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

Subroutine , Subroutine :   A subroutine  is a type of subprogram, a pi...

Subroutine :   A subroutine  is a type of subprogram, a piece of code within a larger program that performs a specific task and is relatively independent of the remaining code.

#, #queswhat computers can do tion..

#queswhat computers can do tion..

Respiratory system, 100 animals and their respiratory organs

100 animals and their respiratory organs

Encoder, What is an encoder? Draw the logic circuit of Decimal to BCD encod...

What is an encoder? Draw the logic circuit of Decimal to BCD encoder and explain its working.?

Algorithm and flow chart, to find the sum and average of five input number

to find the sum and average of five input number

Algorithms and flowcharts, 1. Write an algorithm and draw a flowchart to ac...

1. Write an algorithm and draw a flowchart to accept the names and gross salary of 5000 employees and to generate the net pay. If the gross salary is greater than N 50,000 declare

Processor, Processor: Processor plays major role in a computer. One sh...

Processor: Processor plays major role in a computer. One should carefully decide about the type of processor and its speed before making a choice. Currently Core 2 Duo process

A* search-artificial intelligence, A* Search-Artificial intelligence:  ...

A* Search-Artificial intelligence:   A* search combines the best parts of uniform cost search that  called the fact that it's optimal and complete, and the best parts of gre

Sequential reading in fcb files, Earlier than anything we must describe the...

Earlier than anything we must describe the file transfer area or DTA. With the intention of sequentially read we use the 14H function of the 21Hinterruption.The register to be read

Cpu, what is cpu

what is cpu

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