The Command Line

Purpose

The purpose of this presentation is to give a quick introduction to the command line computing environment.

Objectives

Be proficient in navigation between directories in the command line environment.
Understand basic shell programming.
Be able to write a for loop to complete a repetitive task.

You're going to need Unix

(there is a Windows 10 subsystem for linux)

Installing Linux (Ubuntu distribution) on Windows

What is the command line?

Basic parts

Syntax

command argument1 argument2 argument3 ... <press enter>
output

[EyeMac: ~]echo charlie bit me!
charlie bit me!
[EyeMac: ~]

[EyeMac: ~]say -v Zarvox brains are amazing

Getting Help: man

ECHO(1)                   BSD General Commands Manual                  ECHO(1)

NAME
     echo -- write arguments to the standard output

SYNOPSIS
     echo [-n] [string ...]

DESCRIPTION
     The echo utility writes any specified operands, separated by single blank
     (` ') characters and followed by a newline (`\n') character, to the stan-
     dard output.

     The following option is available:

     -n    Do not print the trailing newline character.  This may also be
           achieved by appending `\c' to the end of the string, as is done by
           iBCS2 compatible systems.  Note that this option as well as the
           effect of `\c' are implementation-defined in IEEE Std 1003.1-2001
           (``POSIX.1'') as amended by Cor. 1-2002.  Applications aiming for
           maximum portability are strongly encouraged to use printf(1) to
           suppress the newline character.

     Some shells may provide a builtin echo command which is similar or iden-
     tical to this utility.  Most notably, the builtin echo in sh(1) does not
     accept the -n option.  Consult the builtin(1) manual page.

EXIT STATUS
     The echo utility exits 0 on success, and >0 if an error occurs.

SEE ALSO
     builtin(1), csh(1), printf(1), sh(1)

STANDARDS
     The echo utility conforms to IEEE Std 1003.1-2001 (``POSIX.1'') as
     amended by Cor. 1-2002.

BSD                             April 12, 2003                             BSD
(END)

[EyeMac: ~]man echo

Useful commands

[EyeMac: ~]pwd
/Users/ben88

[EyeMac: ~]ls
@update.afni.binaries     Library                   bin
Applications              Movies                    build
Box                       Music                     get-pip.py
Desktop                   OneDrive - BYU Office 365 logfiles
Documents                 Pictures                  matlab
Downloads                 Public                    research_bin
Dropbox                   abin                      rubygems-2.7.5

[EyeMac: ~]cd Documents/
[EyeMac: Documents]pwd
/Users/ben88/Documents

[EyeMac: ~]mkdir myDirectory
[EyeMac: ~]ls
@update.afni.binaries     Movies                    get-pip.py
Applications              Music                     logfiles
Box                       OneDrive - BYU Office 365 matlab
Desktop                   Pictures                  myDirectory
Documents                 Public                    research_bin
Downloads                 abin                      rubygems-2.7.5
Dropbox                   bin
Library                   build

The For Loop

Some times you have to carryout a task that is repetitive, with a slight tweak for each iteration. The for loop is great for this.

for i in {<list of variables>}; do
	<commands>
done

for i in { 1 2 3 4 5 6 7 8 9 10 }; do
	touch subject_${i}.txt
done

[EyeMac: ~]ls
subject_1.txt
subject_2.txt
subject_3.txt
..
subject_10.txt

Next time

Complete the command line tutorial by Ubuntu.
Write and send me your working for loop.