path: root/docs/bfs.1

.\" Copyright © Tavian Barnes <tavianator@tavianator.com>
.\" SPDX-License-Identifier: 0BSD
.TH BFS 1 2024-10-31 "bfs 4.0.4"
.SH NAME
bfs \- breadth-first search for your files
.SH SYNOPSIS
.B bfs
.RB [ flags ...]
.RI [ paths ...]
.RB [ expression ...]
.PP
flags
.RB ( \-H / \-L / \-P
etc.),
.IR paths ,
and
.B expressions
may be freely mixed in any order.
.SH DESCRIPTION
.B bfs
is a breadth-first version of the UNIX
.BR find (1)
command.
.PP
.B bfs
supports almost every feature from every major
.BR find (1)
implementation, so your existing command lines should work as-is.
It also adds some features of its own, such as a more forgiving command line parser and some additional options.
.PP
Each
.I path
specified on the command line is treated as a starting path to search through.
If no paths are specified, the current directory
.RI ( . )
is searched by default.
.PP
Like
.BR find (1),
.B bfs
interprets its arguments as a short-circuiting Boolean expression.
For example,
.PP
.nf
.RS
.B bfs \e( \-name '*.txt' \-or \-lname '*.txt' \e) \-and \-print
.RE
.fi
.PP
will print all the paths that are either .txt files or symbolic links to .txt files.
.B \-and
is implied between two consecutive expressions, so this is equivalent:
.PP
.nf
.RS
.B bfs \e( \-name '*.txt' \-or \-lname '*.txt' \e) \-print
.RE
.fi
.PP
Finally,
.B \-print
is implied if no actions are specified, so this too is equivalent:
.PP
.nf
.RS
.B bfs \-name '*.txt' \-or \-lname '*.txt'
.RE
.fi
.PP
Most options that take a numeric argument
.I N
will also accept
.I \-N
or
.IR +N .
.I \-N
means "less than
.IR N ,"
and
.I +N
means "greater than
.IR N ."
.SH FLAGS
.TP
.B \-H
Follow symbolic links on the command line, but not while searching.
.TP
.B \-L
Follow all symbolic links.
.TP
.B \-P
Never follow symbolic links (the default).
.TP
.B \-E
Use extended regular expressions (same as
.B \-regextype
.IR posix-extended ).
.TP
.B \-X
Filter out files with
.RB non- xargs (1)-safe
names.
.TP
.B \-d
Search in post-order (same as
.BR \-depth ).
.TP
.B \-s
Visit directory entries in sorted order.
The sorting takes place within each directory separately, which makes it different from
.B bfs ... |
.BR sort ,
but still provides a deterministic ordering.
.TP
.B \-x
Don't descend into other mount points (same as
.BR \-xdev ).
.TP
.BI "\-f " PATH
Treat
.I PATH
as a path to search (useful if it begins with a dash).
.TP
.BI "\-D " FLAG
Turn on a debugging flag (see
.B \-D
.IR help ).
.PP
.BI \-O N
.RS
Enable optimization level
.I N
(default:
.IR 3 ).
.TP
.BI \-O 0
Disable all optimizations.
.TP
.BI \-O 1
Basic logical simplifications.
.TP
.BI \-O 2
All
.BI \-O 1
optimizations, plus dead code elimination and data flow analysis.
.TP
.BI \-O 3
All
.BI \-O 2
optimizations, plus re-order expressions to reduce expected cost.
.TP
\fB\-O\fI4\fR/\fB\-O\fIfast\fR
All optimizations, including aggressive optimizations that may alter the observed behavior in corner cases.
.RE
.PP
\fB\-S \fIbfs\fR|\fIdfs\fR|\fIids\fR|\fIeds\fR
.RS
Choose the search strategy.
.TP
.I bfs
Breadth-first search (the default).
.TP
.I dfs
Depth-first search.
Uses less memory than breadth-first search, but is typically slower to return relevant results.
.TP
.I ids
Iterative deepening search.
Performs repeated depth-first searches with increasing depth limits.
This gives results in the same order as breadth-first search, but with the reduced memory consumption of depth-first search.
Tends to be very slow in practice, so use it only if you absolutely need breadth-first ordering, but
.B \-S
.I bfs
consumes too much memory.
.TP
.I eds
Exponential deepening search.
A compromise between breadth- and depth-first search, which searches exponentially increasing depth ranges (e.g. 0-1, 1-2, 2-4, 4-8, etc.).
Provides many of the benefits of breadth-first search with depth-first's reduced memory consumption.
Typically far faster than
.B \-S
.IR ids .
.RE
.TP
.BI \-j N
Search with
.I N
threads in parallel (default: number of CPUs, up to
.IR 8 ).
.SH OPERATORS
.TP
.BI "( " expression " )"
Parentheses are used for grouping expressions together.
You'll probably have to write
.B \e(
.I expression
.B \e)
to avoid the parentheses being interpreted by the shell.
.PP
\fB! \fIexpression\fR
.br
.B \-not
.I expression
.RS
The "not" operator: returns the negation of the truth value of the
.IR expression .
You may have to write \fB\e! \fIexpression\fR to avoid
.B !
being interpreted by the shell.
.RE
.PP
.I expression expression
.br
.I expression
.B \-a
.I expression
.br
.I expression
.B \-and
.I expression
.RS
Short-circuiting "and" operator: if the left-hand
.I expression
is
.BR true ,
returns the right-hand
.IR expression ;
otherwise, returns
.BR false .
.RE
.PP
.I expression
.B \-o
.I expression
.br
.I expression
.B \-or
.I expression
.RS
Short-circuiting "or" operator: if the left-hand
.I expression
is
.BR false ,
returns the right-hand
.IR expression ;
otherwise, returns
.BR true .
.RE
.TP
.IB "expression " , " expression"
The "comma" operator: evaluates the left-hand
.I expression
but discards the result, returning the right-hand
.IR expression .
.SH SPECIAL FORMS
.TP
.BI "\-exclude " expression
Exclude all paths matching the
.I expression
from the search.
This is more powerful than
.BR \-prune ,
because it applies even when the expression wouldn't otherwise be evaluated, due to
.B \-depth
or
.B \-mindepth
for example.
Exclusions are always applied before other expressions, so it may be least confusing to put them first on the command line.
.PP
.B \-help
.br
.B \-\-help
.RS
Print usage information, and exit immediately (without parsing the rest of the command line or processing any files).
.RE
.PP
.B \-version
.br
.B \-\-version
.RS
Print version information, and exit immediately.
.RE
.SH OPTIONS
.B \-color
.br
.B \-nocolor
.RS
Turn colors on or off (default:
.B \-color
if outputting to a terminal,
.B \-nocolor
otherwise).
.RE
.TP
.B \-daystart
Measure time relative to the start of today.
.TP
.B \-depth
Search in post-order (descendents first).
.TP
.B \-follow
Follow all symbolic links (same as
.BR \-L ).
.TP
.BI "\-files0\-from " FILE
Treat the NUL ('\e0')-separated paths in
.I FILE
as starting points for the search.
Pass
.B \-files0\-from
.I \-
to read the paths from standard input.
.PP
.B \-ignore_readdir_race
.br
.B \-noignore_readdir_race
.RS
Whether to report an error if
.B bfs
detects that the file tree is modified during the search (default:
.BR \-noignore_readdir_race ).
.RE
.PP
.B \-maxdepth
.I N
.br
.B \-mindepth
.I N
.RS
Ignore files deeper/shallower than
.IR N .
.RE
.TP
.B \-mount
Exclude mount points entirely from the results.
.TP
.B \-noerror
Ignore any errors that occur during traversal.
.TP
.B \-nohidden
Exclude hidden files and directories.
.TP
.B \-noleaf
Ignored; for compatibility with GNU find.
.TP
.BI "\-regextype " TYPE
Use
.IR TYPE -flavored
regular expressions.
The possible types are
.RS
.TP
.I posix-basic
POSIX basic regular expressions (the default).
.TP
.I posix-extended
POSIX extended regular expressions.
.TP
.I ed
Like
.BR ed (1)
(same as
.IR posix-basic ).
.TP
.I emacs
Like
.BR emacs (1).
.TP
.I grep
Like
.BR grep (1).
.TP
.I sed
Like
.BR sed (1)
(same as
.IR posix-basic ).
.PP
See
.BR regex (7)
for a description of regular expression syntax.
.RE
.TP
.B \-status
Display a status bar while searching.
.TP
.B \-unique
Skip any files that have already been seen.
Particularly useful along with
.BR \-L .
.PP
.B \-warn
.br
.B \-nowarn
.RS
Turn on or off warnings about the command line.
.RE
.TP
.B \-xdev
Don't descend into other mount points.
Unlike
.BR \-mount ,
the mount point itself is still included.
.SH TESTS
.TP
.B \-acl
Find files with a non-trivial Access Control List
.RB ( acl (5)).
.PP
\fB\-amin\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-Bmin\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-cmin\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-mmin\fR [\fI\-+\fR]\fIN\fR
.RS
Find files
.BR a ccessed/ B irthed/ c hanged/ m odified
.I N
minutes ago.
.RE
.PP
.B \-anewer
.I FILE
.br
.B \-Bnewer
.I FILE
.br
.B \-cnewer
.I FILE
.br
.B \-mnewer
.I FILE
.RS
Find files
.BR a ccessed/ B irthed/ c hanged/ m odified
more recently than
.I FILE
was modified.
.RE
.PP
.B \-asince
.I TIME
.br
.B \-Bsince
.I TIME
.br
.B \-csince
.I TIME
.br
.B \-msince
.I TIME
.RS
Find files
.BR a ccessed/ B irthed/ c hanged/ m odified
more recently than the ISO 8601-style timestamp
.IR TIME .
See
.BI \-newer XY
for examples of the timestamp format.
.RE
.PP
\fB\-atime\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-Btime\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-ctime\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-mtime\fR [\fI\-+\fR]\fIN\fR
.RS
Find files
.BR a ccessed/ B irthed/ c hanged/ m odified
.I N
days ago.
.RE
.TP
.B \-capable
Find files with POSIX.1e
.BR capabilities (7)
set.
.TP
.BI "\-context " GLOB
Find files whose SELinux context matches the
.IR GLOB .
.TP
\fB\-depth\fR [\fI\-+\fR]\fIN\fR
Find files with depth
.IR N .
.TP
.B \-empty
Find empty files/directories.
.PP
.B \-executable
.br
.B \-readable
.br
.B \-writable
.RS
Find files the current user can execute/read/write.
.RE
.PP
.B \-false
.br
.B \-true
.RS
Always false/true.
.RE
.TP
\fB\-flags\fR [\fI\-+\fR]\fIFLAGS\fR
Find files with matching inode
.BR FLAGS .
.TP
.BI "\-fstype " TYPE
Find files on file systems with the given
.IR TYPE .
.PP
\fB\-gid\fR [\fI\-+\fR]\fIN\fR
.br
\fB\-uid\fR [\fI\-+\fR]\fIN\fR
.RS
Find files owned by group/user ID
.IR N .
.RE
.PP
.B \-group
.I NAME
.br
.B \-user
.I NAME
.RS
Find files owned by the group/user
.IR NAME .
.RE
.TP
.B \-hidden
Find hidden files (those beginning with
.IR . ).
.PP
.B \-ilname
.I GLOB
.br
.B \-iname
.I GLOB
.br
.B \-ipath
.I GLOB
.br
.B \-iregex
.I REGEX
.br
.B \-iwholename
.I GLOB
.RS
Case-insensitive versions of
.BR \-lname / \-name / \-path / \-regex / \-wholename .
.RE
.TP
\fB\-inum\fR [\fI\-+\fR]\fIN\fR
Find files with inode number
.IR N .
.TP
\fB\-links\fR [\fI\-+\fR]\fIN\fR
Find files with
.I N
hard links.
.TP
.BI "\-lname " GLOB
Find symbolic links whose target matches the
.IR GLOB .
.TP
.BI "\-name " GLOB
Find files whose name matches the
.IR GLOB .
.TP
.BI "\-newer " FILE
Find files newer than
.IR FILE .
.TP
.BI \-newer "XY REFERENCE"
Find files whose
.I X
time is newer than the
.I Y
time of
.IR REFERENCE .
.I X
and
.I Y
can be any of
.RI [ aBcm ]
.RI ( a ccess/ B irth/ c hange/ m odification).
.I Y
may also be
.I t
to parse
.I REFERENCE
as an ISO 8601-style timestamp.  For example:
.PP
.RS
.nf
\(bu  \fI1991-12-14\fR
\(bu  \fI1991-12-14T03:00\fR
\(bu  \fI1991-12-14T03:00-07:00\fR
\(bu '\fI1991-12-14 10:00Z\fR'
.fi
.RE
.PP
.B \-nogroup
.br
.B \-nouser
.RS
Find files owned by nonexistent groups/users.
.RE
.PP
.B \-path
.I GLOB
.br
.B \-wholename
.I GLOB
.RS
Find files whose entire path matches the
.IR GLOB .
.RE
.TP
\fB\-perm\fR [\fI\-+/\fR]\fIMODE\fR
Find files with a matching mode.
.TP
.BI "\-regex " REGEX
Find files whose entire path matches the regular expression
.IR REGEX .
.TP
.BI "\-samefile " FILE
Find hard links to
.IR FILE .
.TP
.BI "\-since " TIME
Find files modified since the ISO 8601-style timestamp
.IR TIME .
See
.BI \-newer XY
for examples of the timestamp format.
.TP
\fB\-size\fR [\fI\-+\fR]\fIN\fR[\fIcwbkMGTP\fR]
Find files with the given size.
The unit can be one of
.PP
.RS
.nf
\(bu \fIc\fRhars  (1 byte)
\(bu \fIw\fRords  (2 bytes)
\(bu \fIb\fRlocks (512 bytes, the default)
\(bu \fIk\fRiB    (1024 bytes)
\(bu \fIM\fRiB    (1024 kiB)
\(bu \fIG\fRiB    (1024 MiB)
\(bu \fIT\fRiB    (1024 GiB)
\(bu \fIP\fRiB    (1024 TiB)
.fi
.RE
.TP
.B \-sparse
Find files that occupy fewer disk blocks than expected.
.TP
\fB\-type\fR [\fIbcdlpfswD\fR]
Find files of the given type.
The possible types are
.PP
.RS
\(bu
.IR b lock
device
.br
\(bu
.IR c haracter
device
.br
\(bu
.IR d irectory
.br
\(bu
.IR l ink
(symbolic)
.br
\(bu
.IR p ipe
.br
\(bu
.IR f ile
(regular)
.br
\(bu
.IR s ocket
.br
\(bu
.IR w hiteout
.br
\(bu
.IR D oor
.PP
Multiple types can be given at once, separated by commas.
For example,
.B \-type
.I d,f
matches both directories and regular files.
.RE
.TP
\fB\-used\fR [\fI\-+\fR]\fIN\fR
Find files last accessed
.I N
days after they were changed.
.TP
.B \-xattr
Find files with extended attributes
.RB ( xattr (7)).
.TP
.BI "\-xattrname " NAME
Find files with the extended attribute
.IR NAME .
.TP
\fB\-xtype\fR [\fIbcdlpfswD\fR]
Find files of the given type, following links when
.B \-type
would not, and vice versa.
.SH ACTIONS
.B \-delete
.br
.B \-rm
.RS
Delete any found files (implies
.BR \-depth ).
.RE
.TP
.BI "\-exec " "command ... {} ;"
Execute a command.
.TP
.BI "\-exec " "command ... {} +"
Execute a command with multiple files at once.
.TP
.BI "\-ok " "command ... {} ;"
Prompt the user whether to execute a command.
.PP
.B \-execdir
.I command ... {} ;
.br
.B \-execdir
.I command ... {} +
.br
.B \-okdir
.I command ... {} ;
.RS
Like
.BR \-exec / \-ok ,
but run the command in the same directory as the found file(s).
.RE
.TP
\fB\-exit\fR [\fISTATUS\fR]
Exit immediately with the given status
.RI ( 0
if unspecified).
.PP
.B \-fls
.I FILE
.br
.B \-fprint
.I FILE
.br
.B \-fprint0
.I FILE
.br
.B \-fprintf
.I FILE FORMAT
.RS
Like
.BR \-ls / \-print / \-print0 / \-printf ,
but write to
.I FILE
instead of standard output.
.RE
.TP
.BI "\-limit " N
Quit once this action is evaluated
.I N
times.
.TP
.B \-ls
List files like
.B ls
.IR \-dils .
.TP
.B \-print
Print the path to the found file.
.TP
.B \-print0
Like
.BR \-print ,
but use the null character ('\e0') as a separator rather than newlines.
Useful in conjunction with
.B xargs
.IR \-0 .
.TP
.BI "\-printf " FORMAT
Print according to a format string (see
.BR find (1)).
These additional format directives are supported:
.RS
.TP
%w
The file's birth time, in the same format as %a/%c/%t.
.TP
.RI %W k
Field
.I k
of the file's birth time, in the same format as
.RI %A k /%C k /%T k .
.RE
.TP
.B \-printx
Like
.BR \-print ,
but escape whitespace and quotation characters, to make the output safe for
.BR xargs (1).
Consider using
.B \-print0
and
.B xargs
.I \-0
instead.
.TP
.B \-prune
Don't descend into this directory.
This has no effect if
.B \-depth
is enabled (either explicitly, or implicitly by
.BR \-delete ).
Use
.B \-exclude
instead in that case.
.TP
.B \-quit
Quit immediately.
.SH ENVIRONMENT
Certain environment variables affect the behavior of
.BR bfs .
.PP
.B LANG
.br
.B LC_*
.RS
Specifies the
.BR locale (7)
in use for various things.
.B bfs
is not (yet) translated to any languages except English, but the locale will still affect the format of printed values.
Yes/no prompts (e.g. from
.BR \-ok )
will also be interpreted according to the current locale.
.RE
.PP
.B LS_COLORS
.br
.B BFS_COLORS
.RS
Controls the colors used when displaying file paths if
.B \-color
is enabled.
.B bfs
interprets
.B LS_COLORS
the same way GNU
.BR ls (1)
does (see
.BR dir_colors (5)).
.B BFS_COLORS
can be used to customize
.B bfs
without affecting other commands.
.RE
.TP
.B NO_COLOR
Causes
.B bfs
to default to
.B \-nocolor
if it is set (see https://no-color.org/).
.TP
.B PAGER
Specifies the pager used for
.B \-help
output.
Defaults to
.BR less (1),
if found on the current
.BR PATH ,
otherwise
.BR more (1).
.TP
.B PATH
Used to resolve executables for
.BR \-exec [ dir ]
and
.BR \-ok [ dir ].
.TP
.B POSIXLY_CORRECT
Makes
.B bfs
conform more strictly to the POSIX.1-2017 specification for
.BR find (1).
Currently this has two effects:
.RS
.IP \(bu
Disables warnings by default, because POSIX prohibits writing to standard error (except for the
.B \-ok
prompt), unless the command also fails with a non-zero exit status.
.IP \(bu
Makes
.B \-ls
and
.B \-fls
use 512-byte blocks instead of 1024-byte blocks.
(POSIX does not specify these actions, but BSD
.BR find (1)
implementations use 512-byte blocks, while GNU
.BR find (1)
uses 1024-byte blocks by default.)
.PP
It does not disable
.BR bfs 's
various extensions to the base POSIX functionality.
.B POSIXLY_CORRECT
has the same effects on GNU
.BR find (1).
.RE
.SH EXAMPLES
.TP
.B bfs
With no arguments,
.B bfs
prints all files under the current directory in breadth-first order.
.TP
.B bfs \-name '*.txt'
Prints all the .txt files under the current directory.
.B *.txt
is quoted to ensure the glob is processed by
.B bfs
rather than the shell.
.TP
.BI "bfs \-name access_log \-L " /var
Finds all files named
.B access_log
under
.IR /var ,
following symbolic links.
.B bfs
allows flags and paths to appear anywhere on the command line.
.TP
.BI "bfs " ~ " \-not \-user $USER"
Prints all files in your home directory not owned by you.
.TP
.B bfs \-xtype l
Finds broken symbolic links.
.TP
.B bfs \-name config \-exclude \-name .git
Finds all files named
.BR config ,
skipping every
.B .git
directory.
.TP
.B bfs \-type f \-executable \-exec strip {} +
Runs
.BR strip (1)
on all executable files it finds, passing it multiple files at a time.
.SH BUGS
https://github.com/tavianator/bfs/issues
.SH AUTHOR
Tavian Barnes <tavianator@tavianator.com>
.PP
https://tavianator.com/projects/bfs.html
.SH SEE ALSO
.BR find (1),
.BR locate (1),
.BR xargs (1)