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0x03-shell_variables_expansions

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Project

0x03. Shell, init files, variables and expansions

Table of Contents

Author Details

Project Description

  • Allowed editors: vi, vim, emacs
  • All your scripts will be tested on Ubuntu 20.04 LTS
  • All your scripts should be exactly two lines long ($ wc -l file should print 2)
  • All your files should end with a new line (why?)
  • The first line of all your files should be exactly #!/bin/bash
  • A README.md file, at the root of the folder of the project, describing what each script is doing
  • You are not allowed to use &&, || or ;
  • You are not allowed to use bc, sed or awk
  • All your files must be executable
  • Read your /etc/profile, /etc/inputrc and ~/.bashrc files.
  • Look at some files in the /etc/profile.d directory.

Tasks

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0.

  • Create a script that creates an alias.
    • Name: ls
    • Value: rm *



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 0-alias

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1. Hello you

  • Create a script that prints hello user, where user is the current Linux user.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 1-hello_you

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2. The path to success is to take massive, determined action

  • Add /action to the PATH. /action should be the last directory the shell looks into when looking for a program.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 2-path

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3. If the path be beautiful, let us not ask where it leads

  • Create a script that counts the number of directories in the PATH.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 3-paths

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4. Global variables

  • Create a script that lists environment variables.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 4-global_variables

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5. Local variables

  • Create a script that lists all local variables and environment variables, and functions.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 5-local_variables

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6. Local variable

  • Create a script that creates a new local variable.
    • Name: BEST
    • Value: School



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 6-create_local_variable

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7. Global variable

  • Create a script that creates a new global variable.
    • Name: BEST
    • Value: School



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 7-create_global_variable

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8. Every addition to true knowledge is an addition to human power

  • Write a script that prints the result of the addition of 128 with the value stored in the environment variable TRUEKNOWLEDGE, followed by a new line.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 8-true_knowledge

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9. Divide and rule

  • Write a script that prints the result of POWER divided by DIVIDE, followed by a new line.
    • POWER and DIVIDE are environment variables



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 9-divide_and_rule

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10. Love is anterior to life, posterior to death, initial of creation, and the exponent of breath

  • Write a script that displays the result of BREATH to the power LOVE
    • BREATH and LOVE are environment variables
    • The script should display the result, followed by a new line



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 10-love_exponent_breath

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11. There are 10 types of people in the world -- Those who understand binary, and those who don't

  • Write a script that converts a number from base 2 to base 10.
    • The number in base 2 is stored in the environment variable BINARY
    • The script should display the number in base 10, followed by a new line



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 11-binary_to_decimal

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12. Combination

  • Create a script that prints all possible combinations of two letters, except oo.
    • Letters are lower cases, from a to z
    • One combination per line
    • The output should be alpha ordered, starting with aa
    • Do not print oo
    • Your script file should contain maximum 64 characters



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 12-combinations

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13. Floats

  • Write a script that prints a number with two decimal places, followed by a new line.
    • The number will be stored in the environment variable NUM.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 13-print_float

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14. Decimal to Hexadecimal

  • Write a script that prints a number with two decimal places, followed by a new line.
  • The number will be stored in the environment variable NUM.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 100-decimal_to_hexadecimal

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15. Everyone is a proponent of strong encryption

  • Write a script that encodes and decodes text using the rot13 encryption. Assume ASCII.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 101-rot13

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16. The eggs of the brood need to be an odd number

  • Write a script that prints every other line from the input, starting with the first line.



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 102-odd

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17. I'm an instant star. Just add water and stir.

  • Write a shell script that adds the two numbers stored in the environment variables WATER and STIR and prints the result.
    • WATER is in base water
    • STIR is in base stir.
    • The result should be in base bestchol



  • Repo
    • GitHub repository: alx-system_engineering-devops
    • Directory: 0x03-shell_variables_expansions
    • File: 103-water_and_stir



Dean Robin Otsyeno - [email protected]