LEARN MORE...

Clianswered

Content type

User Generated

Subject

Computer Science

School

California State University Sacramento

Course

csc 139

Type

Homework

Uploaded By

fgneqbanyq96

Pages

Showing Page:

1/11

HomeWork 5, Command Line interpreter

General rules: Create homework, compose specifications or any text by using a common

document-creation tool, such as Microsoft

Word.

Hints: Refer to the wwweb or lecture notes for this class to design, implement, and debug

correctly working SW solutions. Be concise, complete, and precise.

Abstract: Design, implement, explain, test, and debug a simple, but complete command-line

interpreter named cli.

Detail: Design, implement, document, test and run a simple shell, known here as a

command-line interpreter (cli). This tool is invoked via the cli command plus possible

arguments. Commands are operating system commands to be executed under the Unix (or

Linux) OS. Multiple commands are separated from one another by commas, and each may in

turn have arguments. Cli ‘knows’ a list of commands a-priori (predefined). When invoked, cli

checks, whether the first argument is an included, predefined command. If so, cli confirms

this via a brief message. If not, a contrary message is emitted, stating this is not one the

predefined commands. After the message, cli executes all commands in the order listed. After

executing the last command, cli prints the current working directory, i.e. it acts as if the pwd

command had been executed. Sample runs are shown further below.

Multiple commands of cli must be separated from one another by commas. Possible

parameters of any one command are separated from the command itself (and from possible

further parameters) by white space. White space consists of blanks, tabs, or a combination,

but at least 1 blank space. Here some sample runs with single and multiple commands;

outputs are not shown here:

./cli pwd

./cli rm –f temp, mv temp ../temp1

./cli ls –la

./cli rm a.out, gcc sys.c, cp a.out cli

Cli starts out identifying itself, also you the author, and the release date. Then cli prints the list

of all predefine commands. Finally, cli executes all commands input after the cli invocation. For

your own debug effort, test your solution with numerous correct and also wrong inputs,

including commas omitted, multiple commas, leading commas, illegals commands, other

symbols instead of commas etc. No need to show and hand-in your test and debug work.

The output of the cli command “cli pwd” or “./cli pwd” should be as shown below, assuming

your current working directory is ./classes_Sac_State/csc139. Here is the output of a

sample run with a single command line argument:

herbertmayer$ ./cli pwd

hgm cli 4/12/2020

Legal commands: cd exec exit gcc ls man more mv rm pwd sh touch which $path

2 strings passed to argv[]

next string is 'pwd'

new string is 'pwd '

1st cmd 'pwd' is one of predefined.

/Users/herbertmayer/herb/academia/classes_Sac_State/csc139

Here the output of another sample run, also with a single cli:

herbertmayer$ ./cli ls

Showing Page:

2/11

hgm cli 4/12/2020

Legal commands: cd exec exit fork gcc ls man more mv rm pwd sh touch which

$PATH

2 strings passed to argv[]

next string is 'ls'

new string is 'ls '

1st cmd 'ls' is one of predefined.

admin cli.c sac_state_yyy

backup_1_24_2020 docs sac_state_hw

backup_3_9_2020 grades sac_state_xxx

cli l_notes

/Users/herbertmayer/herb/academia/classes_Sac_State/csc139

Interpretation of commands that cli handles can proceed through system(), executed from

inside your C/C++ program cli.

List of all commands supported by your cli:

char * cmds[ ] = {

1"cd",

"exec",

1"exit",

1"gcc",

1"ls",

1"man",

1 "more",

1"mv",

1 "rm",

1 "pwd",

1 "sh",

"touch",

1"which",

"$path"

};

What you turn in:

1. The source program of your homework solution; well commented, preferably one single

file.

2. About four progressively more complex executions of your correctly working cli program,

showing all user input and output.

Showing Page:

3/11

End of Preview - Want to read all 11 pages?

Access Now

Unformatted Attachment Preview

HomeWork 5, Command Line interpreter General rules: Create homework, compose specifications or any text by using a common document-creation tool, such as Microsoft® Word. Hints: Refer to the wwweb or lecture notes for this class to design, implement, and debug correctly working SW solutions. Be concise, complete, and precise. Abstract: Design, implement, explain, test, and debug a simple, but complete command-line interpreter named cli. Detail: Design, implement, document, test and run a simple shell, known here as a command-line interpreter (cli). This tool is invoked via the cli command plus possible arguments. Commands are operating system commands to be executed under the Unix (or Linux) OS. Multiple commands are separated from one another by commas, and each may in turn have arguments. Cli ‘knows’ a list of commands a-priori (predefined). When invoked, cli checks, whether the first argument is an included, predefined command. If so, cli confirms this via a brief message. If not, a contrary message is emitted, stating this is not one the predefined commands. After the message, cli executes all commands in the order listed. After executing the last command, cli prints the current working directory, i.e. it acts as if the pwd command had been executed. Sample runs are shown further below. Multiple commands of cli must be separated from one another by commas. Possible parameters of any one command are separated from the command itself (and from possible further paramete ...
Purchase document to see full attachment

Tags: operating systems Multiple commands predefined command test and debug work illegals commands