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

Advantages of computerized record-keeping, Advantages of Computerized Reco...

Advantages of Computerized Record-keeping Less manpower is required for upkeep.  Recording, storing, and retrieving are all much faster: easier and with little practice

Define server clustering, Question 1 Discuss the impacts of disaster faced...

Question 1 Discuss the impacts of disaster faced by the organization Question 2 Explains the steps involved in disaster recovery planning Question 3 What do you mean by

Explain fdma and tdma concepts, Question 1 Explain Wireless Protocol Requi...

Question 1 Explain Wireless Protocol Requirements and also explain in brief medium access control protocol Question 2 Explain FDMA and TDMA concepts Question 3 Exp

Theory of computation, I define a restricted form of TMs M as follows. Give...

I define a restricted form of TMs M as follows. Given any input x on the tape of M, the initial portion of the tape that holds x is read-only and one-way. That is, M cannot write o

cpp programming assignment help, wrap that computes a customer water bill....

wrap that computes a customer water bill. The bill include Rs.100 water demand charge + a consumption charge of Rs.1.5 for every thousand gallons used. Consumption is figured from

Time and space tradeoffs in search, Time and Space Tradeoffs in search-arti...

Time and Space Tradeoffs in search-artificial intelligence: In practice, you need to stop your agent at some stage if it has not searched a solution by then. However, if we can

Mode of nutrition, what type of nutrition,leech is?

what type of nutrition,leech is?

Register array, #queA register is a memory location surrounded by the CPU i...

#queA register is a memory location surrounded by the CPU itself, designed to be rapidly accessed for purposes of fast data retrieval. Processors normally hold a register array, wh

Types of pc, TYPES OF PC:  In general,  basic function of all the comp...

TYPES OF PC:  In general,  basic function of all the computers is same i.e. Computers accept data as input, perform operations on these data and generates the desired output t

Configuration of a pc, Configuration of a PC: Generally, when you thin...

Configuration of a PC: Generally, when you think of purchasing a Computer, you first try to exactly know what will be the hardware components such as processor, memory etc. of

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: +1-415-670-9521

Phone: +1-415-670-9521

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

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