User Account

All Pages

Unix Shell, Basic Computer Science

Assignment Help:
Write a shell script, change-lines, which will substitute a string for a replacement string for each occurance of the string in files specified.
The original file will be saved, with the same filename with the .keep extension unless the -n option is present.

You may use a temporary file for this script.

Remember the search string and or the replacement string can have special characters in them, so you must use proper quoting techniques.

The script will use following options:


the option -s "string" for the search strings
the option -r "string" for the replacement string
the -n option to prevent a backup file from being created
the -h option to print a usage statement and exit
The script will exit with an error status and print an error message:
if the -s option is not present.
if the -r option is not present.
if the string is not specified with the -s option
if the string is not specified with the -r option
if there are any other options specified
if there are no input files specified
if the input file cannot be read by the current process
if the input file cannot be written by the current process
if you cannot create the backup file.
Here is the usage statement for the script:
change-lines [-n] -s search string -r replace string files ...
-n do not backup the original file
-s search string the search for this string
-r replace string replace the search string with this string
-h print this message

Related Discussions:- Unix Shell

C++, whats the out put of int main(){ int n=310; funcone(n); functwo(&n); ...

whats the out put of int main(){ int n=310; funcone(n); functwo(&n); cout return 0; } void funcone(intn) n=240; } void func two(intn*) { n=120; }

Cpu modes of operation, fully detailed of cpu modes of operation

fully detailed of cpu modes of operation

Project, how to set up the location (e.g. plaza, hall of fame, lecture thea...

how to set up the location (e.g. plaza, hall of fame, lecture theater or etc.) and services that will be used during the exhibition; devices needed; and finally produced a compreh

Computer Networking and configuaration, Ask queYou are hired as a Chief Tec...

Ask queYou are hired as a Chief Technology Officer (CTO) of a startup company, which has two branches; one Los Angeles and one in San Francisco. The company hired employees to begi

Definition of procedure, A procedure is a compilation of instructions to wh...

A procedure is a compilation of instructions to which we can express the flow of our program, and once the execution of these instructions is over power is given back to the next l

First generation of computers, THE FIRST GENERATION (1949-1955) ...

THE FIRST GENERATION (1949-1955) The computers in this generation have the following characteristics:     Physically large in size     Inflexible in operations

Computer architecture, speed up factor for superscalar architecture

speed up factor for superscalar architecture

Cg, function of electrostatic plotter

function of electrostatic plotter

Historical background of computers, Historical Background The br...

Historical Background The brief history of the growth of computers is given below: Abacus:   It was the first mechanical device developed approximately 3,000 year

Explain the concept of a transition graph, Question 1 Define the concept o...

Question 1 Define the concept of equivalence relation. Give atleast two examples of equivalence relation Question 2 Prove that a graph G is connected if and only if it has a

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd