telnetd: filter potentially dangerous env vars passed from telnet client

[dragonfly.git] / usr.bin / find / find.1

.\" Copyright (c) 1990, 1993
.\"     The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"     This product includes software developed by the University of
.\"     California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)find.1      8.7 (Berkeley) 5/9/95
.\" $FreeBSD: src/usr.bin/find/find.1,v 1.71 2005/01/11 10:32:51 ru Exp $
.\" $DragonFly: src/usr.bin/find/find.1,v 1.4 2007/04/20 08:04:20 swildner Exp $
.\"
.Dd May 3, 2001
.Dt FIND 1
.Os
.Sh NAME
.Nm find
.Nd walk a file hierarchy
.Sh SYNOPSIS
.Nm
.Op Fl H | Fl L | Fl P
.Op Fl EXdsx
.Op Fl f Ar pathname
.Op Ar pathname ...
.Ar expression
.Sh DESCRIPTION
The
.Nm
utility recursively descends the directory tree for each
.Ar pathname
listed, evaluating an
.Ar expression
(composed of the
.Dq primaries
and
.Dq operands
listed below) in terms
of each file in the tree.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl E
Interpret regular expressions followed by
.Ic -regex
and
.Ic -iregex
options as extended (modern) regular expressions rather than basic
regular expressions (BRE's).
The
.Xr re_format 7
manual page fully describes both formats.
.It Fl H
Cause the file information and file type (see
.Xr stat 2 )
returned for each symbolic link specified 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 L
Cause 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.
.Pp
This option is equivalent to the deprecated
.Ic -follow
primary.
.It Fl P
Cause the file information and file type (see
.Xr stat 2 )
returned for each symbolic link to be those of the link itself.
This is the default.
.It Fl X
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 1 ,
a diagnostic message is displayed on standard error, and the file
is skipped.
The delimiting characters include single
.Pq Dq Li " ' "
and double
.Pq Dq Li " \*q "
quotes, backslash
.Pq Dq Li \e ,
space, tab and newline characters.
.Pp
However, you may wish to consider the
.Fl print0
primary in conjunction with
.Dq Nm xargs Fl 0
as an effective alternative.
.It Fl d
Cause
.Nm
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
visits directories in pre-order, i.e., before their contents.
Note, the default is
.Em not
a breadth-first traversal.
.Pp
This option is equivalent to the
.Ic -depth
primary of
.St -p1003.1-2001 .
.Fl d
can be useful when
.Nm
is used with
.Xr cpio 1
to process files that are contained in directories with unusual permissions.
It ensures that you have write permission while you are placing files in a
directory, then sets the directory's permissions as the last thing.
.It Fl f
Specify a file hierarchy for
.Nm
to traverse.
File hierarchies may also be specified as the operands immediately
following the options.
.It Fl s
Cause
.Nm
to traverse the file hierarchies in lexicographical order,
i.e., alphabetical order within each directory.
Note:
.Ql find -s
and
.Ql "find | sort"
may give different results.
.It Fl x
Prevent
.Nm
from descending into directories that have a device number different
than that of the file from which the descent began.
.Pp
This option is equivalent to the deprecated
.Ic -xdev
primary.
.El
.Sh PRIMARIES
.Bl -tag -width indent
.It Ic -amin Ar n
True if the difference between the file last access time and the time
.Nm
was started, rounded up to the next full minute, is
.Ar n
minutes.
.It Ic -anewer Ar file
Same as
.Ic -neweram .
.It Ic -atime Ar n Ns Op Cm smhdw
If no units are specified, this primary evaluates to
true if the difference between the file last access time and the time
.Nm
was started, rounded up to the next full 24-hour period, is
.Ar n
24-hour periods.
.Pp
If units are specified, this primary evaluates to
true if the difference between the file last access time and the time
.Nm
was started is exactly
.Ar n
units.
Possible time units are as follows:
.Pp
.Bl -tag -width indent -compact
.It Cm s
second
.It Cm m
minute (60 seconds)
.It Cm h
hour (60 minutes)
.It Cm d
day (24 hours)
.It Cm w
week (7 days)
.El
.Pp
Any number of units may be combined in one
.Ic -atime
argument, for example,
.Dq Li "-atime -1h30m" .
Units are probably only useful when used in conjunction with the
.Cm +
or
.Cm -
modifier.
.It Ic -cmin Ar n
True if the difference between the time of last change of file status
information and the time
.Nm
was started, rounded up to the next full minute, is
.Ar n
minutes.
.It Ic -cnewer Ar file
Same as
.Ic -newercm .
.It Ic -ctime Ar n Ns Op Cm smhdw
If no units are specified, this primary evaluates to
true if the difference between the time of last change of file status
information and the time
.Nm
was started, rounded up to the next full 24-hour period, is
.Ar n
24-hour periods.
.Pp
If units are specified, this primary evaluates to
true if the difference between the time of last change of file status
information and the time
.Nm
was started is exactly
.Ar n
units.
Please refer to the
.Ic -atime
primary description for information on supported time units.
.It Ic -delete
Delete found files and/or directories.
Always returns true.
This executes
from the current working directory as
.Nm
recurses down the tree.
It will not attempt to delete a filename with a
.Dq Pa /
character in its pathname relative to
.Dq Pa \&.
for security reasons.
Depth-first traversal processing is implied by this option.
.It Ic -depth
Always true;
same as the
.Fl d
option.
.It Ic -depth Ar n
True if the depth of the file relative to the starting point of the traversal
is
.Ar n .
.It Ic -empty
True if the current file or directory is empty.
.It Ic -exec Ar utility Oo Ar argument ... Oc Li \&;
True if the program named
.Ar utility
returns a zero value as its exit status.
Optional
.Ar arguments
may be passed to the utility.
The expression must be terminated by a semicolon
.Pq Dq Li \&; .
If you invoke
.Nm
from a shell you may need to quote the semicolon if the shell would
otherwise treat it as a control operator.
If the string
.Dq Li {}
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
was executed.
.Ar Utility
and
.Ar arguments
are not subject to the further expansion of shell patterns
and constructs.
.It Ic -exec Ar utility Oo Ar argument ... Oc Li {} +
Same as
.Ic -exec ,
except that
.Dq Li {}
is replaced with as many pathnames as possible for each invocation of
.Ar utility .
This behaviour is similar to that of
.Xr xargs 1 .
.It Ic -execdir Ar utility Oo Ar argument ... Oc Li \&;
The
.Ic -execdir
primary is identical to the
.Ic -exec
primary with the exception that
.Ar utility
will be executed from the directory that holds
the current file.
The filename substituted for
the string
.Dq Li {}
is not qualified.
.It Ic -flags Oo Cm - Ns | Ns Cm + Oc Ns Ar flags , Ns Ar notflags
The flags are specified using symbolic names (see
.Xr chflags 1 ) .
Those with the
.Qq Li no
prefix (except
.Qq Li nodump )
are said to be
.Ar notflags .
Flags in
.Ar flags
are checked to be set, and flags in
.Ar notflags
are checked to be not set.
Note that this is different from
.Ic -perm ,
which only allows the user to specify mode bits that are set.
.Pp
If flags are preceded by a dash
.Pq Dq Li - ,
this primary evaluates to true
if at least all of the bits in
.Ar flags
and none of the bits in
.Ar notflags
are set in the file's flags bits.
If flags are preceded by a plus
.Pq Dq Li + ,
this primary evaluates to true
if any of the bits in
.Ar flags
is set in the file's flags bits,
or any of the bits in
.Ar notflags
is not set in the file's flags bits.
Otherwise,
this primary evaluates to true
if the bits in
.Ar flags
exactly match the file's flags bits,
and none of the
.Ar flags
bits match those of
.Ar notflags .
.It Ic -fstype Ar type
True if the file is contained in a file system of type
.Ar type .
The
.Xr sysctl 8
command can be used to find out the types of file systems
that are available on the system:
.Pp
.Dl "sysctl vfs"
.Pp
In addition, there are two pseudo-types,
.Dq Li local
and
.Dq Li rdonly .
The former matches any file system physically mounted on the system where
the
.Nm
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 -iname Ar pattern
Like
.Ic -name ,
but the match is case insensitive.
.It Ic -inum Ar n
True if the file has inode number
.Ar n .
.It Ic -ipath Ar pattern
Like
.Ic -path ,
but the match is case insensitive.
.It Ic -iregex Ar pattern
Like
.Ic -regex ,
but the match is case insensitive.
.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
.Dq Li -> .
The format is identical to that produced by
.Bk -words
.Nm ls Fl dgils .
.Ek
.It Ic -maxdepth Ar n
Always true; descend at most
.Ar n
directory levels below the command line arguments.
If any
.Ic -maxdepth
primary is specified, it applies to the entire expression even if it would
not normally be evaluated.
.Ic -maxdepth Li 0
limits the whole search to the command line arguments.
.It Ic -mindepth Ar n
Always true; do not apply any tests or actions at levels less than
.Ar n .
If any
.Ic -mindepth
primary is specified, it applies to the entire expression even if it would
not normally be evaluated.
.Ic -mindepth Li 1
processes all but the command line arguments.
.It Ic -mmin Ar n
True if the difference between the file last modification time and the time
.Nm
was started, rounded up to the next full minute, is
.Ar n
minutes.
.It Ic -mnewer Ar file
Same as
.Ic -newer .
.It Ic -mtime Ar n Ns Op Cm smhdw
If no units are specified, this primary evaluates to
true if the difference between the file last modification time and the time
.Nm
was started, rounded up to the next full 24-hour period, is
.Ar n
24-hour periods.
.Pp
If units are specified, this primary evaluates to
true if the difference between the file last modification time and the time
.Nm
was started is exactly
.Ar n
units.
Please refer to the
.Ic -atime
primary description for information on supported time units.
.It Ic -name Ar pattern
True if the last component of the pathname being examined matches
.Ar pattern .
Special shell pattern matching characters
.Dq ( Li \&[ ,
.Dq Li \&] ,
.Dq Li * ,
and
.Dq Li \&? )
may be used as part of
.Ar pattern .
These characters may be matched explicitly by escaping them with a
backslash
.Pq Dq Li \e .
.It Ic -newer Ar file
True if the current file has a more recent last modification time than
.Ar file .
.It Ic -newer Ns Ar X Ns Ar Y Ar file
True if the current file has a more recent last access time
.Ar ( X Ns = Ns Cm a ) ,
change time
.Ar ( X Ns = Ns Cm c ) ,
or modification time
.Ar ( X Ns = Ns Cm m )
than the last access time
.Ar ( Y Ns = Ns Cm a ) ,
change time
.Ar ( Y Ns = Ns Cm c ) ,
or modification time
.Ar ( Y Ns = Ns Cm m )
of
.Ar file .
In addition, if
.Ar Y Ns = Ns Cm t ,
then
.Ar file
is instead interpreted as a direct date specification of the form
understood by
.Xr cvs 1 .
Note that
.Ic -newermm
is equivalent to
.Ic -newer .
.It Ic -nogroup
True if the file belongs to an unknown group.
.It Ic -nouser
True if the file belongs to an unknown user.
.It Ic -ok Ar utility Oo Ar argument ... Oc Li \&;
The
.Ic -ok
primary is identical to the
.Ic -exec
primary with the exception that
.Nm
requests user affirmation for the execution of the
.Ar utility
by printing
a message to the terminal and reading a response.
If the response is other than
.Dq Li y
the command is not executed and the
value of the
.Ic -ok
expression is false.
.It Ic -okdir Ar utility Oo Ar argument ... Oc Li \&;
The
.Ic -okdir
primary is identical to the
.Ic -execdir
primary with the same exception as described for the
.Ic -ok
primary.
.It Ic -path Ar pattern
True if the pathname being examined matches
.Ar pattern .
Special shell pattern matching characters
.Dq ( Li \&[ ,
.Dq Li \&] ,
.Dq Li * ,
and
.Dq Li \&? )
may be used as part of
.Ar pattern .
These characters may be matched explicitly by escaping them with a
backslash
.Pq Dq Li \e .
Slashes
.Pq Dq Li /
are treated as normal characters and do not have to be
matched explicitly.
.It Ic -perm Oo Cm - Ns | Ns Cm + Oc Ns Ar mode
The
.Ar mode
may be either symbolic (see
.Xr chmod 1 )
or an octal number.
If the
.Ar mode
is symbolic, a starting value of zero is assumed and the
.Ar mode
sets or clears permissions without regard to the process' file mode
creation mask.
If the
.Ar mode
is octal, only bits 07777
.Pq Dv S_ISUID | S_ISGID | S_ISTXT | S_IRWXU | S_IRWXG | S_IRWXO
of the file's mode bits participate
in the comparison.
If the
.Ar mode
is preceded by a dash
.Pq Dq Li - ,
this primary evaluates to true
if at least all of the bits in the
.Ar mode
are set in the file's mode bits.
If the
.Ar mode
is preceded by a plus
.Pq Dq Li + ,
this primary evaluates to true
if any of the bits in the
.Ar mode
are set in the file's mode bits.
Otherwise, this primary evaluates to true if
the bits in the
.Ar mode
exactly match the file's mode bits.
Note, the first character of a symbolic mode may not be a dash
.Pq Dq Li - .
.It Ic -print
This primary always evaluates to true.
It prints the pathname of the current file to standard output.
If none of
.Ic -exec , -ls , -print0 ,
or
.Ic -ok
is specified, the given expression shall be effectively replaced by
.Cm \&( Ar "given expression" 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 an
.Tn ASCII NUL
character (character code 0).
.It Ic -prune
This primary always evaluates to true.
It causes
.Nm
to not descend into the current file.
Note, the
.Ic -prune
primary has no effect if the
.Fl d
option was specified.
.It Ic -regex Ar pattern
True if the whole path of the file matches
.Ar pattern
using regular expression.
To match a file named
.Dq Pa ./foo/xyzzy ,
you can use the regular expression
.Dq Li ".*/[xyz]*"
or
.Dq Li ".*/foo/.*" ,
but not
.Dq Li xyzzy
or
.Dq Li /foo/ .
.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
.Cm c ,
then the primary is true if the
file's size is
.Ar n
bytes (characters).
.It Ic -type Ar t
True if the file is of the specified type.
Possible file types are as follows:
.Pp
.Bl -tag -width indent -compact
.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
.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
.Pq Dq Li +
or a minus sign
.Pq Dq Li - .
A preceding plus sign means
.Dq more than n ,
a preceding minus sign means
.Dq less than n
and neither means
.Dq exactly n .
.Sh OPERATORS
The primaries may be combined using the following operators.
The operators are listed in order of decreasing precedence.
.Pp
.Bl -tag -width "( expression )" -compact
.It Cm \&( Ar expression Cm \&)
This evaluates to true if the parenthesized expression evaluates to
true.
.Pp
.It Cm \&! Ar expression
.It Cm -false Ar expression
.It Cm -not 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 .
Primaries which themselves take arguments expect each argument
to be a separate argument to
.Nm .
.Sh EXAMPLES
The following examples are shown as given to the shell:
.Bl -tag -width indent
.It Li "find / \e! -name \*q*.c\*q"
Print out a list of all the files whose names do not end in
.Pa .c .
.It Li "find / -newer ttt -user wnj"
Print out a list of all the files owned by user
.Dq wnj
that are newer
than the file
.Pa ttt .
.It Li "find / \e! \e( -newer ttt -user wnj \e)"
Print out a list of all the files which are not both newer than
.Pa ttt
and owned by
.Dq wnj .
.It Li "find / \e( -newer ttt -or -user wnj \e)"
Print out a list of all the files that are either owned by
.Dq wnj
or that are newer than
.Pa ttt .
.It Li "find / -newerct '1 minute ago'"
Print out a list of all the files whose inode change time is more
recent than the current time minus one minute.
.It Li "find / -type f -exec echo {} \e;"
Use the
.Xr echo 1
command to print out a list of all the files.
.It Li "find /usr/src -name CVS -prune -o -depth +6"
Find files and directories that are at least seven levels deep
in the working directory
.Pa /usr/src .
.It Li "find /usr/src -name CVS -prune -o -mindepth 7"
Is not equivalent to the previous example, since
.Ic -prune
is not evaluated below level seven.
.El
.Sh COMPATIBILITY
The
.Ic -follow
primary is deprecated; the
.Fl L
option should be used instead.
See the
.Sx STANDARDS
section below for details.
.Sh SEE ALSO
.Xr chflags 1 ,
.Xr chmod 1 ,
.Xr cvs 1 ,
.Xr locate 1 ,
.Xr whereis 1 ,
.Xr which 1 ,
.Xr xargs 1 ,
.Xr stat 2 ,
.Xr fts 3 ,
.Xr getgrent 3 ,
.Xr getpwent 3 ,
.Xr strmode 3 ,
.Xr re_format 7 ,
.Xr symlink 7
.Sh STANDARDS
The
.Nm
utility syntax is a superset of the syntax specified by the
.St -p1003.1-2001
standard.
.Pp
All the single character options except
.Ic -H
and
.Ic -L
as well as the
.Ic -iname , -inum , -iregex , -print0 , -delete , -ls ,
and
.Ic -regex
primaries are extensions to
.St -p1003.1-2001 .
.Pp
Historically, the
.Fl d , L
and
.Fl x
options were implemented using the primaries
.Ic -depth , -follow ,
and
.Ic -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
.Ic -print Cm -o Ic -depth .
As
.Ic -print
always evaluates to true, the standard order of evaluation
implies that
.Ic -depth
would never be evaluated.
This is not the case.
.Pp
The operator
.Cm -or
was implemented as
.Cm -o ,
and the operator
.Cm -and
was implemented as
.Cm -a .
.Pp
Historic implementations of the
.Ic -exec
and
.Ic -ok
primaries did not replace the string
.Dq Li {}
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.
.Pp
The
.Fl E
option was inspired by the equivalent
.Xr grep 1
and
.Xr sed 1
options.
.Sh HISTORY
A
.Nm
command appeared in
.At v1 .
.Sh BUGS
The special characters used by
.Nm
are also special characters to many shell programs.
In particular, the characters
.Dq Li * ,
.Dq Li \&[ ,
.Dq Li \&] ,
.Dq Li \&? ,
.Dq Li \&( ,
.Dq Li \&) ,
.Dq Li \&! ,
.Dq Li \e
and
.Dq Li \&;
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
.Pa -xdev
or
.Pa \&! .
These problems are handled by the
.Fl f
option and the
.Xr getopt 3
.Dq Fl Fl
construct.
.Pp
The
.Ic -delete
primary does not interact well with other options that cause the file system
tree traversal options to be changed.
.Pp
The
.Ic -mindepth
and
.Ic -maxdepth
primaries are actually global options (as documented above).
They should
probably be replaced by options which look like options.