If you use more than 3 lines of code from the internet, cite them in a comment. It's cause for an 'f' otherwise!!!!
THIS IS OUT OF 20 POINTS!!!! No one can get more than 20 points.
If you work in pairs, then I'll give each person 2/3 of the total points. So if a team gets 30 (and each person gets 15), I'll give each student 20.
If you work in threes, then I'll give each person 1/2 of the total points. So if a team gets 40 (and each person gets 13.3333), I'll give each student 20.
The Shell Assignment (total 42 points)
- 1
Can run an executable/bin/ls
- 1
You search the path for the executablels
- 1
Can do file input redirection "<"ls > fred
- 1
Can do file output redirection ">"ls < fred
- 2
Can do command piping "|"ls | wc
- 1
Can do lots of pipesls | grep fred | wc
- 1
Can do at least one combination of these thingsls | wc > fred
- 4
Can do any combination of three of <, >, and |cat < filename | sort > sortedFile.txt
- 2 Can set enviornment variables
PATH=:/bin:/sbin:/usr/sbin:/usr/bin
- 2
Expands enviornment variables on the command linels $HOME
- 2
Does filename expansion "glob" (Hint: Use the built in glob.)ls a*b
- 1
Knows how to change directorycd /fred
- 1 Bang last command
!l
runs ls
- 1 Bang # command
!4
runs 4th command from history
- 1
Queue commandsmake ; make install
- 1
Can have lots of semicolonsls; sleep 3; rm fred
- 2 Change Prompt
PS1="what is you command?"
- 3 Can run commands in the background.
processImage &
- 1 Concatenate commands with &. Only runs next command if the previous
comand returned success.
cd /home/rappleto & rm fred.txt
- 1
Catch Keyboard interruptctrl + c
= back to prompt
- 1
Replace "~" with the home directoryrm ~/junkfile
- 1
Control-L clears the screenctrl-l
= clear screen
- 3 When they misspell a command, offer a suggestion
- (user)
lss
- (shell) Did you mean
ls
?
- (user)
- 2 Can run commands from a file
. scriptFile.txt
- 2
Tab CompletionandArrow History - 1
Saves and reloads history to a file - 2 Automatically runs a file called .myshell when it starts
- 2 Only runs execuatables from an approved list
- -2 Commands cannot have arguments (i.e. ls -l does not work).
25 pts /20
Some cases to consider
- A person tries to run a non-executable.
- A person tries to read or write to a non-existent file.
- A person tries to read or write to a file they do not have permissions on.
- A person tries a non-sensical command. (i.e.
ls > foo > fee < doo < dee
) - A person tries to pipe to a non-command (i.e.
ls | /tmp/foo.txt
) - A person tries to pipe from a non-command (i.e.
/tmp/foo | ls
) - A person tries to expand a non-variable (i.e.
ls $DOES_NOT_EXIST
) - A regular expression matches no files.
- A regular expression matches one file.
- A regular expression matches lots of files.
- A person tries to change directory to something that does not exist.
These programs are due Friday before finals week. It will take a totally excellent excuse to move this at all.