numeric argument allow the number to be
preceded by a plus sign (``+'') or a minus sign (``\-'').
A preceding plus sign means ``more than n'', a preceding minus sign means
``less than n'' and neither means ``exactly n'' .
.Sh OPERATORS
The primaries may be combined using the following operators.
The operators are listed in order of decreasing precedence.
.Bl -tag -width (expression) 
.It Cm \&( Ns Ar expression Ns Cm \&) 
This evaluates to true if the parenthesized expression evaluates to
true.
.Pp
.It Cm \&! Ns Ar expression 
This is the unary
.Tn NOT
operator.
It evaluates to true if the expression is false.
.Pp
.It Ar expression Cm -and Ar expression 
.It Ar expression expression 
The
.Cm -and
operator is the logical
.Tn AND
operator.
As it is implied by the juxtaposition of two expressions it does not
have to be specified.
The expression evaluates to true if both expressions are true.
The second expression is not evaluated if the first expression is false.
.Pp
.It Ar expression Cm -or Ar expression 
The
.Cm -or
operator is the logical
.Tn OR
operator.
The expression evaluates to true if either the first or the second expression
is true.
The second expression is not evaluated if the first expression is true.
.El
.Pp
All operands and primaries must be separate arguments to
.Nm find  .
Primaries which themselves take arguments expect each argument
to be a separate argument to
.Nm find  .
.Sh EXAMPLES
.Pp
The following examples are shown as given to the shell:
.Bl -tag -width findx
.It Li "find  /  \e!  -name  \*q*.c\*q  -print"
Print out a list of all the files whose names do not end in ``.c''.
.It Li "find  /  -newer  ttt  -user  wnj  -print"
Print out a list of all the files owned by user ``wnj'' that are newer
than the file ``ttt''.
.It Li "find  /  \e!  \e(  -newer  ttt  -user  wnj  \e)  -print"
Print out a list of all the files which are not both newer than ``ttt''
and owned by ``wnj''.
.It Li "find  /  \e(  -newer  ttt  -or  -user wnj  \e)  -print"
Print out a list of all the files that are either owned by ``wnj'' or
that are newer than ``ttt''.
.El
.Sh SEE ALSO
.Xr chmod 1 ,
.Xr locate 1 ,
.Xr stat 2 ,
.Xr fts 3 ,
.Xr getpwent 3 ,
.Xr getgrent 3 ,
.Xr strmode 3 ,
.Xr symlink 7
.Sh STANDARDS
The
.Nm find
utility syntax is a superset of the syntax specified by the
.St -p1003.2
standard.
.Pp
The options and the
.Ic -empty ,
.Ic -follow ,
.Ic -fstype ,
.Ic -inum ,
.Ic -links ,
.Ic -ls ,
.Ic -maxdepth ,
.Ic -mindepth
and
.Ic -print0
primaries are extensions to
.St -p1003.2 .
.Pp
Historically, the
.Fl d ,
.Fl s
and
.Fl x
options were implemented using the primaries ``\-depth'', ``\-follow'',
and ``\-xdev''.
These primaries always evaluated to true.
As they were really global variables that took effect before the traversal
began, some legal expressions could have unexpected results.
An example is the expression ``\-print \-o \-depth''.
As \-print always evaluates to true, the standard order of evaluation
implies that \-depth would never be evaluated.
This is not the case.
.Pp
The operator ``-or'' was implemented as ``\-o'', and the operator ``-and''
was implemented as ``\-a''.
.Pp
Historic implementations of the
.Ic -exec
and
.Ic -ok
primaries did not replace the string ``{}'' in the utility name or the
utility arguments if it had preceding or following non-whitespace characters.
This version replaces it no matter where in the utility name or arguments
it appears.
.Sh BUGS
The special characters used by
.Nm find
are also special characters to many shell programs.
In particular, the characters ``*'', ``['', ``]'', ``?'', ``('', ``)'',
``!'', ``\e'' and ``;'' may have to be escaped from the shell.
.Pp
As there is no delimiter separating options and file names or file
names and the
.Ar expression ,
it is difficult to specify files named ``-xdev'' or ``!''.
These problems are handled by the
.Fl f
option and the
.Xr getopt 3
``--'' construct.