(bash): The most useless commands (11)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix
6. cal
7. rig 
8. pi
9. figlet

here a packages called filters which comes with such commands:

$ echo hello my friend | jethro
hello mah friend
$ echo hello my friend | chef
hellu my freeund
$ echo hello my friend | kraut
hello mein friend

Manpage:

DESCRIPTION
       All  of  these  programs are filters to do all sorts of strange things to text.  No personal, racial,
       religious or societal slurs are intended. For amusement only.

       All the filters read input from stdin, change it, and write the filtered text to stdout. Some filters
       also support reading from files and writing to stdout.

       b1ff   The B1FF filter

       lolcat As seen in internet gifs everywhere.

       cockney
              Cockney English

       chef   convert English on stdin to Mock Swedish on stdout

       eleet  K3wl hacker slang

       fanboy Speak  like  a  fanboy.  Filters  out  extraneous  words and focuses on the words fans use. By default, it will speak like a fan of git/Linus/linux development.  To  change  this,  pass  as parameters  the  words that the fanboy typically uses. Alternatively, pass the name of a topic that typically has fanboys to use a predefined word list.

       fudd   Elmer Fudd

       jethro Hillbilly text filter

       jive   Jive English

       jibberish
              Runs text through a random selection of the rest of the filters, to make really weird output.

       ken    English into Cockney, featuring (dubious) rhyming slang for a lot of computer terminology.

       kraut  Generates text with a bad German accent.

       kenny  Generates text as spoken by Kenny on South Park.

       ky00te This program places a very cute (and familiar to FurryMuck fans) accent on any text file.

       nethackify
              Wiped out text like can be found in nethack.

       newspeak
              A-la-1984

       censor CDA-ize text

       nyc    Brooklyn English

       pirate Talk like a pirate.

       rasterman
              Makes text look like it came from the keyboard of Carsten Haitzler.
      scottish
              Fake scottish (dwarven) accent filter, inspired by the character "Durkon" from  Order  of  the
              Stick.

       spammer
              Turns honest text into something that is liable to be flagged as spam.

       scramble
              Scramble  the  "inner"  letters  of each word in the input into a random order.  The resulting
              text is still strangely readable.

       studly Studly caps.

       uniencode
              Use glorious unicode to the fullest possible extent. As seen previously in many man pages.

       upside-down
              Flips text upside down. Stand on your head and squint to read the output.

(bash): The most useless commands(10)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix
6. cal
7. rig 
8. pi

here another pretty useless command:

~$ figlet apt-get update
             _                   _                     _       _      
  __ _ _ __ | |_       __ _  ___| |_   _   _ _ __   __| | __ _| |_ ___
 / _` | '_ \| __|____ / _` |/ _ \ __| | | | | '_ \ / _` |/ _` | __/ _ \
| (_| | |_) | ||_____| (_| |  __/ |_  | |_| | |_) | (_| | (_| | ||  __/
 \__,_| .__/ \__|     \__, |\___|\__|  \__,_| .__/ \__,_|\__,_|\__\___|
      |_|             |___/                 |_|                        

Manpage:

DESCRIPTION
       FIGlet  prints  its input using large characters (called ``FIGcharacters'')made up of ordinary screen
       characters (called ``sub-characters'').  FIGlet output is generally reminiscent of the sort of ``sig‐
       natures''  many  people like to put at the end of e-mail and UseNet messages.  It is also reminiscent
       of the output of some banner programs, although it is oriented normally, not sideways.

       FIGlet can print in a variety of fonts, both left-to-right and right-to-left, with adjacent  FIGchar‐
       acters  kerned  and ``smushed'' together in various ways.  FIGlet fonts are stored in separate files,
       which can be identified by the suffix ``.flf''.  In systems with UTF-8 support FIGlet may  also  sup‐
       port  TOIlet  ``.tlf''  fonts.  Most FIGlet font files will be stored in FIGlet's default font direc‐
       tory.

       FIGlet can also use ``control files'', which tell it to map certain input characters to certain other
       characters,  similar to the Unix tr command.  Control files can be identified by the suffix ``.flc''.
       Most FIGlet control files will be stored in FIGlet's default font directory.

       You can store FIGlet fonts and control files in compressed form.  See COMPRESSED FONTS.

(bash): The most useless commands (9)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix
6. cal
7. rig

here another pretty useless command:

$ pi 10
3.141592653

Manpage:

DESCRIPTION
       The  pi  command  prints  100 decimal digits of Archimedes' constant pi or a number of
       digits specified by an integer parameter on the command line.

(bash): The most useless commands (8)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix
6. cal

 i found another funny command:

rig

Its manpage tells the following:

DESCRIPTION
       Rig  is a utility that will piece together a random first name, last name, street num‐
       ber and address, along with a geographically consistant (ie, they all match  the  same
       area) city, state, ZIP code, and area code.

       It is suitable for such applications as feeding the NY times registration page to fend
       off junk (snail) mail and telemarketers, or for registering  on  BBS's  to  which  you
       don't wish to reveal your real information.

I am not sure if this tool is banned by the NSA ;-) but here we go:

schroff@zerberus:~$ rig
Carmelo Suarez
947 East Parson St
Alton, IL  62002
(708) xxx-xxxx
schroff@zerberus:~$ rig
Janna Stewart
970 Potter Rd
Auburn, NY  13021
(315) xxx-xxxx
schroff@zerberus:~$ rig
Bernadine Collins
27 Willow Rd
Seattle, WA  98109
(206) xxx-xxxx

(bash): The most useless commands (7)

After talking about

1. rev
2. yes
3. sl
4. cowsay
5. cmatrix

here another pretty useless command:

cal

Today with every smartphone having its own calendar app or every e-mail program with integrated time planning function this command is no more needed. The manpage says:

NAME
     cal, ncal — displays a calendar and the date of Easter

And here we go:

$ cal 2000
                            2000
       Januar               Februar                 März        
So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa
                   1         1  2  3  4  5            1  2  3  4
 2  3  4  5  6  7  8   6  7  8  9 10 11 12   5  6  7  8  9 10 11
 9 10 11 12 13 14 15  13 14 15 16 17 18 19  12 13 14 15 16 17 18
16 17 18 19 20 21 22  20 21 22 23 24 25 26  19 20 21 22 23 24 25
23 24 25 26 27 28 29  27 28 29              26 27 28 29 30 31  
30 31                                                          
       April                  Mai                   Juni        
So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa
                   1      1  2  3  4  5  6               1  2  3
 2  3  4  5  6  7  8   7  8  9 10 11 12 13   4  5  6  7  8  9 10
 9 10 11 12 13 14 15  14 15 16 17 18 19 20  11 12 13 14 15 16 17
16 17 18 19 20 21 22  21 22 23 24 25 26 27  18 19 20 21 22 23 24
23 24 25 26 27 28 29  28 29 30 31           25 26 27 28 29 30  
30                                                              
        Juli                 August              September      
So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa
                   1         1  2  3  4  5                  1  2
 2  3  4  5  6  7  8   6  7  8  9 10 11 12   3  4  5  6  7  8  9
 9 10 11 12 13 14 15  13 14 15 16 17 18 19  10 11 12 13 14 15 16
16 17 18 19 20 21 22  20 21 22 23 24 25 26  17 18 19 20 21 22 23
23 24 25 26 27 28 29  27 28 29 30 31        24 25 26 27 28 29 30
30 31                                                          
      Oktober               November              Dezember      
So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa  So Mo Di Mi Do Fr Sa
 1  2  3  4  5  6  7            1  2  3  4                  1  2
 8  9 10 11 12 13 14   5  6  7  8  9 10 11   3  4  5  6  7  8  9
15 16 17 18 19 20 21  12 13 14 15 16 17 18  10 11 12 13 14 15 16
22 23 24 25 26 27 28  19 20 21 22 23 24 25  17 18 19 20 21 22 23
29 30 31              26 27 28 29 30        24 25 26 27 28 29 30
                                            31                    

 Or "the date of Easter":

$ ncal -e 2018
 1 April 2018

(bash): The most useless commands (6)

After talking about

1. rev
2. yes
3. sl
4. cowsay

 i found another funny command:

cmatrix

The manpage says:

NAME
       CMatrix - simulates the display from "The Matrix"

and it is true:

(bash): The most useless commands (5) | bash builtin commands

[if you are looking for the builtin commands of jshell: read this posting]

In a comment Albert Godfrind pointed out, that the commands i was talking about like

1. rev
2. yes
3. sl
4. cowsay

are not really bash commands (in a way that they will be installed within the installation of the bash shell). They are commands, which can be used from on every shell. So my headline is a little bit missleading - thanks for this notice.

Just for clarification here a list with all bash builtin commands:

• alias
• bind
• builtin
• caller
• command
• declare
• echo
• enable
• help
• let
• local
• logout
• mapfile
• printf
• read
• readarray
• source
• type
• typeset
• ulimit
• unalias

and the bourne shell builtins:

• break
• cd
• continue
• eval
• exec
• export
• getopts
• hash
• pwd
• readonly
• return
• shift
• test
• times
• trap
• umask
• unset

Still missing:

• Job Control Builtins
  like bg, fg, kill, ...
• Directory Stack Builtins
  dirs, popd, pushd
• History Builtins
  fc, history
• Programmable Completion Builtins
  compgen, complete, compopt

Bash: The most useless commands (4)

The blog statistics show, that there are many people reading the posts about useless commands. And there is the next candidate:

cowsay

Now you are thinking, what is cowsay?

DESCRIPTION
       Cowsay  generates  an  ASCII picture of a cow saying something provided by the user.  If run with no arguments, it accepts standard input, word-wraps
       the message given at about 40 columns, and prints the cow saying the given message on standard output.

?

Okay. Here we go:

$ echo what a cool command | cowsay
 _____________________
< what a cool command >
 ---------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

One thing to add here: moo 

Bash: The most useless commands (3)

The blog statistics show, that there are many people reading the posts about useless commands. And there is the next candidate, suggested by an anonymous comment:

sl

This is my most hated program on a shell. Why?

NAME
sl − display animations aimed to correct users who accidentally enter sl instead of ls.

and this program is not interruptable by ctrl-c.
It shows a train running from the left to the right

and blocks your shell for at least 2-3 seconds (depends on the width of your shell window):

$ time sl
real 0m3.347s

Bash: The most useless commands (2)

The last posting about useless commands for bash discussed the command

rev

. One nice comment pointed out, that the rev command can be used for searching inside logfiles (Thanks to phoxis.org).

Like it was said there, the command

yes

looks even more useless:

NAME
       yes - output a string repeatedly until killed
SYNOPSIS
       yes [STRING]...

Ok - it can be used for scripts to answer call backs. But which kind of script needs always the same answer? (and commands like "apt-get" support this via the option "-y".

Any other suggestions about useless bash commands?

Bash: The most useless command

After many years working with the bourne again shell i  am still learning some commands, which i never used.
I am completely convinced that i discovered the most useless command:

rev

The manpage says:

rev - reverse lines characterwise

 Is there anything, where i can use this command?

Ok. I can check if a word is a palindrome (like 123321 or otto):

#!/bin/bash
# Shell script to test if a string is a palindrome
# This simply uses the 'rev' command found in util-linux-ng package
# and checks if the reverse of the string is same as the original
 echo "Enter a String : "
read string
if [ "$(echo $string | rev)" = "$string" ]
then
 echo "\"$string\" IS a Palindrome"
else
 echo "\"$string\" IS NOT a Palindrome"
fi

This script i found in here.

Has anyone used the rev command for something reasonable?
Please write a comment!

More useless commands can be found here.