User Account

All Pages

Unix, Programming Languages

Assignment Help:
1. Write a shell script to locate executable files. This script takes a list of file names from the command line and determines which would be executed had these names been given as commands.
• The search path should be based only on the user''s PATH environment variable. You shall not use the Unix which command, the ksh whence (type) command, or the bash type command.
• The script should find only the first occurrence of the "file". If the file is not found, the script should print an error message that the file was not found in the user''s path. (Both the filename and the users path should be printed.)
• If the first parameter is ''-a'', then the script should print all occurrences of the executable file in the user''s path. Again if the file was not on the path, an error message should be displayed.
• The find command shall not be used.
• A project using temporary files will not be graded.
Note:
• The shell variable PATH defines the search path for the directory containing the command. Alternative directory names are separated by a colon (:). The current directory can be specified by two or more adjacent colons, or by a colon at the beginning or end of the path list.
• If the command name contains a / then the search path is not used. Otherwise, each directory in the path is searched for an executable file.
usage: mywhich [-a] command ....
Examples: The locations of these programs may vary on different systems and the users PATH environment variable.
prompt> mywhich ls
/bin/ls
prompt> mywhich -a cc
/bin/cc
/usr/ucb/cc
prompt> mywhich ./mywhich
./mywhich
prompt> mywhich fooblar
fooblar not found
prompt> mywhich ksh sh csh bash
/usr/bin/ksh
/bin/sh
/bin/csh
/usr/local/bin/bash

2.Write a shell script to concatenate lists together, and output the resulting list. Do not include any argument that is a sub-list of the entire list. (The script will clean the list of any redundant items.) You must preserve the original order of the list. Remember to account for the following situations:
• a : at the beginning of the list is the same as a . at the beginning of the "list" (:/bin is the same a .:/bin)
• a :: any where in the list is the same as :.: (/bin::/etc is the same as (/bin:.:/etc)
• a : at the end of the list is the same a :. ( /bin: is the same as /bin:. )
• Project usings temporary files will not be graded.
• The input to the script will be color or space separated lists and the output will be a colon separated list with the orignal order preserved and all redunant items removed.

USAGE: clean_list list ....
Where list a a colon or whitespace separated list.


Examples:
prompt> clean_list a a:b a:b:c :x: y:z
a:b:c:.:x:y:z

prompt>clean_list /bin:/usr/bin:/usr/openwin/bin /usr/bin:/usr/etc:/etc: /usr/bin/X11 .:/bin
/bin:/usr/bin:/usr/openwin/bin:/usr/etc:/etc:.:/usr/bin/X11

prompt>clean_list apple:orange:apple pear orange peach
apple:orange:pear:peach

________________________________________
REMEMBER TO HANDLE THE SPECIAL CASES OF LEADING :, A ::, AND A TRAILING :

3.
Assignment 3
------------------------------------------------------------------------
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
Examples:


prompt> change-lines -s foobar -r FooBar *.c
This script will edit all the files *.c, and each occurrence of foobar it will be replaced by FooBar it will be replaced by FooBar.
Each file will be backed up.


prompt> change-lines -s "SHELL IS NOT FUN" -r "SHELL PROGRAMING IS A LOT OF FUN" /tmp/file1.txt


This script will edit all the file /tmp/file1.txt , and each occurrence of SHELL IS NOT FUN will replaced by the text,
SHELL PROGRAMMING IS A LOT OF FUN. A backup file /tmp/file1.txt.keep will be created.


------------------------------------------------------------------------
I want you to modify the following program
https://ce.uml.edu/~mrichard/hw/p3-hints.txt
If you do not use the program listed above as the basis for the assignment, your assignment will NOT be graded.

Follow the my shell programming guidelines as in the other assignments.
Write a shell script to send a customized mail message to the users listed on the command line by login (user) name, only if they are currently logged on.
• If no users are listed on the command line an error message should be printed.
• In the mail message, you should use the full (real) name from the passwd file (/etc/passwd).
• You also need to sign the script with the real name of the person who is running the script.
•
o This can be derived from the $USER environment variable and looking up the value in the password file.
• An error message should be printed if the user does not exist in the passwd file.
• PLEASE ONLY SEND THIS MESSAGE TO USERS WHICH YOU KNOW PERSONALLY.
•
o You can always use yourself and me (mrichard) as a test case
o The real name of the user of the script should only be computed once.
• A "Here-Document (In-Line Redirection)" must be used for the mail message.
• No temporary files shall be used.
The message should be as follows:
Hello ,
**** This email is automatically generatated by ******
My instructor requires that I send this message as part of an assignment for class 92.312.
The current time and date is .
Have a nice day.

Related Discussions:- Unix

Operating systems, I do have an assignment in operating systems programming...

I do have an assignment in operating systems programming ... how can i attach my file?

The .net framework 3.5, Architecture and Components The .NET Framework 3.5 ...

Architecture and Components The .NET Framework 3.5 The .NET Structure (pronounced dot net) is an application framework that works generally on Enthusiasm Microsoft windows. It has

What do you meant by a function, (a) (i) What do you meant  by a function? ...

(a) (i) What do you meant  by a function? Are functions required when writing a C program? (ii) State one of the advantages to the use of functions. (iii) What do you meant by a

Str_concat procedure, Write a procedure named Str_concat that concatenates ...

Write a procedure named Str_concat that concatenates a source string to the end of a target string. Sufficient space must exist in the target string to accommodate the new characte

Create procedures for accessing the root, (a)  Create procedures for access...

(a)  Create procedures for accessing the root, left subtree and right subtree, and also mutators for changing the root, left subtree and right subtree of an avl argument. (b) Wr

Assembly TASM or MASM, I need help with making a assembly program that uses...

I need help with making a assembly program that uses Hoffman''s coding scheme to compress a text file.

Maze-solving, For this assignment you will use the robot/maze simulation ex...

For this assignment you will use the robot/maze simulation example introduced in mini-assignments 0625ma-0627ma to develop a maze-solving program. The program will read a file cont

Assembly programme , write and compile a simple program in Assembly Languag...

write and compile a simple program in Assembly Language that compute and print student grades for a course.which you can open a file, read from it, and compute the results...using

Shell script to count characters, Normal 0 false false fals...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Programming project, Create a visualization (programming project) and demon...

Create a visualization (programming project) and demonstrate it in the class. The project should be related to distributed systems. (A distributed system consists of multiple auton

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