A telephone directory, called teledir. txt, maintains records in the form name: number where number is of the form nnn-nnn- for example; Chelsey: 480-727-1007
Devise a shell script that accepts one or two arguments that could be:

the name or number. If it exists in the directory, then the line should be displayed.
both. The entry is displayed if it exists and is added if it doesn’t exist in the file.
You can follow the steps below (not the only way):

Assign the pathname to the file teledir. txt to a variable, say, TELEDIR. For example, if it is in your home directory, you’ll need to assign $HOME/teledir. txt to the variable TELEDIR
Check that one or two arguments are supplied using $# and the case…esac construct.
If one or two arguments are supplied, do nothing
otherwise, Indicate that the usage must be in the form scriptname [name number], then exit
Using the $# and the case…esac construct,
If one argument is supplied,
If it starts with a digit, search it in the file. If it doesn’t exist, echo that "Number doesn’t exist"
If it starts with a letter (lower or uppercase), search it in the file. If it doesn’t exist, echo that "Name doesn’t exist"
If two arguments are supplied, set the search_pattern to be "name: number", and search it in the file.
If it is not found, echo "Adding entry", and append to the file/variable.
Otherwise, echo that "Entry exists"

What are compression artifacts? 1) visible defects in the picture caused by the nature of the compression algorithm. 2) numbers that tell a web server how much to compress a picture for faster transmission. 3) invisible defects in the picture preserved by lossless compression. 4) numbers that tell a photo editing program how much to compress a picture for faster transmission.

We as humans write math expression in infix notation, e.g. 5 + 2 (the operators are written in-between the operands). in a computer’s language, however, it is preferred to have the operators on the right side of the operands, i.e. 5 2 +. for more complex expressions that include parenthesis and multiple operators, a compiler has to convert the expression into postfix first and then evaluate the resulting postfix.write a program that takes an “infix” expression as input, uses stacks to convert it into postfix expression, and finally evaluates it. it must support the following operations: + - / * ^ % (example infix expression: (7 - 3) / (2 + 2)postfix expression: 7 3 - 2 2 + /result: 1guidelines: 1. you will need to use stacks in three placesa. one for the parenthesis check [char stack]b. one during infix to postfix [char stack]c. one during evaluation [int stack]for a and b above, you can use same array and same push, pop method as both ofthem are char. but for evaluation you have int stack and you might consider to createanother push pop method to handle it. maybe push_int, pop_int, etc. or find otherstrategy to utilize existing push pop method2. you can create a function for obtaining operator priority. that function should take anoperator as input and return its priority as an integer. this function will you a lot andreduce repeated code3. during evaluation you will need to convert char into integer. example for single digit: char c = '5'; int x = c - '0';

What is the best assassins creed game?