Introduction to Bash

Text Editors, Process and Redirection

Mauricio Sevilla


email= j.sevillam@uniandes.edu.co

01.28.19

Review

We have already talk about the terminal and some of its uses.

What have we learned?

  • Differences between GUI and CLI

  • Some instructions such as

    • more
    • less
    • cat
    • cd
    • cp
    • ls
    • wc
    • pwd

Do you remember how to use them?

First, you should open Binder, a new link is available on our repository

github.com/jmsevillam/Herramientas-Computacionales-UniAndes

There you will find installed the packages we are going to use during the classes.

After that, open a terminal window.

Last class, we created a small file, by using the operator >,

Question

What is the difference between > and >>.

let us explore it

Let us create a file by using > as we have already done,

In [1]:
echo this is a test > test.txt

We learned that now on the file there must be saved this is a test, try to view the content

In [2]:
cat test.txt
this is a test

But, what if we want to add a new line,

In [3]:
echo this is a new test > test.txt

Again, we can see the file

In [4]:
cat test.txt
this is a new test

The second instruction erased the first one, that wasn't what we wanted, let's do it different

Let's remove the file, just in order to be sure we are creating a new one

In [5]:
rm test.txt

Again, we can start in the same way we did before

In [6]:
echo this is a test > test.txt

we can open the file

In [7]:
cat test.txt
this is a test

if we use >> instead of >

In [8]:
echo this is a new test >> test.txt

and print the result

In [10]:
cat test.txt
this is a test
this is a new test

Conclusions


The use uf > and >> depends strongly on what we want to do.

> replaces the content of a file, if doesn't exist, creates it. >> Adds a new line of the file.

This process is called Redirection.

Some times we may be interested on doing a bigger file, and using a line by line addition is not the best option, there are some programs which can help us to make this task easier.

Right now, there are may of these programs, some of the most used are

>

  • vi
  • vim
  • emacs
  • nano

try them.

In [19]:
man vim
VIM(1)                                                                  VIM(1)



NAME
       vim - Vi IMproved, a programmer's text editor

SYNOPSIS
       vim [options] [file ..]
       vim [options] -
       vim [options] -t tag
       vim [options] -q [errorfile]

       ex
       view
       gvim gview evim eview
       rvim rview rgvim rgview

DESCRIPTION
       Vim  is a text editor that is upwards compatible to Vi.  It can be used
       to edit all kinds of plain text.  It is especially useful  for  editing
       programs.

       There  are a lot of enhancements above Vi: multi level undo, multi win-
       dows and buffers, syntax highlighting, command line  editing,  filename
       completion,   on-line   help,   visual  selection,  etc..   See  ":help
       vi_diff.txt" for a summary of the differences between Vim and Vi.

       While running Vim a lot of help can be obtained from the  on-line  help
       system,  with the ":help" command.  See the ON-LINE HELP section below.

       Most often Vim is started to edit a single file with the command

            vim file

       More generally Vim is started with:

            vim [options] [filelist]

       If the filelist is missing, the editor will start with an empty buffer.
       Otherwise  exactly  one out of the following four may be used to choose
       one or more files to be edited.

       file ..     A list of filenames.  The first one  will  be  the  current
                   file  and  read  into the buffer.  The cursor will be posi-
                   tioned on the first line of the buffer.  You can get to the
                   other  files with the ":next" command.  To edit a file that
                   starts with a dash, precede the filelist with "--".

       -           The file to edit is read from  stdin.   Commands  are  read
                   from stderr, which should be a tty.

       -t {tag}    The file to edit and the initial cursor position depends on
                   a "tag", a sort of goto label.  {tag} is looked up  in  the
                   tags file, the associated file becomes the current file and
                   the associated command is executed.  Mostly  this  is  used
                   for  C  programs,  in  which case {tag} could be a function
                   name.  The effect is that the file containing that function
                   becomes  the  current  file and the cursor is positioned on
                   the start of the function.  See ":help tag-commands".

       -q [errorfile]
                   Start in quickFix mode.  The file [errorfile] is  read  and
                   the  first  error is displayed.  If [errorfile] is omitted,
                   the  filename  is  obtained  from  the  'errorfile'  option
                   (defaults  to  "AztecC.Err"  for the Amiga, "errors.err" on
                   other systems).  Further errors can be jumped to  with  the
                   ":cn" command.  See ":help quickfix".

       Vim behaves differently, depending on the name of the command (the exe-
       cutable may still be the same file).

       vim       The "normal" way, everything is default.

       ex        Start in Ex mode.  Go to Normal mode with the ":vi"  command.
                 Can also be done with the "-e" argument.

       view      Start  in read-only mode.  You will be protected from writing
                 the files.  Can also be done with the "-R" argument.

       gvim gview
                 The GUI version.  Starts a new window.  Can also be done with
                 the "-g" argument.

       evim eview
                 The GUI version in easy mode.  Starts a new window.  Can also
                 be done with the "-y" argument.

       rvim rview rgvim rgview
                 Like the above, but with restrictions.  It will not be possi-
                 ble  to  start  shell  commands, or suspend Vim.  Can also be
                 done with the "-Z" argument.

OPTIONS
       The options may be given in  any  order,  before  or  after  filenames.
       Options without an argument can be combined after a single dash.

       +[num]      For  the  first  file the cursor will be positioned on line
                   "num".  If "num" is missing, the cursor will be  positioned
                   on the last line.

       +/{pat}     For  the  first  file  the cursor will be positioned in the
                   line with  the  first  occurrence  of  {pat}.   See  ":help
                   search-pattern" for the available search patterns.

       +{command}

       -c {command}
                   {command}  will  be  executed after the first file has been
                   read.  {command} is interpreted as an Ex command.   If  the
                   {command}  contains  spaces  it  must be enclosed in double
                   quotes (this depends on the shell that is used).   Example:
                   Vim "+set si" main.c
                   Note: You can use up to 10 "+" or "-c" commands.

       -S {file}   {file}  will be sourced after the first file has been read.
                   This is equivalent to -c "source  {file}".   {file}  cannot
                   start with '-'.  If {file} is omitted "Session.vim" is used
                   (only works when -S is the last argument).

       --cmd {command}
                   Like using "-c", but the command is  executed  just  before
                   processing  any  vimrc file.  You can use up to 10 of these
                   commands, independently from "-c" commands.

       -A          If Vim has been compiled with ARABIC  support  for  editing
                   right-to-left  oriented  files and Arabic keyboard mapping,
                   this option starts Vim in Arabic  mode,  i.e.  'arabic'  is
                   set.  Otherwise an error message is given and Vim aborts.

       -b          Binary  mode.  A few options will be set that makes it pos-
                   sible to edit a binary or executable file.

       -C          Compatible.  Set the 'compatible' option.  This  will  make
                   Vim  behave  mostly  like  Vi,  even  though  a .vimrc file
                   exists.

       -d          Start in diff mode.  There should be  two,  three  or  four
                   file  name arguments.  Vim will open all the files and show
                   differences between them.  Works like vimdiff(1).

       -d {device} Open {device} for use as a terminal.  Only  on  the  Amiga.
                   Example: "-d con:20/30/600/150".

       -D          Debugging.   Go  to debugging mode when executing the first
                   command from a script.

       -e          Start Vim in Ex mode, just like the executable  was  called
                   "ex".

       -E          Start Vim in improved Ex mode, just like the executable was
                   called "exim".

       -f          Foreground.  For the GUI version, Vim  will  not  fork  and
                   detach from the shell it was started in.  On the Amiga, Vim
                   is not restarted to open a new window.  This option  should
                   be  used  when  Vim is executed by a program that will wait
                   for the edit session to finish (e.g. mail).  On  the  Amiga
                   the ":sh" and ":!" commands will not work.

       --nofork    Foreground.   For  the  GUI  version, Vim will not fork and
                   detach from the shell it was started in.

       -F          If Vim has been compiled with  FKMAP  support  for  editing
                   right-to-left  oriented  files  and Farsi keyboard mapping,
                   this option starts Vim in  Farsi  mode,  i.e.  'fkmap'  and
                   'rightleft'  are  set.  Otherwise an error message is given
                   and Vim aborts.

       -g          If Vim has been compiled  with  GUI  support,  this  option
                   enables  the  GUI.   If  no GUI support was compiled in, an
                   error message is given and Vim aborts.

       -h          Give a bit of help about the  command  line  arguments  and
                   options.  After this Vim exits.

       -H          If Vim has been compiled with RIGHTLEFT support for editing
                   right-to-left oriented files and Hebrew  keyboard  mapping,
                   this  option  starts  Vim  in Hebrew mode, i.e. 'hkmap' and
                   'rightleft' are set.  Otherwise an error message  is  given
                   and Vim aborts.

       -i {viminfo}
                   When  using  the  viminfo file is enabled, this option sets
                   the filename to use, instead of the  default  "~/.viminfo".
                   This can also be used to skip the use of the .viminfo file,
                   by giving the name "NONE".

       -L          Same as -r.

       -l          Lisp mode.  Sets the 'lisp' and 'showmatch' options on.

       -m          Modifying files is disabled.  Resets  the  'write'  option.
                   You  can still modify the buffer, but writing a file is not
                   possible.

       -M          Modifications not allowed.  The  'modifiable'  and  'write'
                   options  will be unset, so that changes are not allowed and
                   files can not be written.  Note that these options  can  be
                   set to enable making modifications.

       -N          No-compatible  mode.   Reset the 'compatible' option.  This
                   will make Vim behave a bit better, but less Vi  compatible,
                   even though a .vimrc file does not exist.

       -n          No  swap file will be used.  Recovery after a crash will be
                   impossible.  Handy if you want to edit a  file  on  a  very
                   slow  medium  (e.g.  floppy).   Can also be done with ":set
                   uc=0".  Can be undone with ":set uc=200".

       -nb         Become an editor server for NetBeans.   See  the  docs  for
                   details.

       -o[N]       Open N windows stacked.  When N is omitted, open one window
                   for each file.

       -O[N]       Open N windows side by side.  When N is omitted,  open  one
                   window for each file.

       -p[N]       Open N tab pages.  When N is omitted, open one tab page for
                   each file.

       -R          Read-only mode.  The 'readonly' option will  be  set.   You
                   can still edit the buffer, but will be prevented from acci-
                   dentally overwriting a file.  If you do want to overwrite a
                   file,  add  an  exclamation  mark  to the Ex command, as in
                   ":w!".  The -R option  also  implies  the  -n  option  (see
                   above).   The  'readonly'  option  can  be reset with ":set
                   noro".  See ":help 'readonly'".

       -r          List swap files, with  information  about  using  them  for
                   recovery.

       -r {file}   Recovery  mode.  The swap file is used to recover a crashed
                   editing session.  The swap file is a  file  with  the  same
                   filename as the text file with ".swp" appended.  See ":help
                   recovery".

       -s          Silent mode.  Only when started as "Ex" or  when  the  "-e"
                   option was given before the "-s" option.

       -s {scriptin}
                   The  script file {scriptin} is read.  The characters in the
                   file are interpreted as if you had typed  them.   The  same
                   can be done with the command ":source! {scriptin}".  If the
                   end of the file is reached before the editor exits, further
                   characters are read from the keyboard.

       -T {terminal}
                   Tells  Vim  the  name  of the terminal you are using.  Only
                   required when the automatic way doesn't work.  Should be  a
                   terminal  known  to Vim (builtin) or defined in the termcap
                   or terminfo file.

       -u {vimrc}  Use the commands in the file {vimrc}  for  initializations.
                   All  the  other  initializations  are skipped.  Use this to
                   edit a special kind of files.  It can also be used to  skip
                   all  initializations by giving the name "NONE".  See ":help
                   initialization" within vim for more details.

       -U {gvimrc} Use the commands in the file {gvimrc} for  GUI  initializa-
                   tions.   All the other GUI initializations are skipped.  It
                   can also be used to skip all GUI initializations by  giving
                   the  name "NONE".  See ":help gui-init" within vim for more
                   details.

       -V[N]       Verbose.  Give messages about which files are  sourced  and
                   for  reading and writing a viminfo file.  The optional num-
                   ber N is the value for 'verbose'.  Default is 10.

       -v          Start Vim in Vi mode, just like the executable  was  called
                   "vi".   This  only has effect when the executable is called
                   "ex".

       -w {scriptout}
                   All the characters that you type are recorded in  the  file
                   {scriptout},  until  you  exit  Vim.  This is useful if you
                   want to create a script file to be used with  "vim  -s"  or
                   ":source!".  If the {scriptout} file exists, characters are
                   appended.

       -W {scriptout}
                   Like -w, but an existing file is overwritten.

       -x          Use encryption when writing files.  Will prompt for a crypt
                   key.

       -X          Don't  connect to the X server.  Shortens startup time in a
                   terminal, but the window title and clipboard  will  not  be
                   used.

       -y          Start Vim in easy mode, just like the executable was called
                   "evim" or "eview".  Makes Vim behave like a  click-and-type
                   editor.

       -Z          Restricted  mode.   Works  like  the executable starts with
                   "r".

       --          Denotes the end of the options.  Arguments after this  will
                   be  handled  as  a  file  name.  This can be used to edit a
                   filename that starts with a '-'.

       --echo-wid  GTK GUI only: Echo the Window ID on stdout.

       --help      Give a help message and exit, just like "-h".

       --literal   Take file name arguments literally,  do  not  expand  wild-
                   cards.   This has no effect on Unix where the shell expands
                   wildcards.

       --noplugin  Skip loading plugins.  Implied by -u NONE.

       --remote    Connect to a Vim server and make it edit the files given in
                   the rest of the arguments.  If no server is found a warning
                   is given and the files are edited in the current Vim.

       --remote-expr {expr}
                   Connect to a Vim server, evaluate {expr} in  it  and  print
                   the result on stdout.

       --remote-send {keys}
                   Connect to a Vim server and send {keys} to it.

       --remote-silent
                   As  --remote,  but  without  the  warning when no server is
                   found.

       --remote-wait
                   As --remote, but Vim does not exit  until  the  files  have
                   been edited.

       --remote-wait-silent
                   As --remote-wait, but without the warning when no server is
                   found.

       --serverlist
                   List the names of all Vim servers that can be found.

       --servername {name}
                   Use {name} as the server name.  Used for the  current  Vim,
                   unless used with a --remote argument, then it's the name of
                   the server to connect to.

       --socketid {id}
                   GTK GUI only: Use the GtkPlug  mechanism  to  run  gvim  in
                   another window.

       --version   Print version information and exit.

ON-LINE HELP
       Type  ":help"  in Vim to get started.  Type ":help subject" to get help
       on a specific subject.  For example: ":help ZZ" to  get  help  for  the
       "ZZ"  command.   Use <Tab> and CTRL-D to complete subjects (":help cmd-
       line-completion").  Tags are present to jump from one place to  another
       (sort of hypertext links, see ":help").  All documentation files can be
       viewed in this way, for example ":help syntax.txt".

FILES
       /usr/local/lib/vim/doc/*.txt
                      The Vim documentation files.  Use ":help  doc-file-list"
                      to get the complete list.

       /usr/local/lib/vim/doc/tags
                      The  tags file used for finding information in the docu-
                      mentation files.

       /usr/local/lib/vim/syntax/syntax.vim
                      System wide syntax initializations.

       /usr/local/lib/vim/syntax/*.vim
                      Syntax files for various languages.

       /usr/local/lib/vim/vimrc
                      System wide Vim initializations.

       ~/.vimrc       Your personal Vim initializations.

       /usr/local/lib/vim/gvimrc
                      System wide gvim initializations.

       ~/.gvimrc      Your personal gvim initializations.

       /usr/local/lib/vim/optwin.vim
                      Script used for the ":options" command, a  nice  way  to
                      view and set options.

       /usr/local/lib/vim/menu.vim
                      System wide menu initializations for gvim.

       /usr/local/lib/vim/bugreport.vim
                      Script to generate a bug report.  See ":help bugs".

       /usr/local/lib/vim/filetype.vim
                      Script  to  detect  the type of a file by its name.  See
                      ":help 'filetype'".

       /usr/local/lib/vim/scripts.vim
                      Script to detect the type of a  file  by  its  contents.
                      See ":help 'filetype'".

       /usr/local/lib/vim/print/*.ps
                      Files used for PostScript printing.

       For recent info read the VIM home page:
       <URL:http://www.vim.org/>

SEE ALSO
       vimtutor(1)

AUTHOR
       Most of Vim was made by Bram Moolenaar, with a lot of help from others.
       See ":help credits" in Vim.
       Vim is based on Stevie, worked on by: Tim Thompson,  Tony  Andrews  and
       G.R.  (Fred) Walter.  Although hardly any of the original code remains.

BUGS
       Probably.  See ":help todo" for a list of known problems.

       Note that a number of things that may be regarded as bugs by some,  are
       in  fact  caused by a too-faithful reproduction of Vi's behaviour.  And
       if you think other things are bugs "because Vi  does  it  differently",
       you  should  take  a closer look at the vi_diff.txt file (or type :help
       vi_diff.txt when in Vim).  Also have a look  at  the  'compatible'  and
       'cpoptions' options.



                                  2006 Apr 11                           VIM(1)
In [15]:
man emacs
EMACS(1)                                                              EMACS(1)



NAME
       emacs - GNU project Emacs

SYNOPSIS
       emacs [ command-line switches ] [ files ...  ]

DESCRIPTION
       GNU  Emacs is a version of Emacs, written by the author of the original
       (PDP-10) Emacs, Richard Stallman.
       The primary documentation of GNU Emacs is  in  the  GNU  Emacs  Manual,
       which  you  can  read  using Info, either from Emacs or as a standalone
       program.  Please look there for complete and up-to-date  documentation.
       This  man  page  is  updated only when someone volunteers to do so; the
       Emacs maintainers' priority goal is to minimize the amount of time this
       man page takes away from other more useful projects.
       The  user functionality of GNU Emacs encompasses everything other Emacs
       editors do, and it is easily extensible since its editing commands  are
       written in Lisp.

       Emacs  has  an  extensive  interactive  help facility, but the facility
       assumes that you know how to  manipulate  Emacs  windows  and  buffers.
       CTRL-h or F1 enters the Help facility.  Help Tutorial (CTRL-h t) starts
       an interactive tutorial which can teach beginners the  fundamentals  of
       Emacs  in a few minutes.  Help Apropos (CTRL-h a) helps you find a com-
       mand given its functionality, Help Character  (CTRL-h  c)  describes  a
       given  character's  effect,  and  Help  Function (CTRL-h f) describes a
       given Lisp function specified by name.

       Emacs's Undo can undo several steps of modification to your buffers, so
       it is easy to recover from editing mistakes.

       GNU Emacs's many special packages handle mail reading (RMail) and send-
       ing (Mail), outline editing  (Outline),  compiling  (Compile),  running
       subshells  within Emacs windows (Shell), running a Lisp read-eval-print
       loop (Lisp-Interaction-Mode),  automated  psychotherapy  (Doctor),  and
       much more.

       There  is  an  extensive  reference  manual, but users of other Emacses
       should have little trouble adapting even without a copy.  Users new  to
       Emacs will be able to use basic features fairly rapidly by studying the
       tutorial and using the self-documentation features.

       Emacs Options

       The following options are of general interest:

       file    Edit file.

       +number Go to the line specified by  number  (do  not  insert  a  space
               between the "+" sign and the number).  This applies only to the
               next file specified.

       +line:column
               Go to the specified line and column

       -q      Do not load an init file.

       -no-site-file
               Do not load the site-wide startup file.

       -debug-init
               Enable Emacs Lisp debugger during the processing  of  the  user
               init  file  ~/.emacs.  This is useful for debugging problems in
               the init file.

       -u user Load user's init file.

       -t file Use specified file as the terminal instead of using  stdin/std-
               out.   This must be the first argument specified in the command
               line.

       -version
               Display Emacs version information and exit.

       The following options are lisp-oriented (these options are processed in
       the order encountered):

       -f function
               Execute the lisp function function.

       -l file Load the lisp code in the file file.

       -eval expr
               Evaluate the Lisp expression expr.

       The following options are useful when running Emacs as a batch editor:

       -batch  Edit  in  batch mode.  The editor will send messages to stderr.
               This option must be the first in the argument list.   You  must
               use -l and -f options to specify files to execute and functions
               to call.

       -kill   Exit Emacs while in batch mode.

       -L directory
               Add directory to the list of  directories  Emacs  searches  for
               Lisp files.

       Using Emacs with X

       Emacs  has been tailored to work well with the X window system.  If you
       run Emacs from under X windows, it will create its own X window to dis-
       play  in.   You  will probably want to start the editor as a background
       process so that you can continue using your original window.

       Emacs can be started with the following X switches:

       -name name
               Specifies the name which should  be  assigned  to  the  initial
               Emacs  window.  This controls looking up X resources as well as
               the window title.

       -title name
               Specifies the title for the initial X window.

       -r      Display the Emacs window in reverse video.

       -font font, -fn font
               Set the Emacs window's font to that  specified  by  font.   You
               will  find the various X fonts in the /usr/lib/X11/fonts direc-
               tory.  Note that Emacs will  only  accept  fixed  width  fonts.
               Under  the X11 Release 4 font-naming conventions, any font with
               the value "m" or "c" in the eleventh field of the font name  is
               a  fixed  width font.  Furthermore, fonts whose name are of the
               form widthxheight are generally fixed width,  as  is  the  font
               fixed.  See xlsfonts(1) for more information.

               When  you  specify  a  font, be sure to put a space between the
               switch and the font name.

       -bw pixels
               Set the Emacs window's border width to  the  number  of  pixels
               specified by pixels.  Defaults to one pixel on each side of the
               window.

       -ib pixels
               Set the window's internal border width to the number of  pixels
               specified  by pixels.  Defaults to one pixel of padding on each
               side of the window.


       --geometry geometry
               Set the Emacs window's width, height, and  position  as  speci-
               fied.   The geometry specification is in the standard X format;
               see X(1) for more information.  The width and height are speci-
               fied  in  characters;  the  default is 80 by 24.  See the Emacs
               manual, section "Options for Window  Size  and  Position",  for
               information on how window sizes interact with selecting or des-
               electing the tool bar and menu bar.


       -fg color
               On color displays, sets the color of the text.

               Use the command M-x list-colors-display for  a  list  of  valid
               color names.

       -bg color
               On color displays, sets the color of the window's background.

       -bd color
               On color displays, sets the color of the window's border.

       -cr color
               On  color displays, sets the color of the window's text cursor.

       -ms color
               On color displays, sets the color of the window's mouse cursor.

       -d displayname, -display displayname
               Create  the  Emacs  window on the display specified by display-
               name.  Must be the first option specified in the command  line.

       -nw     Tells  Emacs not to use its special interface to X.  If you use
               this switch when invoking Emacs from an xterm(1)  window,  dis-
               play is done in that window.

       You can set X default values for your Emacs windows in your .Xresources
       file (see xrdb(1)).  Use the following format:

              emacs.keyword:value

       where value specifies the default value of keyword.  Emacs lets you set
       default values for the following keywords:

       font (class Font)
               Sets the window's text font.

       reverseVideo (class ReverseVideo)
               If  reverseVideo's  value is set to on, the window will be dis-
               played in reverse video.

       bitmapIcon (class BitmapIcon)
               If bitmapIcon's value is set to on,  the  window  will  iconify
               into the "kitchen sink."

       borderWidth (class BorderWidth)
               Sets the window's border width in pixels.

       internalBorder (class BorderWidth)
               Sets the window's internal border width in pixels.

       foreground (class Foreground)
               For color displays, sets the window's text color.

       background (class Background)
               For color displays, sets the window's background color.

       borderColor (class BorderColor)
               For color displays, sets the color of the window's border.

       cursorColor (class Foreground)
               For color displays, sets the color of the window's text cursor.

       pointerColor (class Foreground)
               For color displays, sets the color of the window's  mouse  cur-
               sor.

       geometry (class Geometry)
               Sets the geometry of the Emacs window (as described above).

       title (class Title)
               Sets the title of the Emacs window.

       iconName (class Title)
               Sets the icon name for the Emacs window icon.

       If  you  try to set color values while using a black and white display,
       the window's characteristics will default as  follows:  the  foreground
       color  will be set to black, the background color will be set to white,
       the border color will be set to grey, and the text  and  mouse  cursors
       will be set to black.

       Using the Mouse

       The  following  lists  the  mouse  button bindings for the Emacs window
       under X11.


       MOUSE BUTTON        FUNCTION
       left                Set point.
       middle              Paste text.
       right               Cut text into X cut buffer.
       SHIFT-middle        Cut text into X cut buffer.
       SHIFT-right         Paste text.
       CTRL-middle         Cut text into X cut buffer and kill it.
       CTRL-right          Select this window, then split it into  two  windows.
                           Same as typing CTRL-x 2.
       CTRL-SHIFT-left     X buffer menu -- hold the buttons and keys down, wait
                           for menu to appear, select buffer, and release.  Move
                           mouse out of menu and release to cancel.
       CTRL-SHIFT-middle   X help menu -- pop up index card menu for Emacs help.
       CTRL-SHIFT-right    Select  window  with mouse, and delete all other win-
                           dows.  Same as typing CTRL-x 1.


MANUALS
       You can order printed copies of the GNU  Emacs  Manual  from  the  Free
       Software  Foundation, which develops GNU software.  See the file ORDERS
       for ordering information.
       Your local Emacs maintainer might also have copies available.  As  with
       all  software  and publications from FSF, everyone is permitted to make
       and distribute copies of the Emacs manual.  The TeX source to the  man-
       ual is also included in the Emacs source distribution.


FILES
       /usr/local/share/info  - files for the Info documentation browser.  The
       complete text of the Emacs reference manual is included in a convenient
       tree  structured  form.  Also includes the Emacs Lisp Reference Manual,
       useful to anyone wishing to write programs in the Emacs Lisp  extension
       language.

       /usr/local/share/emacs/$VERSION/lisp  -  Lisp source files and compiled
       files that define most editing commands.  Some  are  preloaded;  others
       are autoloaded from this directory when used.

       /usr/local/libexec/emacs/$VERSION/$ARCH  -  various  programs  that are
       used with GNU Emacs.

       /usr/local/share/emacs/$VERSION/etc - various files of information.

       /usr/local/share/emacs/$VERSION/etc/DOC.* - contains the  documentation
       strings  for  the  Lisp  primitives and preloaded Lisp functions of GNU
       Emacs.  They are stored here to reduce the size of Emacs proper.

       /usr/local/share/emacs/$VERSION/etc/SERVICE lists people offering vari-
       ous  services  to assist users of GNU Emacs, including education, trou-
       bleshooting, porting and customization.



BUGS
       There is a mailing list,  bug-gnu-emacs@gnu.org,  for  reporting  Emacs
       bugs and fixes.  But before reporting something as a bug, please try to
       be sure that it really is a bug, not a misunderstanding or a deliberate
       feature.   We ask you to read the section ``Reporting Emacs Bugs'' near
       the end of the reference manual (or Info system) for hints on  how  and
       when to report bugs.  Also, include the version number of the Emacs you
       are running in every bug report that you send in.

       Do not expect a personal answer  to  a  bug  report.   The  purpose  of
       reporting  bugs  is to get them fixed for everyone in the next release,
       if possible.  For personal assistance, look in the  SERVICE  file  (see
       above) for a list of people who offer it.

       Please  do not send anything but bug reports to this mailing list.  For
       more  information   about   Emacs   mailing   lists,   see   the   file
       /usr/local/emacs/etc/MAILINGLISTS.   Bugs  tend actually to be fixed if
       they can be isolated, so it is in your interest to report them in  such
       a way that they can be easily reproduced.

UNRESTRICTIONS
       Emacs  is free; anyone may redistribute copies of Emacs to anyone under
       the terms stated in the Emacs General Public License, a copy  of  which
       accompanies  each copy of Emacs and which also appears in the reference
       manual.

       Copies of Emacs may sometimes be received packaged  with  distributions
       of  Unix  systems, but it is never included in the scope of any license
       covering those systems.  Such inclusion violates  the  terms  on  which
       distribution is permitted.  In fact, the primary purpose of the General
       Public License is to prohibit anyone from attaching any other  restric-
       tions to redistribution of Emacs.

       Richard  Stallman encourages you to improve and extend Emacs, and urges
       that you contribute your extensions to the GNU library.  Eventually GNU
       (Gnu's  Not  Unix)  will  be a complete replacement for Unix.  Everyone
       will be free to use, copy, study and change the GNU system.

SEE ALSO
       emacsclient(1), etags(1), X(1), xlsfonts(1), xterm(1), xrdb(1)

AUTHORS
       Emacs was written by Richard Stallman and the Free Software Foundation.
       Joachim Martillo and Robert Krawitz added the X features.

COPYING
       Copyright (C) 1995, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
             2006, 2007 Free Software Foundation, Inc.

       Permission  is  granted  to make and distribute verbatim copies of this
       document provided the copyright notice and this permission  notice  are
       preserved on all copies.

       Permission  is granted to copy and distribute modified versions of this
       document under the conditions for verbatim copying, provided  that  the
       entire  resulting derived work is distributed under the terms of a per-
       mission notice identical to this one.

       Permission is granted to copy and distribute translations of this docu-
       ment  into  another  language,  under the above conditions for modified
       versions, except that this permission notice may be stated in a  trans-
       lation approved by the Free Software Foundation.




GNU Emacs 22.1                   2007 April 13                        EMACS(1)
In [16]:
man nano
NANO(1)                                                                NANO(1)



NAME
       nano - Nano's ANOther editor, an enhanced free Pico clone


SYNOPSIS
       nano [options] [[+line[,column]] file]...


DESCRIPTION
       nano  is  a  small and friendly editor.  It copies the look and feel of
       Pico, but is free software, and implements several features  that  Pico
       lacks,  such as: opening multiple files, scrolling per line, undo/redo,
       syntax coloring, line numbering, and soft-wrapping overlong lines.

       When giving a filename on the command line, the cursor can be put on  a
       specific line by adding the line number with a plus sign (+) before the
       filename, and even in a specific column by adding it with a comma.

       As a special case: if instead of a filename a dash (-) is  given,  nano
       will read data from standard input.


EDITING
       Entering  text  and  moving around in a file is straightforward: typing
       the letters and using the normal cursor movement  keys.   Commands  are
       entered by using the Control (^) and the Alt or Meta (M-) keys.  Typing
       ^K deletes the current line and puts it in the cutbuffer.   Consecutive
       ^Ks  will  put all deleted lines together in the cutbuffer.  Any cursor
       movement or executing any other command will cause the next ^K to over-
       write  the cutbuffer.  A ^U will paste the current contents of the cut-
       buffer at the current cursor position.

       When a more precise piece of text needs to be cut or  copied,  one  can
       mark  its  start  with  ^6, move the cursor to its end (the marked text
       will be highlighted), and then use ^K to cut it, or M-6 to copy  it  to
       the cutbuffer.  One can also save the marked text to a file with ^O, or
       spell check it with ^T.

       On some terminals, text can be selected  also  by  holding  down  Shift
       while  using the arrow keys.  Holding down the Ctrl or Alt key too will
       increase the stride.  Any cursor movement without Shift being held will
       cancel such a selection.

       The two lines at the bottom of the screen show some important commands;
       the built-in help (^G) lists all the available ones.  The  default  key
       bindings can be changed via a nanorc file -- see nanorc(5).


OPTIONS
       -A, --smarthome
              Make the Home key smarter.  When Home is pressed anywhere but at
              the very beginning of non-whitespace characters on a  line,  the
              cursor  will  jump  to  that beginning (either forwards or back-
              wards).  If the cursor is already at that position, it will jump
              to the true beginning of the line.

       -B, --backup
              When  saving  a  file, back up the previous version of it, using
              the current filename suffixed with a tilde (~).

       -C directory, --backupdir=directory
              Make and keep not just one backup file,  but  make  and  keep  a
              uniquely numbered one every time a file is saved -- when backups
              are enabled (-B).  The uniquely numbered files are stored in the
              specified directory.

       -D, --boldtext
              Use bold text instead of reverse video text.

       -E, --tabstospaces
              Convert typed tabs to spaces.

       -F, --multibuffer
              Read a file into a new buffer by default.

       -G, --locking
              Use vim-style file locking when editing files.

       -H, --historylog
              Save the last hundred search strings and replacement strings and
              executed commands, so they can be easily reused  in  later  ses-
              sions.

       -I, --ignorercfiles
              Don't look at the system's nanorc nor at the user's nanorc.

       -K, --rebindkeypad
              Interpret  the  numeric  keypad keys so that they all work prop-
              erly.  You should only need to use this option if they don't, as
              mouse support won't work properly with this option enabled.

       -L, --nonewlines
              Don't  automatically add a newline when a file does not end with
              one.

       -M, --trimblanks
              Snip trailing whitespace from the wrapped  line  when  automatic
              hard-wrapping occurs or when text is justified.

       -N, --noconvert
              Disable automatic conversion of files from DOS/Mac format.

       -O, --morespace
              Use the blank line below the title bar as extra editing space.

       -P, --positionlog
              For the 200 most recent files, log the last position of the cur-
              sor, and place it at that position again upon reopening  such  a
              file.

       -Q "regex", --quotestr="regex"
              Set  the  regular  expression for matching the quoting part of a
              line.  This is used  when  justifying.   The  default  value  is
              "^([ \t]*([#:>|}]|//))+".   Note  that  \t  stands for an actual
              Tab.

       -R, --restricted
              Restricted mode: don't read or write to any file  not  specified
              on  the  command  line.  This means: don't read or write history
              files; don't allow suspending; don't allow spell checking; don't
              allow  a  file to be appended to, prepended to, or saved under a
              different name if it already has  one;  and  don't  make  backup
              files.   Restricted  mode can also be activated by invoking nano
              with any name beginning with 'r' (e.g. "rnano").

       -S, --smooth
              Use smooth scrolling: text will scroll line-by-line, instead  of
              the usual chunk-by-chunk behavior.

       -T number, --tabsize=number
              Set  the  size (width) of a tab to number columns.  The value of
              number must be greater than 0.  The default value is 8.

       -U, --quickblank
              Do quick status-bar blanking: status-bar messages will disappear
              after  1  keystroke  instead of 25.  Note that option -c (--con-
              stantshow) overrides this.

       -V, --version
              Show the current version number and exit.

       -W, --wordbounds
              Detect word boundaries differently by treating punctuation char-
              acters as part of a word.

       -X "characters", --wordchars="characters"
              Specify  which other characters (besides the normal alphanumeric
              ones) should be considered as part of a  word.   This  overrides
              option -W (--wordbounds).

       -Y name, --syntax=name
              Specify  the  name  of the syntax highlighting to use from among
              the ones defined in the nanorc files.

       -Z, --zap
              Let an unmodified Backspace or Delete erase  the  marked  region
              (instead  of  a single character, and without affecting the cut-
              buffer).

       -a, --atblanks
              When doing soft line wrapping, wrap lines at whitespace  instead
              of always at the edge of the screen.

       -c, --constantshow
              Constantly  show  the  cursor  position on the status bar.  Note
              that this overrides option -U (--quickblank).

       -d, --rebinddelete
              Interpret the Delete key differently so that both Backspace  and
              Delete  work  properly.  You should only need to use this option
              if Backspace acts like Delete on your system.

       -g, --showcursor
              Make the cursor visible in the file browser (putting it  on  the
              highlighted  item)  and  in the help viewer.  Useful for braille
              users and people with poor vision.

       -h, --help
              Show a summary of the available command-line options and exit.

       -i, --autoindent
              Automatically indent a newly created line to the same number  of
              tabs  and/or spaces as the previous line (or as the next line if
              the previous line is the beginning of a paragraph).

       -k, --cutfromcursor
              Make the 'Cut Text' command (normally ^K) cut from  the  current
              cursor  position  to the end of the line, instead of cutting the
              entire line.

       -l, --linenumbers
              Display line numbers to the left of the text area.

       -m, --mouse
              Enable mouse  support,  if  available  for  your  system.   When
              enabled,  mouse  clicks can be used to place the cursor, set the
              mark (with a double click), and execute  shortcuts.   The  mouse
              will work in the X Window System, and on the console when gpm is
              running.  Text can still be selected through dragging by holding
              down the Shift key.

       -n, --noread
              Treat  any  name  given on the command line as a new file.  This
              allows nano to write to named pipes: it will start with a  blank
              buffer,  and  will  write  to  the  pipe when the user saves the
              "file".  This way nano can be used as an editor  in  combination
              with  for instance gpg without having to write sensitive data to
              disk first.

       -o directory, --operatingdir=directory
              Set the operating directory.  This makes nano set  up  something
              similar to a chroot.

       -p, --preserve
              Preserve  the XON and XOFF sequences (^Q and ^S) so they will be
              caught by the terminal.

       -q, --quiet
              Obsolete option.  Recognized but ignored.

       -r number, --fill=number
              Hard-wrap lines at column number.  If this value is 0  or  less,
              wrapping  will occur at the width of the screen less number col-
              umns, allowing the wrap point to vary along with  the  width  of
              the  screen  if the screen is resized.  The default value is -8.
              This option conflicts with -w (--nowrap) -- the last  one  given
              takes effect.

       -s program, --speller=program
              Use this alternative spell checker command.

       -t, --tempfile
              Save  a changed buffer without prompting (when exiting with ^X).

       -u, --unix
              Save a file by default in Unix format.   This  overrides  nano's
              default  behavior  of  saving  a file in the format that it had.
              (This option has no effect when you also use --noconvert.)

       -v, --view
              Just view the file and disallow editing: read-only  mode.   This
              mode  allows  the  user  to  open  also other files for viewing,
              unless --restricted is given too.

       -w, --nowrap
              Disable the hard-wrapping of long lines.  This option  conflicts
              with -r (--fill) -- the last one given takes effect.

       -x, --nohelp
              Don't show the two help lines at the bottom of the screen.

       -y, --afterends
              Make Ctrl+Right stop at word ends instead of beginnings.

       -z, --suspend
              Enable the suspend ability.

       -$, --softwrap
              Enable  'soft wrapping'.  This will make nano attempt to display
              the entire contents of any line, even if it is longer  than  the
              screen  width,  by  continuing  it  over  multiple screen lines.
              Since '$' normally refers to a variable in the Unix  shell,  you
              should  specify  this option last when using other options (e.g.
              'nano -wS$') or pass it separately (e.g. 'nano -wS -$').

       -b, -e, -f, -j
              Ignored, for compatibility with Pico.


TOGGLES
       Several of the above options can be switched on and off also while nano
       is  running.  For example, M-L toggles the hard-wrapping of long lines,
       M-$ toggles soft-wrapping, M-# toggles line numbers,  M-M  toggles  the
       mouse, M-I auto-indentation, and M-X the help lines.  See at the end of
       the ^G help text for a complete list.


INITIALIZATION FILE
       nano will read two configuration files: first the system's  nanorc  (if
       it exists), and then the user's nanorc (if it exists), either ~/.nanorc
       or $XDG_CONFIG_HOME/nano/nanorc or ~/.config/nano/nanorc, whichever  is
       encountered  first.  See nanorc(5) for more information on the possible
       contents of those files.


NOTES
       If no alternative spell checker command is  specified  on  the  command
       line nor in one of the nanorc files, nano will check the SPELL environ-
       ment variable for one.

       In some cases nano will try to dump the buffer into an emergency  file.
       This  will  happen  mainly if nano receives a SIGHUP or SIGTERM or runs
       out of memory.  It will write the buffer into a file named nano.save if
       the  buffer didn't have a name already, or will add a ".save" suffix to
       the current filename.  If an emergency  file  with  that  name  already
       exists  in  the  current  directory,  it will add ".save" plus a number
       (e.g. ".save.1") to the current filename in order to  make  it  unique.
       In  multibuffer  mode,  nano  will  write all the open buffers to their
       respective emergency files.


BUGS
       Justifications (^J) are not yet covered by the general undo system.  So
       after  a  justification  that  is not immediately undone, earlier edits
       cannot be undone any more.  The workaround is, of course, to exit with-
       out saving.

       The recording and playback of keyboard macros works correctly only on a
       terminal emulator, not on a Linux console (VT), because the latter does
       not by default distinguish modified from unmodified arrow keys.

       Please report any other bugs that you encounter via:
       https://savannah.gnu.org/bugs/?group=nano.

       When nano crashes, it will save any modified buffers to emergency .save
       files.  If you are able to reproduce the crash and you want  to  get  a
       backtrace, define the environment variable NANO_NOCATCH.


HOMEPAGE
       https://nano-editor.org/


SEE ALSO
       nanorc(5)

       /usr/share/doc/nano/ (or equivalent on your system)


AUTHOR
       Chris  Allegretta  and  others  (see  the  files AUTHORS and THANKS for
       details).  This manual page was originally written by Jordi Mallach for
       the Debian system (but may be used by others).



November 2018                     version 3.2                          NANO(1)

Exercise

Let's create some data using echo or any of the editors we have seen today.

For instance, a four word file which the following information,

Name Code Age Career

Let's try to send this information to a file usr.txt were you must use your Andes email user instead of usr

Note Use spaces as separators!!

How can we download this data form Binder?

Send the file to j.sevillam@uniandes.edu.co.

(This will be counted as the assistence to the class for today.)

Why to do this?

This is done for you to see an example where python can be extremelly usefull (We are very close to start python)

Let see just a few examples of its use as a motivation before working directly with it.

Next class

We are going to keep exploring the shell, but a little bit more complex, we'll see commands such as

  • grep
  • awk

And we will learn how to write some basic scripts.

Next, we will start talking about python

Remember

For the next class, you should have seen the videos 1 and 2!!

During the day, the first assignment will be uploaded. (You will recieve it via Email)