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

Fhtjhnkjfdum, ryby db fgrh herbgh buyh hehg gvo hb bbithbs bgshbshdgbh bu...

ryby db fgrh herbgh buyh hehg gvo hb bbithbs bgshbshdgbh bubfvhb bs v h hjjg jdk jnmnv j

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

What are the goals of wap architecture, Question 1 Explain the naming conv...

Question 1 Explain the naming conventions of functions in WML scripts and also explain characteristics of functions in WML Question 2 What is WML input field? Explain WML

Computational physiology, Estimate the mean deflection of the QRS complex i...

Estimate the mean deflection of the QRS complex in each of the six standard leads (I, II, III, aVR, aVL, aVF) in Figure 1 and then estimate the mean heart vector for the normal hea

Why is the random class in the .net framework not suitable, QUESTION (a...

QUESTION (a) (i) Why is the Random class in the .NET framework not suitable for generating random bytes for cryptography purposes? (ii) Mention two characteristics required

Printers, Printers: Printers: Printers exist in a variety of forms:  ...

Printers: Printers: Printers exist in a variety of forms:  Line Printers: These have been widely used for many years in large computer installations. They are design

Uniform path cost search-artificial intelligence, Uniform Path Cost Search-...

Uniform Path Cost Search-Artificial intelligence A breadth first search will search the solution with the shortest path length from the first state to the goal state. Though, t

Programming languages, difference between a compiler and a translator

difference between a compiler and a translator

Explain FDM : Frequency Division Multiplexing, Frequency Division Multiplex...

Frequency Division Multiplexing : FDM is an analog technique that is applied when he bandwidth of link is greater than the combined bandwidth of the signals to be transmitted. a

Management information systems, how to introduce information system an in o...

how to introduce information system an in organization

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