This assignment focuses on using regular expression and related commands such a grep. A set of files are needed for this assignment are available in hw6.zip in the homepage.

wget anassbelcaid.github.io/GiIA24/homeworks/06_shell_scripting/hw6.zip
unzip hw6.zip

Warm-up : Shell commands with grep

The following are warm-up exercises to get some practice with regular expressin and grep -E. For these exercises you’ll be searching from a file called names.txt tat contains both single-word usernames as well as full names. You may assume the file contains one name per line. Write your commands on the indicates lines in the task1.sh file in the hw6 folder.

Problem 1

Write the command that finds all usernames from names.txt that contain at least one numeric character.

Problem 2

Write the command that finds all usernames from names.txt that are exactly 4 characters long and consist only of alphabetic characters.

Problem 3

Write the command that finds all first and last names from names.txt. A name is an uppercase letter followed by one or more lowercase letters and first and last names are separated by a single space.

Your command should not matches with names that contain a middle name or initials.

Task 2: Bash shell commands with grep

After the few weeks at ENSA, management has discovered that we need to start actually selling products to stay in business. You’ll be helping develop regular expressions to help in customer account creation and billing. For each item below, determine a single bash shell statement that will perform the operations(s) requested. Write your commands on the indicated lines in the task2.sh file in hw6 folder.

Email Validation

As part of account creation, customer must provide a valid email address. Write a command that print out all valid email addresses from emails.txt. For the purposes of this assignment, we will use as simplified version of valid email address is defined as follows:

  1. Between 1 and 16 lowercase letters, uppercase letters, or digits.
  2. An @ symbol
  3. A domain (e.g. gmail) that consists of any number of lowercase letters.
  4. a period .

  5. A tld (top level domain, e.g. .com) that consists of 2 or more lowercase letters.

    You may assure emails.txt contains one email per line.

Password Validation

Customers also must choose a strong password when creating an account. Write a command that prints out all valid passwords in the file password.txt. A valid password at ENSA is defined as follows:

  • Must be at least 8 characters long.
  • Must contain at lest one uppercase character.
  • Must contain at least one lowercase character.
  • Must contain at lest one digit.

You mas assume that password.txt contains one password per line

Credit Card validation

In to process payment for orders, ENSA needs to validate credit cards entered on the site. Since we are a small company. we will only be accepting Visa and MasterCard. Write a command that identifies all well-formatted credit carsd in a file called cards.txt that ENSA accepts. The format of these cards are as follows

  • Master Card
    • Begins with a 5
    • Exactly 16 digits long, grouped into sets of 4 separated by a space.
  • Visa:
    • Beings with a 4
    • Between 13 and 16 digits long, grouped into a sets of 4 (last may be shorter) separated by a space separated by a space

Genetic data

ENSA has decided to enter the biotech space and process genomic data.

For these problems, you will need to process DNA from the file dna.txt. Data is printed in the file in pairs of lines. The first lien in the pair is the name of the DNA sequence and the second line is the DNA sequence itself. The following provides you with some context for the task, but an understanding of DNA is not required for this assignment.

DNA consists of long chains of chemical compounds called nucleotides. Four nucleotides are present in DNA: Adenine (A), Cytosine (C), Guanine (G), and Thymine (T). Certain regions of the DNA are called genes. Most genes encode instructions for building proteins (they’re called “protein-coding” genes). These proteins are responsible for carrying out most of the life processes of the organism. Nucleotides in a gene are organized into codons. Codons are groups of three nucleotides and are written as the first letters of their nucleotides (e.g., TAC or GGA). Each codon uniquely encodes a single amino acid, a building block of proteins.

Problem 7

Print all the of the DNA sequences in the file (all of the non-names).

Problem 8

Print all of the names of DNA sequences in the file.

Problem 9

Print the full DNA sequence that contain the word CAT preceded by the name of the sequence.

Problem 10

Print all of the DNA sequences that start and end with the same codon (three letters). For this case do not worry about matching start and end codons that don’t have the same casing as each other.

Problem 11

Print all valid genes in the file. That is, all of DNA sequences that can be divided into codons(i.e A sequence of A, C, G, and T’s and a has a length of 3).

Problem 12

Protein-coding genes are gens that begin with ATG end with one of TTA, TAG, or TGA and at least 5 codons long.

Print all the protein-encoding gens in the file.