Language : C

Description:

You will develop a small "text-based shell utility" ("ts") for Unix (or similar OS). A common complaint of the most-used UNIX (text) shells (Bourne, Korn, C) is that it is difficult to remember (long) file names, and type "long" command names. A "menu" type shell allows a user to "pick" an item (file or command)from a "menu".

You will display a simple menu, the following is a suggestion (you may change format):

Current Working Dir: /home/os.progs/Me

It is now: 22 August 2018, 5:30 PM Files: 0. ts.c

1. a.out

2. ts.txt

3. assignment1

4. program2.c Directories: 0. ..

1. my_dir Operation: D Display

E Edit

R Run

C Change Directory

S Sort Directory listing

M Move to Directory

R Remove File

Q Quit You will read a single key "command" entered by the user, then a file or directory number or partial file name with completion and ts will output some system information on the terminal, or run a program (by means of systems calls).

The commands you will implement: Edit opens a text editor with a file.

Run - runs an executable program. You should handle parameters.

Change changes working directory.

Sort sorts listing by either size or date (prompt user)

You will need to implement:

Prev, Next, and Operations need to be merged (menu fits on one screen).

Store names in an array, Only one pass through directory.

Add a menu using terminal codes or curses (ncurses).

(First use initscr(), then move(), printw(), refresh(), getch(), and endwin() ) If the "ts" program has an argument, use it as the directory starting point (working dir), like: "./ts /bin". You should provide a reasonable user interface. (See below) You may write this in ADA, Assembler, C, C++ or Java.(Others with permission) You should target ts to Unix, MacOS, (or similar), or discuss alternatives with instructor.

Constraints:

How many files and directories can you handle (max 1024)

How long is a file name (max 2048 characters, really: limits.h, NAME_MAX)

Bonus:

Show additional file information (date, size, read/execute)

Use file name completion as well as a number.

Create/use a pull-down menu.

Hints: (you may use this code) /* Some example code and prototype - contains many, many problems: should check for return values (especially system calls), handle errors, not use fixed paths, handle parameters, put comments, watch out for buffer overflows, security problems, use environment variables, etc. */ #include

#include

#include

#include

#include

#include

#include

#include int main(void)

{

pid_t child;

DIR * d;

struct dirent * de;

int i, c, k;

char s[256], cmd[256];

/* fixed length buffers? */

time_t t;

while (1)

{

t = time( NULL );

printf( "Time: %s ", ctime( &t ));

getcwd(s, 200); /* why 200? What if bigger? Check for errors? */

printf( " Current Directory: %s ", s); d = opendir( "." ); /* errors? More below */

c = 0;

while ((de = readdir(d)))

{

if ((de->d_type) & DT_DIR)

printf( " ( %d Directory: %s ) ", c++, de->d_name);

}

closedir( d );

d = opendir( "." );

c = 0;

while ((de = readdir(d)))

{

if (((de->d_type) & DT_REG))

printf( " ( %d File: %s ) ", c++, de->d_name);

if ( ( c % 8 ) == 0 )

{

printf( "Hit N for Next " ); /* What if only subdirs? */

k = getchar( );

}

}

closedir( d );

printf( "----------------------------------------- " );

c = getchar( );

getchar( );

switch (c)

{

case 'q': exit(0); /* quit */

case 'e': printf( "Edit what?:" );

scanf( "%s", s );

strcpy( cmd, "pico ");

strcat( cmd, s );

system( cmd ); /*this is bad, should use fork() then execv() or execl() */

break;

case 'r': printf( "Run what?:" );

scanf( "%s", cmd );

system( cmd );

break;

case 'c': printf( "Change To?:" );

scanf( "%s", cmd );

chdir( cmd ); /* what can go wrong ? */

break;

}

}

}