C-SHELL

Usage

Compile the shell:

> make all

Run the shell:

> ./a.out

Remove executable and intermediate files made such as .log and *.txt (NOTE: keeps .myshrc):

> make clean

Assumptions:

PART-A: Basic System Calls

1. Maximum lengths of some strings are assumned and present in ./utils/settings.h
2. In hop: upon command hop main -, it will treat main as previous directory.
3. Background processes are handled using an array of structs ProcessInfo instead of any hidden files.
4. For processes, to which linux doesn't allow to retrieve executable path, error is printed. Although using sudo allows to find the path.
5. reveal - will throw an error: ERROR: command reveal: Found operator "-" but not flags such as "l" or "a"
6. reveal -l ; reveal - would first split the command into two, execute the first splitted command, then throw similar error as 5th point for second splitted command.
7. All erroneous commands are also stored in .log.
8. hop .. &: here '&' will be treated as argument instead of background process. (can be generalized for all custom commands)

PART-B: Processes, Files and Misc

1. log file stores the alias intead of actual command that is decoded using myshrc.
2. hop .. | wc would first hop to parent directory then output (if any) is piped to wc.
3. ctrl + D command can be triggered by using commands exit or logout.

PART-C: Networking

None

Specifications and corresponding files:

PART-A: Basic System Calls

Driver: main.c

SPEC 1 - Display Requirements: prompt.c, processInput.h

SPEC 2 - Input Requirements: processInput.c, processInput.h

SPEC 3 - hop: hop.c, hop.h

SPEC 4 - reveal: reveal.c, reveal.h

SPEC 5 - log commands: log.c, log.h

SPEC 6 - System Commands: sysCmnds.c, sysCmnds.h, bgHandler.c, bgHandler.h, fgHandler.c, fgHandler.h

SPEC 7 - proclore: proclore.c, proclore.h

SPEC 8 - seek: seek.c, seek.h

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PART-B: Processes, Files and Misc

SPEC 9 - myshrc: myshrc.c, myshrc.h

SPEC 10 - I/O Redirection: processInput.c, processInput.h

SPEC 11 - Pipes: main.c, processInput.c, processInput.h

SPEC 12 - Redirection along with pipes: main.c, processInput.c, processInput.h

SPEC 13 - activities: bgHandler.c, bgHandler.h

SPEC 14 - Signals: signals.c, signals.h

SPEC 15 - fg and bg: bgHandler.c, bgHandler.h, fgHandler.c, fgHandler.h

SPEC 16 - Nenoate: Not done

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PART-C: Networking

SPEC 17 - iMan: iMan.c, iMan.h

Notes:

1. Run sudo ./a.out, if want to let readlink work on every file (even files to which access are denied). Useful for cases like proclore 1, ...

2. For Activites, we know that the only processes which can be currently running are the background processes only. So printing all the background processes currently running in the shell would suffice.