ACK
Section: User Contributed Perl Documentation (1p)
Updated: 2014-10-24
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NAME
ack - grep-like text finder
SYNOPSIS
ack [options] PATTERN [FILE...]
ack -f [options] [DIRECTORY...]
DESCRIPTION
Ack is designed as an alternative to grep for programmers.
Ack searches the named input FILEs (or standard input if no files
are named, or the file name - is given) for lines containing a match
to the given PATTERN. By default, ack prints the matching lines.
PATTERN is a Perl regular expression. Perl regular expressions
are commonly found in other programming languages, but for the particulars
of their behavior, please consult
<http://perldoc.perl.org/perlreref.html|perlreref>. If you don't know
how to use regular expression but are interested in learning, you may
consult <http://perldoc.perl.org/perlretut.html|perlretut>. If you do not
need or want ack to use regular expressions, please see the
"-Q"/"--literal" option.
Ack can also list files that would be searched, without actually
searching them, to let you take advantage of ack's file-type filtering
capabilities.
FILE SELECTION
If files are not specified for searching, either on the command
line or piped in with the "-x" option, ack delves into
subdirectories selecting files for searching.
ack is intelligent about the files it searches. It knows about
certain file types, based on both the extension on the file and,
in some cases, the contents of the file. These selections can be
made with the --type option.
With no file selection, ack searches through regular files that
are not explicitly excluded by --ignore-dir and --ignore-file
options, either present in ackrc files or on the command line.
The default options for ack ignore certain files and directories. These
include:
- •
-
Backup files: Files matching #*# or ending with ~.
- •
-
Coredumps: Files matching core.\d+
- •
-
Version control directories like .svn and .git.
Run ack with the "--dump" option to see what settings are set.
However, ack always searches the files given on the command line,
no matter what type. If you tell ack to search in a coredump,
it will search in a coredump.
DIRECTORY SELECTION
ack descends through the directory tree of the starting directories
specified. If no directories are specified, the current working directory is
used. However, it will ignore the shadow directories used by
many version control systems, and the build directories used by the
Perl MakeMaker system. You may add or remove a directory from this
list with the --[no]ignore-dir option. The option may be repeated
to add/remove multiple directories from the ignore list.
For a complete list of directories that do not get searched, run
"ack --dump".
WHEN TO USE GREP
ack trumps grep as an everyday tool 99% of the time, but don't
throw grep away, because there are times you'll still need it.
E.g., searching through huge files looking for regexes that can be
expressed with grep syntax should be quicker with grep.
If your script or parent program uses grep "--quiet" or "--silent"
or needs exit 2 on IO error, use grep.
OPTIONS
- --ackrc
-
Specifies an ackrc file to load after all others; see ``ACKRC LOCATION SEMANTICS''.
- -A NUM, --after-context=NUM
-
Print NUM lines of trailing context after matching lines.
- -B NUM, --before-context=NUM
-
Print NUM lines of leading context before matching lines.
- --[no]break
-
Print a break between results from different files. On by default
when used interactively.
- -C [NUM], --context[=NUM]
-
Print NUM lines (default 2) of context around matching lines.
- -c, --count
-
Suppress normal output; instead print a count of matching lines for
each input file. If -l is in effect, it will only show the
number of lines for each file that has lines matching. Without
-l, some line counts may be zeroes.
If combined with -h (--no-filename) ack outputs only one total
count.
- --[no]color, --[no]colour
-
--color highlights the matching text. --nocolor suppresses
the color. This is on by default unless the output is redirected.
On Windows, this option is off by default unless the
Win32::Console::ANSI module is installed or the "ACK_PAGER_COLOR"
environment variable is used.
- --color-filename=color
-
Sets the color to be used for filenames.
- --color-match=color
-
Sets the color to be used for matches.
- --color-lineno=color
-
Sets the color to be used for line numbers.
- --[no]column
-
Show the column number of the first match. This is helpful for
editors that can place your cursor at a given position.
- --create-ackrc
-
Dumps the default ack options to standard output. This is useful for
when you want to customize the defaults.
- --dump
-
Writes the list of options loaded and where they came from to standard
output. Handy for debugging.
- --[no]env
-
--noenv disables all environment processing. No .ackrc is
read and all environment variables are ignored. By default, ack
considers .ackrc and settings in the environment.
- --flush
-
--flush flushes output immediately. This is off by default
unless ack is running interactively (when output goes to a pipe or
file).
- -f
-
Only print the files that would be searched, without actually doing
any searching. PATTERN must not be specified, or it will be taken
as a path to search.
- --files-from=FILE
-
The list of files to be searched is specified in FILE. The list of
files are separated by newlines. If FILE is "-", the list is loaded
from standard input.
- --[no]filter
-
Forces ack to act as if it were receiving input via a pipe.
- --[no]follow
-
Follow or don't follow symlinks, other than whatever starting files
or directories were specified on the command line.
This is off by default.
- -g PATTERN
-
Print files where the relative path + filename matches PATTERN.
This option can be combined with --color to make it easier to spot
the match.
- --[no]group
-
--group groups matches by file name. This is the default
when used interactively.
--nogroup prints one result per line, like grep. This is the
default when output is redirected.
- -H, --with-filename
-
Print the filename for each match. This is the default unless searching
a single explicitly specified file.
- -h, --no-filename
-
Suppress the prefixing of filenames on output when multiple files are
searched.
- --[no]heading
-
Print a filename heading above each file's results. This is the default
when used interactively.
- --help, -?
-
Print a short help statement.
- --help-types, --help=types
-
Print all known types.
- -i, --ignore-case
-
Ignore case distinctions in PATTERN
- --ignore-ack-defaults
-
Tells ack to completely ignore the default definitions provided with ack.
This is useful in combination with --create-ackrc if you really want
to customize ack.
- --[no]ignore-dir=DIRNAME, --[no]ignore-directory=DIRNAME
-
Ignore directory (as CVS, .svn, etc are ignored). May be used
multiple times to ignore multiple directories. For example, mason
users may wish to include --ignore-dir=data. The --noignore-dir
option allows users to search directories which would normally be
ignored (perhaps to research the contents of .svn/props directories).
The DIRNAME must always be a simple directory name. Nested
directories like foo/bar are NOT supported. You would need to
specify --ignore-dir=foo and then no files from any foo directory
are taken into account by ack unless given explicitly on the command
line.
- --ignore-file=FILTERTYPE:FILTERARGS
-
Ignore files matching FILTERTYPE:FILTERARGS. The filters are specified
identically to file type filters as seen in ``Defining your own types''.
- -k, --known-types
-
Limit selected files to those with types that ack knows about. This is
equivalent to the default behavior found in ack 1.
- --lines=NUM
-
Only print line NUM of each file. Multiple lines can be given with multiple
--lines options or as a comma separated list (--lines=3,5,7). --lines=4-7
also works. The lines are always output in ascending order, no matter the
order given on the command line.
- -l, --files-with-matches
-
Only print the filenames of matching files, instead of the matching text.
- -L, --files-without-matches
-
Only print the filenames of files that do NOT match.
- --match PATTERN
-
Specify the PATTERN explicitly. This is helpful if you don't want to put the
regex as your first argument, e.g. when executing multiple searches over the
same set of files.
# search for foo and bar in given files
ack file1 t/file* --match foo
ack file1 t/file* --match bar
- -m=NUM, --max-count=NUM
-
Stop reading a file after NUM matches.
- --man
-
Print this manual page.
- -n, --no-recurse
-
No descending into subdirectories.
- -o
-
Show only the part of each line matching PATTERN (turns off text
highlighting)
- --output=expr
-
Output the evaluation of expr for each line (turns off text
highlighting)
If PATTERN matches more than once then a line is output for each non-overlapping match.
For more information please see the section "Examples of --output".
- --pager=program, --nopager
-
--pager directs ack's output through program. This can also be specified
via the "ACK_PAGER" and "ACK_PAGER_COLOR" environment variables.
Using --pager does not suppress grouping and coloring like piping
output on the command-line does.
--nopager cancels any setting in ~/.ackrc, "ACK_PAGER" or "ACK_PAGER_COLOR".
No output will be sent through a pager.
- --passthru
-
Prints all lines, whether or not they match the expression. Highlighting
will still work, though, so it can be used to highlight matches while
still seeing the entire file, as in:
# Watch a log file, and highlight a certain IP address
$ tail -f ~/access.log | ack --passthru 123.45.67.89
- --print0
-
Only works in conjunction with -f, -g, -l or -c (filename output). The filenames
are output separated with a null byte instead of the usual newline. This is
helpful when dealing with filenames that contain whitespace, e.g.
# remove all files of type html
ack -f --html --print0 | xargs -0 rm -f
- -Q, --literal
-
Quote all metacharacters in PATTERN, it is treated as a literal.
- -r, -R, --recurse
-
Recurse into sub-directories. This is the default and just here for
compatibility with grep. You can also use it for turning --no-recurse off.
- -s
-
Suppress error messages about nonexistent or unreadable files. This is taken
from fgrep.
- --[no]smart-case, --no-smart-case
-
Ignore case in the search strings if PATTERN contains no uppercase
characters. This is similar to "smartcase" in vim. This option is
off by default, and ignored if "-i" is specified.
-i always overrides this option.
- --sort-files
-
Sorts the found files lexicographically. Use this if you want your file
listings to be deterministic between runs of ack.
- --show-types
-
Outputs the filetypes that ack associates with each file.
Works with -f and -g options.
- --type=[no]TYPE
-
Specify the types of files to include or exclude from a search.
TYPE is a filetype, like perl or xml. --type=perl can
also be specified as --perl, and --type=noperl can be done
as --noperl.
If a file is of both type ``foo'' and ``bar'', specifying --foo and
--nobar will exclude the file, because an exclusion takes precedence
over an inclusion.
Type specifications can be repeated and are ORed together.
See ack --help=types for a list of valid types.
- --type-add TYPE:FILTER:FILTERARGS
-
Files with the given FILTERARGS applied to the given FILTER
are recognized as being of (the existing) type TYPE.
See also ``Defining your own types''.
- --type-set TYPE:FILTER:FILTERARGS
-
Files with the given FILTERARGS applied to the given FILTER are recognized as
being of type TYPE. This replaces an existing definition for type TYPE. See
also ``Defining your own types''.
- --type-del TYPE
-
The filters associated with TYPE are removed from Ack, and are no longer considered
for searches.
- -v, --invert-match
-
Invert match: select non-matching lines
- --version
-
Display version and copyright information.
- -w, --word-regexp
-
Force PATTERN to match only whole words. The PATTERN is wrapped with
"\b" metacharacters.
- -x
-
An abbreviation for --files-from=-; the list of files to search are read
from standard input, with one line per file.
- -1
-
Stops after reporting first match of any kind. This is different
from --max-count=1 or -m1, where only one match per file is
shown. Also, -1 works with -f and -g, where -m does
not.
- --thpppt
-
Display the all-important Bill The Cat logo. Note that the exact
spelling of --thpppppt is not important. It's checked against
a regular expression.
- --bar
-
Check with the admiral for traps.
- --cathy
-
Chocolate, Chocolate, Chocolate!
THE .ackrc FILE
The .ackrc file contains command-line options that are prepended
to the command line before processing. Multiple options may live
on multiple lines. Lines beginning with a # are ignored. A .ackrc
might look like this:
# Always sort the files
--sort-files
# Always color, even if piping to a another program
--color
# Use "less -r" as my pager
--pager=less -r
Note that arguments with spaces in them do not need to be quoted,
as they are not interpreted by the shell. Basically, each line
in the .ackrc file is interpreted as one element of @ARGV.
ack looks in several locations for .ackrc files; the searching
process is detailed in ``ACKRC LOCATION SEMANTICS''. These
files are not considered if --noenv is specified on the command line.
Defining your own types
ack allows you to define your own types in addition to the predefined
types. This is done with command line options that are best put into
an .ackrc file - then you do not have to define your types over and
over again. In the following examples the options will always be shown
on one command line so that they can be easily copy & pasted.
ack --perl foo searches for foo in all perl files. ack --help=types
tells you, that perl files are files ending
in .pl, .pm, .pod or .t. So what if you would like to include .xs
files as well when searching for --perl files? ack --type-add perl:ext:xs --perl foo
does this for you. --type-add appends
additional extensions to an existing type.
If you want to define a new type, or completely redefine an existing
type, then use --type-set. ack --type-set eiffel:ext:e,eiffel defines
the type eiffel to include files with
the extensions .e or .eiffel. So to search for all eiffel files
containing the word Bertrand use ack --type-set eiffel:ext:e,eiffel --eiffel Bertrand.
As usual, you can also write --type=eiffel
instead of --eiffel. Negation also works, so --noeiffel excludes
all eiffel files from a search. Redefining also works: ack --type-set cc:ext:c,h
and .xs files no longer belong to the type cc.
When defining your own types in the .ackrc file you have to use
the following:
--type-set=eiffel:ext:e,eiffel
or writing on separate lines
--type-set
eiffel:ext:e,eiffel
The following does NOT work in the .ackrc file:
--type-set eiffel:ext:e,eiffel
In order to see all currently defined types, use --help-types, e.g.
ack --type-set backup:ext:bak --type-add perl:ext:perl --help-types
In addition to filtering based on extension (like ack 1.x allowed), ack 2
offers additional filter types. The generic syntax is
--type-set TYPE:FILTER:FILTERARGS; FILTERARGS depends on the value
of FILTER.
- is:FILENAME
-
is filters match the target filename exactly. It takes exactly one
argument, which is the name of the file to match.
Example:
--type-set make:is:Makefile
- ext:EXTENSION[,EXTENSION2[,...]]
-
ext filters match the extension of the target file against a list
of extensions. No leading dot is needed for the extensions.
Example:
--type-set perl:ext:pl,pm,t
- match:PATTERN
-
match filters match the target filename against a regular expression.
The regular expression is made case insensitive for the search.
Example:
--type-set make:match:/(gnu)?makefile/
- firstlinematch:PATTERN
-
firstlinematch matches the first line of the target file against a
regular expression. Like match, the regular expression is made
case insensitive.
Example:
--type-add perl:firstlinematch:/perl/
More filter types may be made available in the future.
ENVIRONMENT VARIABLES
For commonly-used ack options, environment variables can make life
much easier. These variables are ignored if --noenv is specified
on the command line.
- ACKRC
-
Specifies the location of the user's .ackrc file. If this file doesn't
exist, ack looks in the default location.
- ACK_OPTIONS
-
This variable specifies default options to be placed in front of
any explicit options on the command line.
- ACK_COLOR_FILENAME
-
Specifies the color of the filename when it's printed in --group
mode. By default, it's ``bold green''.
The recognized attributes are clear, reset, dark, bold, underline,
underscore, blink, reverse, concealed black, red, green, yellow,
blue, magenta, on_black, on_red, on_green, on_yellow, on_blue,
on_magenta, on_cyan, and on_white. Case is not significant.
Underline and underscore are equivalent, as are clear and reset.
The color alone sets the foreground color, and on_color sets the
background color.
This option can also be set with --color-filename.
- ACK_COLOR_MATCH
-
Specifies the color of the matching text when printed in --color
mode. By default, it's ``black on_yellow''.
This option can also be set with --color-match.
See ACK_COLOR_FILENAME for the color specifications.
- ACK_COLOR_LINENO
-
Specifies the color of the line number when printed in --color
mode. By default, it's ``bold yellow''.
This option can also be set with --color-lineno.
See ACK_COLOR_FILENAME for the color specifications.
- ACK_PAGER
-
Specifies a pager program, such as "more", "less" or "most", to which
ack will send its output.
Using "ACK_PAGER" does not suppress grouping and coloring like
piping output on the command-line does, except that on Windows
ack will assume that "ACK_PAGER" does not support color.
"ACK_PAGER_COLOR" overrides "ACK_PAGER" if both are specified.
- ACK_PAGER_COLOR
-
Specifies a pager program that understands ANSI color sequences.
Using "ACK_PAGER_COLOR" does not suppress grouping and coloring
like piping output on the command-line does.
If you are not on Windows, you never need to use "ACK_PAGER_COLOR".
AVAILABLE COLORS
ack uses the colors available in Perl's Term::ANSIColor module, which
provides the following listed values. Note that case does not matter when using
these values.
Foreground colors
black red green yellow blue magenta cyan white
bright_black bright_red bright_green bright_yellow
bright_blue bright_magenta bright_cyan bright_white
Background colors
on_black on_red on_green on_yellow
on_blue on_magenta on_cyan on_white
on_bright_black on_bright_red on_bright_green on_bright_yellow
on_bright_blue on_bright_magenta on_bright_cyan on_bright_white
ACK & OTHER TOOLS
Vim integration
ack integrates easily with the Vim text editor. Set this in your
.vimrc to use ack instead of grep:
set grepprg=ack\ -k
That example uses "-k" to search through only files of the types ack
knows about, but you may use other default flags. Now you can search
with ack and easily step through the results in Vim:
:grep Dumper perllib
Miles Sterrett has written a Vim plugin for ack which allows you to use
":Ack" instead of ":grep", as well as several other advanced features.
<https://github.com/mileszs/ack.vim>
Emacs integration
Phil Jackson put together an ack.el extension that ``provides a
simple compilation mode ... has the ability to guess what files you
want to search for based on the major-mode.''
<http://www.shellarchive.co.uk/content/emacs.html>
TextMate integration
Pedro Melo is a TextMate user who writes "I spend my day mostly
inside TextMate, and the built-in find-in-project sucks with large
projects. So I hacked a TextMate command that was using find +
grep to use ack. The result is the Search in Project with ack, and
you can find it here:
<http://www.simplicidade.org/notes/archives/2008/03/search_in_proje.html>"
Shell and Return Code
For greater compatibility with grep, ack in normal use returns
shell return or exit code of 0 only if something is found and 1 if
no match is found.
(Shell exit code 1 is "$?=256" in perl with "system" or backticks.)
The grep code 2 for errors is not used.
If "-f" or "-g" are specified, then 0 is returned if at least one
file is found. If no files are found, then 1 is returned.
DEBUGGING ACK PROBLEMS
If ack gives you output you're not expecting, start with a few simple steps.
Use --noenv
Your environment variables and .ackrc may be doing things you're
not expecting, or forgotten you specified. Use --noenv to ignore
your environment and .ackrc.
Use -f to see what files have been selected
Ack's -f was originally added as a debugging tool. If ack is
not finding matches you think it should find, run ack -f to see
what files have been selected. You can also add the "--show-types"
options to show the type of each file selected.
Use --dump
This lists the ackrc files that are loaded and the options loaded
from them.
So for example you can find a list of directories that do not get searched or where filetypes are defined.
TIPS
Use the .ackrc file.
The .ackrc is the place to put all your options you use most of
the time but don't want to remember. Put all your --type-add and
--type-set definitions in it. If you like --smart-case, set it
there, too. I also set --sort-files there.
Use -f for working with big codesets
Ack does more than search files. "ack -f --perl" will create a
list of all the Perl files in a tree, ideal for sending into xargs.
For example:
# Change all "this" to "that" in all Perl files in a tree.
ack -f --perl | xargs perl -p -i -e's/this/that/g'
or if you prefer:
perl -p -i -e's/this/that/g' $(ack -f --perl)
Use -Q when in doubt about metacharacters
If you're searching for something with a regular expression
metacharacter, most often a period in a filename or IP address, add
the -Q to avoid false positives without all the backslashing. See
the following example for more...
Use ack to watch log files
Here's one I used the other day to find trouble spots for a website
visitor. The user had a problem loading troublesome.gif, so I
took the access log and scanned it with ack twice.
ack -Q aa.bb.cc.dd /path/to/access.log | ack -Q -B5 troublesome.gif
The first ack finds only the lines in the Apache log for the given
IP. The second finds the match on my troublesome GIF, and shows
the previous five lines from the log in each case.
Examples of --output
Following variables are useful in the expansion string:
- $&
-
The whole string matched by PATTERN.
- $1, $2, ...
-
The contents of the 1st, 2nd ... bracketed group in PATTERN.
- "$`"
-
The string before the match.
- "$'"
-
The string after the match.
For more details and other variables see
<http://perldoc.perl.org/perlvar.html#Variables-related-to-regular-expressions|perlvar>.
This example shows how to add text around a particular pattern
(in this case adding _ around word with ``e'')
ack2.pl "\w*e\w*" quick.txt --output="$`_$&_$'"
_The_ quick brown fox jumps over the lazy dog
The quick brown fox jumps _over_ the lazy dog
The quick brown fox jumps over _the_ lazy dog
This shows how to pick out particular parts of a match using ( ) within regular expression.
ack '=head(\d+)\s+(.*)' --output=' $1 : $2'
input file contains "=head1 NAME"
output "1 : NAME"
Share your knowledge
Join the ack-users mailing list. Send me your tips and I may add
them here.
FAQ
Why isn't ack finding a match in (some file)?
Probably because it's of a type that ack doesn't recognize. ack's
searching behavior is driven by filetype. If ack doesn't know
what kind of file it is, ack ignores the file.
Use the "-f" switch to see a list of files that ack will search
for you. You can use the "--show-types" switch to show which type
ack thinks each file is.
Wouldn't it be great if ack did search & replace?
No, ack will always be read-only. Perl has a perfectly good way
to do search & replace in files, using the "-i", "-p" and "-n"
switches.
You can certainly use ack to select your files to update. For
example, to change all ``foo'' to ``bar'' in all PHP files, you can do
this from the Unix shell:
$ perl -i -p -e's/foo/bar/g' $(ack -f --php)
Can I make ack recognize .xyz files?
Yes! Please see ``Defining your own types''. If you think
that ack should recognize a type by default, please see
``ENHANCEMENTS''.
There's already a program/package called ack.
Yes, I know.
Why is it called ack if it's called ack-grep?
The name of the program is ``ack''. Some packagers have called it
``ack-grep'' when creating packages because there's already a package
out there called ``ack'' that has nothing to do with this ack.
I suggest you make a symlink named ack that points to ack-grep
because one of the crucial benefits of ack is having a name that's
so short and simple to type.
To do that, run this with sudo or as root:
ln -s /usr/bin/ack-grep /usr/bin/ack
Alternatively, you could use a shell alias:
# bash/zsh
alias ack=ack-grep
# csh
alias ack ack-grep
What does ack mean?
Nothing. I wanted a name that was easy to type and that you could
pronounce as a single syllable.
Can I do multi-line regexes?
No, ack does not support regexes that match multiple lines. Doing
so would require reading in the entire file at a time.
If you want to see lines near your match, use the "--A", "--B"
and "--C" switches for displaying context.
Why is ack telling me I have an invalid option when searching for +foo?
ack treats command line options beginning with "+" or "-" as options; if you
would like to search for these, you may prefix your search term with "--" or
use the "--match" option. (However, don't forget that "+" is a regular
expression metacharacter!)
Why does ack '.{40000,}' fail? Isn't that a valid regex?
The Perl language limits the repetition quanitifier to 32K. You
can search for ".{32767}" but not ".{32768}".
ACKRC LOCATION SEMANTICS
Ack can load its configuration from many sources. This list
specifies the sources Ack looks for configuration; each one
that is found is loaded in the order specified here, and
each one overrides options set in any of the sources preceding
it. (For example, if I set --sort-files in my user ackrc, and
--nosort-files on the command line, the command line takes
precedence)
- •
-
Defaults are loaded from App::Ack::ConfigDefaults. This can be omitted
using "--ignore-ack-defaults".
- •
-
Global ackrc
Options are then loaded from the global ackrc. This is located at
"/etc/ackrc" on Unix-like systems.
Under Windows XP and earlier, the ackrc is at
"C:\Documents and Settings\All Users\Application Data\ackrc".
Under Windows Vista/7, the global ackrc is at
"C:\ProgramData"
The "--noenv" option prevents all ackrc files from being loaded.
- •
-
User ackrc
Options are then loaded from the user's ackrc. This is located at
"$HOME/.ackrc" on Unix-like systems.
Under Windows XP and earlier, the user's ackrc is at
"C:\Documents and Settings\$USER\Application Data\ackrc".
Under Windows Vista/7, the user's ackrc is at
<C:\Users\$USER\AppData\Roaming>.
If you want to load a different user-level ackrc, it may be specified
with the $ACKRC environment variable.
The "--noenv" option prevents all ackrc files from being loaded.
- •
-
Project ackrc
Options are then loaded from the project ackrc. The project ackrc is
the first ackrc file with the name ".ackrc" or "_ackrc", first searching
in the current directory, then the parent directory, then the grandparent
directory, etc. This can be omitted using "--noenv".
- •
-
--ackrc
The "--ackrc" option may be included on the command line to specify an
ackrc file that can override all others. It is consulted even if "--noenv"
is present.
- •
-
ACK_OPTIONS
Options are then loaded from the environment variable "ACK_OPTIONS". This can
be omitted using "--noenv".
- •
-
Command line
Options are then loaded from the command line.
DIFFERENCES BETWEEN ACK 1.X AND ACK 2.X
A lot of changes were made for ack 2; here is a list of them.
GENERAL CHANGES
- •
-
When no selectors are specified, ack 1.x only searches through files that
it can map to a file type. ack 2.x, by contrast, will search through
every regular, non-binary file that is not explicitly ignored via
--ignore-file or --ignore-dir. This is similar to the behavior of the
-a/--all option in ack 1.x.
- •
-
A more flexible filter system has been added, so that more powerful file types
may be created by the user. For details, please consult
``Defining your own types''.
- •
-
ack now loads multiple ackrc files; see ``ACKRC LOCATION SEMANTICS'' for
details.
- •
-
ack's default filter definitions aren't special; you may tell ack to
completely disregard them if you don't like them.
REMOVED OPTIONS
- •
-
Because of the change in default search behavior, the -a/--all and
-u/--unrestricted options have been removed. In addition, the
-k/--known-types option was added to cause ack to behave with
the default search behavior of ack 1.x.
- •
-
The -G option has been removed. Two regular expressions on the
command line was considered too confusing; to simulate -G's functionality,
you may use the new -x option to pipe filenames from one invocation of
ack into another.
- •
-
The --binary option has been removed.
- •
-
The --skipped option has been removed.
- •
-
The --text option has been removed.
- •
-
The --invert-file-match option has been removed. Instead, you may
use -v with -g.
CHANGED OPTIONS
- •
-
The options that modify the regular expression's behavior (-i, -w,
-Q, and -v) may now be used with -g.
ADDED OPTIONS
- •
-
--files-from was added so that a user may submit a list of filenames as
a list of files to search.
- •
-
-x was added to tell ack to accept a list of filenames via standard input;
this list is the list of filenames that will be used for the search.
- •
-
-s was added to tell ack to suppress error messages about non-existent or
unreadable files.
- •
-
--ignore-directory and --noignore-directory were added as aliases for
--ignore-dir and --noignore-dir respectively.
- •
-
--ignore-file was added so that users may specify patterns of files to
ignore (ex. /.*~$/).
- •
-
--dump was added to allow users to easily find out which options are
set where.
- •
-
--create-ackrc was added so that users may create custom ackrc files based
on the default settings loaded by ack, and so that users may easily view those
defaults.
- •
-
--type-del was added to selectively remove file type definitions.
- •
-
--ignore-ack-defaults was added so that users may ignore ack's default
options in favor of their own.
- •
-
--bar was added so ack users may consult Admiral Ackbar.
AUTHOR
Andy Lester, "<andy at petdance.com>"
BUGS
Please report any bugs or feature requests to the issues list at
Github: <https://github.com/petdance/ack2/issues>
ENHANCEMENTS
All enhancement requests MUST first be posted to the ack-users
mailing list at <http://groups.google.com/group/ack-users>. I
will not consider a request without it first getting seen by other
ack users. This includes requests for new filetypes.
There is a list of enhancements I want to make to ack in the ack
issues list at Github: <https://github.com/petdance/ack2/issues>
Patches are always welcome, but patches with tests get the most
attention.
SUPPORT
Support for and information about ack can be found at:
- •
-
The ack homepage
<http://beyondgrep.com/>
- •
-
The ack-users mailing list
<http://groups.google.com/group/ack-users>
- •
-
The ack issues list at Github
<https://github.com/petdance/ack2/issues>
- •
-
AnnoCPAN: Annotated CPAN documentation
<http://annocpan.org/dist/ack>
- •
-
CPAN Ratings
<http://cpanratings.perl.org/d/ack>
- •
-
Search CPAN
<http://search.cpan.org/dist/ack>
- •
-
Git source repository
<https://github.com/petdance/ack2>
ACKNOWLEDGEMENTS
How appropriate to have acknowledgements!
Thanks to everyone who has contributed to ack in any way, including
Stephen Thirlwall,
Jonah Bishop,
Chris Rebert,
Denis Howe,
Raul Gundin,
James McCoy,
Daniel Perrett,
Steven Lee,
Jonathan Perret,
Fraser Tweedale,
Raal Gundan,
Steffen Jaeckel,
Stephan Hohe,
Michael Beijen,
Alexandr Ciornii,
Christian Walde,
Charles Lee,
Joe McMahon,
John Warwick,
David Steinbrunner,
Kara Martens,
Volodymyr Medvid,
Ron Savage,
Konrad Borowski,
Dale Sedivic,
Michael McClimon,
Andrew Black,
Ralph Bodenner,
Shaun Patterson,
Ryan Olson,
Shlomi Fish,
Karen Etheridge,
Olivier Mengue,
Matthew Wild,
Scott Kyle,
Nick Hooey,
Bo Borgerson,
Mark Szymanski,
Marq Schneider,
Packy Anderson,
JR Boyens,
Dan Sully,
Ryan Niebur,
Kent Fredric,
Mike Morearty,
Ingmar Vanhassel,
Eric Van Dewoestine,
Sitaram Chamarty,
Adam James,
Richard Carlsson,
Pedro Melo,
AJ Schuster,
Phil Jackson,
Michael Schwern,
Jan Dubois,
Christopher J. Madsen,
Matthew Wickline,
David Dyck,
Jason Porritt,
Jjgod Jiang,
Thomas Klausner,
Uri Guttman,
Peter Lewis,
Kevin Riggle,
Ori Avtalion,
Torsten Blix,
Nigel Metheringham,
Gabor Szabo,
Tod Hagan,
Michael Hendricks,
AEvar Arnfjo.rd- Bjarmason,
Piers Cawley,
Stephen Steneker,
Elias Lutfallah,
Mark Leighton Fisher,
Matt Diephouse,
Christian Jaeger,
Bill Sully,
Bill Ricker,
David Golden,
Nilson Santos F. Jr,
Elliot Shank,
Merijn Broeren,
Uwe Voelker,
Rick Scott,
Ask Bjorn Hansen,
Jerry Gay,
Will Coleda,
Mike O'Regan,
Slaven ReziX,
Mark Stosberg,
David Alan Pisoni,
Adriano Ferreira,
James Keenan,
Leland Johnson,
Ricardo Signes,
Pete Krawczyk and
Rob Hoelz.
COPYRIGHT & LICENSE
Copyright 2005-2014 Andy Lester.
This program is free software; you can redistribute it and/or modify
it under the terms of the Artistic License v2.0.
See http://www.perlfoundation.org/artistic_license_2_0 or the LICENSE.md
file that comes with the ack distribution.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- FILE SELECTION
-
- DIRECTORY SELECTION
-
- WHEN TO USE GREP
-
- OPTIONS
-
- THE .ackrc FILE
-
- Defining your own types
-
- ENVIRONMENT VARIABLES
-
- AVAILABLE COLORS
-
- Foreground colors
-
- Background colors
-
- ACK & OTHER TOOLS
-
- Vim integration
-
- Emacs integration
-
- TextMate integration
-
- Shell and Return Code
-
- DEBUGGING ACK PROBLEMS
-
- Use --noenv
-
- Use -f to see what files have been selected
-
- Use --dump
-
- TIPS
-
- Use the .ackrc file.
-
- Use -f for working with big codesets
-
- Use -Q when in doubt about metacharacters
-
- Use ack to watch log files
-
- Examples of --output
-
- Share your knowledge
-
- FAQ
-
- Why isn't ack finding a match in (some file)?
-
- Wouldn't it be great if ack did search & replace?
-
- Can I make ack recognize .xyz files?
-
- There's already a program/package called ack.
-
- Why is it called ack if it's called ack-grep?
-
- What does ack mean?
-
- Can I do multi-line regexes?
-
- Why is ack telling me I have an invalid option when searching for +foo?
-
- Why does ack '.{40000,}' fail? Isn't that a valid regex?
-
- ACKRC LOCATION SEMANTICS
-
- DIFFERENCES BETWEEN ACK 1.X AND ACK 2.X
-
- GENERAL CHANGES
-
- REMOVED OPTIONS
-
- CHANGED OPTIONS
-
- ADDED OPTIONS
-
- AUTHOR
-
- BUGS
-
- ENHANCEMENTS
-
- SUPPORT
-
- ACKNOWLEDGEMENTS
-
- COPYRIGHT & LICENSE
-