🚵♂️
【tldr】超お手軽な情報ダイエットのススメ
はじめに
皆さんはtldrコマンドをご存知ですか？
私は先日、友人に教えてもらったのですが、物は試しということで実際に使ってみることにしました。
私の動作環境
- MacBook Air M1 2020
- MacOS Sonoma 14.5
tldrコマンドってなんやねん
tldrはToo Long; Didn't Read（訳:長すぎて読めなかった）の略語らしいです。
そして、tldrコマンドはmanコマンドの内容よりも簡略化されたマニュアルページを提供することを目的として作られたコマンドのようです。
詳細を知りたい方は、公式サイトやGithubを確認してください。
tldrコマンドをインストールする
私はmacOS上で以下のコマンドを実行し、Homebrew経由でtldrコマンドをインストールしました。
brew tap tldr-pages/tldr
brew install tldr
-
brew tap tldr-pages/tldr
Homebrewにtldrコマンドのリポジトリ（tldr-pages/tldr）を追加するコマンドです。これにより、Homebrewがリポジトリからパッケージをインストールできるようになります。 -
brew install tldr
実際にtldrコマンドをインストールするコマンドです。
tldrコマンドを使ってみた
実際にmanコマンドとtldrコマンドを比較して、tldrコマンドはどれくらい短くマニュアルページを表示するのか確認してみたいと思います。
また、今回はlsコマンドのマニュアルページを確認します。
manコマンドでlsコマンドのマニュアルページ確認
まず、manコマンドでマニュアルページを確認します。
また、分かりやすくするために以下のコマンドで、man lsの出力をman_ls_manual.txtというテキストファイルにリダイレクトして確認します。
man ls > man_ls_manual.txt
以下に、man_ls_manual.txtの内容を記載します。
man_ls_manual.txtの内容
LS(1) General Commands Manual LS(1)
NNAAMMEE
llss – list directory contents
SSYYNNOOPPSSIISS
llss [--@@AABBCCFFGGHHIILLOOPPRRSSTTUUWWaabbccddeeffgghhiikkllmmnnooppqqrrssttuuvvwwxxyy11%%,,] [----ccoolloorr=_w_h_e_n]
[--DD _f_o_r_m_a_t] [_f_i_l_e _._._.]
DDEESSCCRRIIPPTTIIOONN
For each operand that names a _f_i_l_e of a type other than directory, llss
displays its name as well as any requested, associated information. For
each operand that names a _f_i_l_e of type directory, llss displays the names
of files contained within that directory, as well as any requested,
associated information.
If no operands are given, the contents of the current directory are
displayed. If more than one operand is given, non-directory operands are
displayed first; directory and non-directory operands are sorted
separately and in lexicographical order.
The following options are available:
--@@ Display extended attribute keys and sizes in long (--ll) output.
--AA Include directory entries whose names begin with a dot (‘_.’)
except for _. and _._.. Automatically set for the super-user unless
--II is specified.
--BB Force printing of non-printable characters (as defined by
ctype(3) and current locale settings) in file names as \_x_x_x,
where _x_x_x is the numeric value of the character in octal. This
option is not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--CC Force multi-column output; this is the default when output is to
a terminal.
--DD _f_o_r_m_a_t
When printing in the long (--ll) format, use _f_o_r_m_a_t to format the
date and time output. The argument _f_o_r_m_a_t is a string used by
strftime(3). Depending on the choice of format string, this may
result in a different number of columns in the output. This
option overrides the --TT option. This option is not defined in
IEEE Std 1003.1-2008 (“POSIX.1”).
--FF Display a slash (‘/’) immediately after each pathname that is a
directory, an asterisk (‘*’) after each that is executable, an at
sign (‘@’) after each symbolic link, an equals sign (‘=’) after
each socket, a percent sign (‘%’) after each whiteout, and a
vertical bar (‘|’) after each that is a FIFO.
--GG Enable colorized output. This option is equivalent to defining
CLICOLOR or COLORTERM in the environment and setting
----ccoolloorr=_a_u_t_o. (See below.) This functionality can be compiled
out by removing the definition of COLORLS. This option is not
defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--HH Symbolic links on the command line are followed. This option is
assumed if none of the --FF, --dd, or --ll options are specified.
--II Prevent --AA from being automatically set for the super-user. This
option is not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--LL Follow all symbolic links to final target and list the file or
directory the link references rather than the link itself. This
option cancels the --PP option.
--OO Include the file flags in a long (--ll) output. This option is
incompatible with IEEE Std 1003.1-2008 (“POSIX.1”). See
chflags(1) for a list of file flags and their meanings.
--PP If argument is a symbolic link, list the link itself rather than
the object the link references. This option cancels the --HH and
--LL options.
--RR Recursively list subdirectories encountered.
--SS Sort by size (largest file first) before sorting the operands in
lexicographical order.
--TT When printing in the long (--ll) format, display complete time
information for the file, including month, day, hour, minute,
second, and year. The --DD option gives even more control over the
output format. This option is not defined in IEEE Std
1003.1-2008 (“POSIX.1”).
--UU Use time when file was created for sorting or printing. This
option is not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--WW Display whiteouts when scanning directories. This option is not
defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--aa Include directory entries whose names begin with a dot (‘_.’).
--bb As --BB, but use C escape codes whenever possible. This option is
not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--cc Use time when file status was last changed for sorting or
printing.
----ccoolloorr=_w_h_e_n
Output colored escape sequences based on _w_h_e_n, which may be set
to either aallwwaayyss, aauuttoo, or nneevveerr.
aallwwaayyss will make llss always output color. If TERM is unset or set
to an invalid terminal, then llss will fall back to explicit ANSI
escape sequences without the help of termcap(5). aallwwaayyss is the
default if ----ccoolloorr is specified without an argument.
aauuttoo will make llss output escape sequences based on termcap(5),
but only if stdout is a tty and either the --GG flag is specified
or the COLORTERM environment variable is set and not empty.
nneevveerr will disable color regardless of environment variables.
nneevveerr is the default when neither ----ccoolloorr nor --GG is specified.
For compatibility with GNU coreutils, llss supports yyeess or ffoorrccee as
equivalent to aallwwaayyss, nnoo or nnoonnee as equivalent to nneevveerr, and ttttyy
or iiff--ttttyy as equivalent to aauuttoo.
--dd Directories are listed as plain files (not searched recursively).
--ee Print the Access Control List (ACL) associated with the file, if
present, in long (--ll) output.
--ff Output is not sorted. This option turns on --aa. It also negates
the effect of the --rr, --SS and --tt options. As allowed by IEEE Std
1003.1-2008 (“POSIX.1”), this option has no effect on the --dd, --ll,
--RR and --ss options.
--gg This option has no effect. It is only available for
compatibility with 4.3BSD, where it was used to display the group
name in the long (--ll) format output. This option is incompatible
with IEEE Std 1003.1-2008 (“POSIX.1”).
--hh When used with the --ll option, use unit suffixes: Byte, Kilobyte,
Megabyte, Gigabyte, Terabyte and Petabyte in order to reduce the
number of digits to four or fewer using base 2 for sizes. This
option is not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--ii For each file, print the file's file serial number (inode
number).
--kk This has the same effect as setting environment variable
BLOCKSIZE to 1024, except that it also nullifies any --hh options
to its left.
--ll (The lowercase letter “ell”.) List files in the long format, as
described in the _T_h_e _L_o_n_g _F_o_r_m_a_t subsection below.
--mm Stream output format; list files across the page, separated by
commas.
--nn Display user and group IDs numerically rather than converting to
a user or group name in a long (--ll) output. This option turns on
the --ll option.
--oo List in long format, but omit the group id.
--pp Write a slash (‘/’) after each filename if that file is a
directory.
--qq Force printing of non-graphic characters in file names as the
character ‘?’; this is the default when output is to a terminal.
--rr Reverse the order of the sort.
--ss Display the number of blocks used in the file system by each
file. Block sizes and directory totals are handled as described
in _T_h_e _L_o_n_g _F_o_r_m_a_t subsection below, except (if the long format
is not also requested) the directory totals are not output when
the output is in a single column, even if multi-column output is
requested. (--ll) format, display complete time information for
the file, including month, day, hour, minute, second, and year.
The --DD option gives even more control over the output format.
This option is not defined in IEEE Std 1003.1-2008 (“POSIX.1”).
--tt Sort by descending time modified (most recently modified first).
If two files have the same modification timestamp, sort their
names in ascending lexicographical order. The --rr option reverses
both of these sort orders.
Note that these sort orders are contradictory: the time sequence
is in descending order, the lexicographical sort is in ascending
order. This behavior is mandated by IEEE Std 1003.2 (“POSIX.2”).
This feature can cause problems listing files stored with
sequential names on FAT file systems, such as from digital
cameras, where it is possible to have more than one image with
the same timestamp. In such a case, the photos cannot be listed
in the sequence in which they were taken. To ensure the same
sort order for time and for lexicographical sorting, set the
environment variable LS_SAMESORT or use the --yy option. This
causes llss to reverse the lexicographical sort order when sorting
files with the same modification timestamp.
--uu Use time of last access, instead of time of last modification of
the file for sorting (--tt) or long printing (--ll).
--vv Force unedited printing of non-graphic characters; this is the
default when output is not to a terminal.
--ww Force raw printing of non-printable characters. This is the
default when output is not to a terminal. This option is not
defined in IEEE Std 1003.1-2001 (“POSIX.1”).
--xx The same as --CC, except that the multi-column output is produced
with entries sorted across, rather than down, the columns.
--yy When the --tt option is set, sort the alphabetical output in the
same order as the time output. This has the same effect as
setting LS_SAMESORT. See the description of the --tt option for
more details. This option is not defined in IEEE Std 1003.1-2001
(“POSIX.1”).
--%% Distinguish dataless files and directories with a '%' character
in long (--ll) output, and don't materialize dataless directories
when listing them.
--11 (The numeric digit “one”.) Force output to be one entry per line.
This is the default when output is not to a terminal.
--, (Comma) When the --ll option is set, print file sizes grouped and
separated by thousands using the non-monetary separator returned
by localeconv(3), typically a comma or period. If no locale is
set, or the locale does not have a non-monetary separator, this
option has no effect. This option is not defined in IEEE Std
1003.1-2001 (“POSIX.1”).
The --11, --CC, --xx, and --ll options all override each other; the last one
specified determines the format used.
The --cc, --uu, and --UU options all override each other; the last one
specified determines the file time used.
The --SS and --tt options override each other; the last one specified
determines the sort order used.
The --BB, --bb, --ww, and --qq options all override each other; the last one
specified determines the format used for non-printable characters.
The --HH, --LL and --PP options all override each other (either partially or
fully); they are applied in the order specified.
By default, llss lists one entry per line to standard output; the
exceptions are to terminals or when the --CC or --xx options are specified.
File information is displayed with one or more ⟨blank⟩s separating the
information associated with the --ii, --ss, and --ll options.
TThhee LLoonngg FFoorrmmaatt
If the --ll option is given, the following information is displayed for
each file: file mode, number of links, owner name, group name, number of
bytes in the file, abbreviated month, day-of-month file was last
modified, hour file last modified, minute file last modified, and the
pathname. If the file or directory has extended attributes, the
permissions field printed by the --ll option is followed by a '@'
character. Otherwise, if the file or directory has extended security
information (such as an access control list), the permissions field
printed by the --ll option is followed by a '+' character. If the --%%
option is given, a '%' character follows the permissions field for
dataless files and directories, possibly replacing the '@' or '+'
character.
If the modification time of the file is more than 6 months in the past or
future, and the --DD or --TT are not specified, then the year of the last
modification is displayed in place of the hour and minute fields.
If the owner or group names are not a known user or group name, or the --nn
option is given, the numeric ID's are displayed.
If the file is a character special or block special file, the device
number for the file is displayed in the size field. If the file is a
symbolic link the pathname of the linked-to file is preceded by “->”.
The listing of a directory's contents is preceded by a labeled total
number of blocks used in the file system by the files which are listed as
the directory's contents (which may or may not include _. and _._. and other
files which start with a dot, depending on other options).
The default block size is 512 bytes. The block size may be set with
option --kk or environment variable BLOCKSIZE. Numbers of blocks in the
output will have been rounded up so the numbers of bytes is at least as
many as used by the corresponding file system blocks (which might have a
different size).
The file mode printed under the --ll option consists of the entry type and
the permissions. The entry type character describes the type of file, as
follows:
-- Regular file.
bb Block special file.
cc Character special file.
dd Directory.
ll Symbolic link.
pp FIFO.
ss Socket.
ww Whiteout.
The next three fields are three characters each: owner permissions, group
permissions, and other permissions. Each field has three character
positions:
1. If rr, the file is readable; if --, it is not readable.
2. If ww, the file is writable; if --, it is not writable.
3. The first of the following that applies:
SS If in the owner permissions, the file is not
executable and set-user-ID mode is set. If in the
group permissions, the file is not executable and
set-group-ID mode is set.
ss If in the owner permissions, the file is
executable and set-user-ID mode is set. If in the
group permissions, the file is executable and
setgroup-ID mode is set.
xx The file is executable or the directory is
searchable.
-- The file is neither readable, writable,
executable, nor set-user-ID nor set-group-ID mode,
nor sticky. (See below.)
These next two apply only to the third character in the last
group (other permissions).
TT The sticky bit is set (mode 1000), but not execute
or search permission. (See chmod(1) or
sticky(7).)
tt The sticky bit is set (mode 1000), and is
searchable or executable. (See chmod(1) or
sticky(7).)
The next field contains a plus (‘+’) character if the file has an ACL, or
a space (‘ ’) if it does not. The llss utility does not show the actual
ACL unless the --ee option is used in conjunction with the --ll option.
EENNVVIIRROONNMMEENNTT
The following environment variables affect the execution of llss:
BLOCKSIZE If this is set, its value, rounded up to 512 or down
to a multiple of 512, will be used as the block size
in bytes by the --ll and --ss options. See _T_h_e _L_o_n_g
_F_o_r_m_a_t subsection for more information.
CLICOLOR Use ANSI color sequences to distinguish file types.
See LSCOLORS below. In addition to the file types
mentioned in the --FF option some extra attributes
(setuid bit set, etc.) are also displayed. The
colorization is dependent on a terminal type with the
proper termcap(5) capabilities. The default “cons25”
console has the proper capabilities, but to display
the colors in an xterm(1), for example, the TERM
variable must be set to “xterm-color”. Other
terminal types may require similar adjustments.
Colorization is silently disabled if the output is
not directed to a terminal unless the CLICOLOR_FORCE
variable is defined or ----ccoolloorr is set to “always”.
CLICOLOR_FORCE Color sequences are normally disabled if the output
is not directed to a terminal. This can be
overridden by setting this variable. The TERM
variable still needs to reference a color capable
terminal however otherwise it is not possible to
determine which color sequences to use.
COLORTERM See description for CLICOLOR above.
COLUMNS If this variable contains a string representing a
decimal integer, it is used as the column position
width for displaying multiple-text-column output.
The llss utility calculates how many pathname text
columns to display based on the width provided. (See
--CC and --xx.)
LANG The locale to use when determining the order of day
and month in the long --ll format output. See
environ(7) for more information.
LSCOLORS The value of this variable describes what color to
use for which attribute when colors are enabled with
CLICOLOR or COLORTERM. This string is a
concatenation of pairs of the format _f_b, where _f is
the foreground color and _b is the background color.
The color designators are as follows:
aa black
bb red
cc green
dd brown
ee blue
ff magenta
gg cyan
hh light grey
AA bold black, usually shows up as dark grey
BB bold red
CC bold green
DD bold brown, usually shows up as yellow
EE bold blue
FF bold magenta
GG bold cyan
HH bold light grey; looks like bright white
xx default foreground or background
Note that the above are standard ANSI colors. The
actual display may differ depending on the color
capabilities of the terminal in use.
The order of the attributes are as follows:
1. directory
2. symbolic link
3. socket
4. pipe
5. executable
6. block special
7. character special
8. executable with setuid bit set
9. executable with setgid bit set
10. directory writable to others, with sticky
bit
11. directory writable to others, without
sticky bit
The default is "exfxcxdxbxegedabagacad", i.e., blue
foreground and default background for regular
directories, black foreground and red background for
setuid executables, etc.
LS_COLWIDTHS If this variable is set, it is considered to be a
colon-delimited list of minimum column widths.
Unreasonable and insufficient widths are ignored
(thus zero signifies a dynamically sized column).
Not all columns have changeable widths. The fields
are, in order: inode, block count, number of links,
user name, group name, flags, file size, file name.
LS_SAMESORT If this variable is set, the --tt option sorts the
names of files with the same modification timestamp
in the same sense as the time sort. See the
description of the --tt option for more details.
TERM The CLICOLOR and COLORTERM functionality depends on a
terminal type with color capabilities.
TZ The timezone to use when displaying dates. See
environ(7) for more information.
EEXXIITT SSTTAATTUUSS
The llss utility exits 0 on success, and >0 if an error occurs.
EEXXAAMMPPLLEESS
List the contents of the current working directory in long format:
$ ls -l
In addition to listing the contents of the current working directory in
long format, show inode numbers, file flags (see chflags(1)), and suffix
each filename with a symbol representing its file type:
$ ls -lioF
List the files in _/_v_a_r_/_l_o_g, sorting the output such that the most
recently modified entries are printed first:
$ ls -lt /var/log
CCOOMMPPAATTIIBBIILLIITTYY
The group field is now automatically included in the long listing for
files in order to be compatible with the IEEE Std 1003.2 (“POSIX.2”)
specification.
LLEEGGAACCYY DDEESSCCRRIIPPTTIIOONN
In legacy mode, the --ff option does not turn on the --aa option and the --gg,
--nn, and --oo options do not turn on the --ll option.
Also, the --oo option causes the file flags to be included in a long (-l)
output; there is no --OO option.
When --HH is specified (and not overridden by --LL or --PP) and a file argument
is a symlink that resolves to a non-directory file, the output will
reflect the nature of the link, rather than that of the file. In legacy
operation, the output will describe the file.
For more information about legacy mode, see compat(5).
SSEEEE AALLSSOO
chflags(1), chmod(1), sort(1), xterm(1), localeconv(3), strftime(3),
strmode(3), compat(5), termcap(5), sticky(7), symlink(7)
SSTTAANNDDAARRDDSS
With the exception of options --gg, --nn and --oo, the llss utility conforms to
IEEE Std 1003.1-2001 (“POSIX.1”) and IEEE Std 1003.1-2008 (“POSIX.1”).
The options --BB, --DD, --GG, --II, --TT, --UU, --WW, --ZZ, --bb, --hh, --ww, --yy and --, are
non-standard extensions.
The ACL support is compatible with IEEE Std 1003.2c (“POSIX.2c”) Draft 17
(withdrawn).
HHIISSTTOORRYY
An llss command appeared in Version 1 AT&T UNIX.
BBUUGGSS
To maintain backward compatibility, the relationships between the many
options are quite complex.
The exception mentioned in the --ss option description might be a feature
that was based on the fact that single-column output usually goes to
something other than a terminal. It is debatable whether this is a
design bug.
IEEE Std 1003.2 (“POSIX.2”) mandates opposite sort orders for files with
the same timestamp when sorting with the --tt option.
macOS 14.5 August 31, 2020 macOS 14.5
私は読む気が失せました。Too Long; Didn't Readすぎます⋯
tldrコマンドでlsコマンドのマニュアルページ確認
次に、tldrコマンドでマニュアルページを確認します。
また、manコマンドと同様に、分かりやすくするために以下のコマンドで、tldr lsの出力をtldr_ls_manual.txtというテキストファイルにリダイレクトして確認します。
tldr ls > tldr_ls_manual.txt
以下に、tldr_ls_manual.txtの内容を記載します。
さぁ、どうだ！
tldr_ls_manual.txtの内容
ls
List directory contents.
More information: <https://www.gnu.org/software/coreutils/ls>.
- List files one per line:
ls -1
- List all files, including hidden files:
ls -a
- List all files, with trailing `/` added to directory names:
ls -F
- Long format list (permissions, ownership, size, and modification date) of all files:
ls -la
- Long format list with size displayed using human-readable units (KiB, MiB, GiB):
ls -lh
- Long format list sorted by size (descending) recursively:
ls -lSR
- Long format list of all files, sorted by modification date (oldest first):
ls -ltr
- Only list directories:
ls -d */
なんだこの圧倒的な短さは！革命的すぎる！！！
さいごに
ここまで記事を読んでくださり、ありがとうございました！
今回は、tldrコマンドについて紹介しました。
普段はtldrコマンドでマニュアルページを確認し、より深く知りたくなった際にmanコマンドを用いるといったように使い分けると良いかもしれません。
興味を持った方は、ぜひtldrコマンドを利用してマニュアルページを確認してみてください！
皆さんも素敵なハッピーtldrライフを！！！🌸
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