CS253 HW3: Arguments, reading from files                

CS253 HW3: More Censorship                

Changes                

Updates to the assignment will be noted here. None yet!                 

Description                

For this assignment, you will write a C++ program called hw3 that improve on your HW1 work. Instead of always just censoring those Greek letter words, it will censor a given list of words. In addition, it will read from given files, or standard input if no files are given.                 

Arguments                

The arguments to hw3 must be, in this order:

• a possibly-empty list of words to censor
• a mandatory dash (the single character “-”)
• an optional list of files to read from

Words                

Only replace a complete word. We define a word as a sequence of letters, a…zA…Z, delimited (bordered) by non-letters, or the start/end of the line. If we’re censoring the word “foo”, then input such as “fooYMP” must not be changed, but “foo3145727” must be.                 

Sample Run                

Here is a sample run, where % is my prompt.                 

% cat CMakeLists.txt
cmake_minimum_required(VERSION 3.11)
project(hw3)

# Are we in the wrong directory?
if (CMAKE_SOURCE_DIR MATCHES "[Hh][Ww]([0-9])$"
   AND NOT PROJECT_NAME MATCHES "${CMAKE_MATCH_1}$")
    message(FATAL_ERROR "Building ${PROJECT_NAME} in ${CMAKE_SOURCE_DIR}")
endif()

# Using -Wall is required:
add_compile_options(-Wall)

# These compile flags are highly recommended, but not required:
add_compile_options(-Wextra -Wpedantic)

# Optional super-strict mode:
add_compile_options(-fmessage-length=80 -fno-diagnostics-show-option
    -fstack-protector-all -g -O3 -std=c++17 -Walloc-zero -Walloca
    -Wconversion -Wctor-dtor-privacy -Wduplicated-cond
    -Wduplicated-branches -Werror -Wextra-semi -Wfatal-errors
    -Winit-self -Wlogical-op -Wold-style-cast -Wshadow
    -Wunused-const-variable=1 -Wzero-as-null-pointer-constant)

# add_compile_options must be BEFORE add_executable.

# Create the executable from the source file main.cc:
add_executable(${PROJECT_NAME} main.cc)

# Create a tar file every time:
add_custom_target(${PROJECT_NAME}.tar ALL COMMAND
    tar -cf ${PROJECT_NAME}.tar *.cc CMakeLists.txt)
% cmake . && make
… cmake output appears here …
… make output appears here …
% cat poem
Roses are red
Violets are 177777
This poem is too short
% ./hw3 - poem
Roses are red
Violets are 177777
This poem is too short
% ./hw3 Violets foo short - poem /etc/hostname
Roses are red
CENSORED are 177777
This poem is too CENSORED
greybull
% echo 'if (a*a+b*b == c*c) {' | ./hw3 a c -
if (CENSORED*CENSORED+b*b == CENSORED*CENSORED) {
% echo "Ignore this" | ./hw3 hello - /dev/null

Standard Input                

If run without any filename arguments or redirection via < or |, then what should hw3 do? It should read from standard input. In this case, since standard input has not been changed with < or |, standard input remains connected to the keyboard. The program will appear to stop, but it is simply reading from the keyboard.                 

When that happens, the user has two options:

• Type control-C, which stops the current program. It’s also useful if your program goes into an infinite loop.
• Type some input for the program, as it’s expecting. When you're done, press control-D, which indicates end-of-file at a keyboard.

    export STACK_FRAME_LINK_OVERRIDE=ffff-ad921d60486366258809553a3db49a4a

Requirements                

• Error messages:
  • go to standard error
  • include the program name as given by argv[0].
  • stop the program
• If multiple things are bad, pick one, complain, and stop. You don’t have to mention all problems.
• If a required argument is missing, produce an appropriate error message.
• If any word given in argv as a word to censor is not purely alphabetic, produce an error message, containing the bad argument.
• If any word given in argv as a word to censor is given more than once, produce an error message, containing the bad argument.
• If any filename given in argv isn’t readable, produce an error message, containing the bad filename.
• Input format:
  • The input may consist of any number of lines.
  • Each input line may be arbitrarily long.
• Creativity is a wonderful thing, but your output format is not the place for it. Your output should look exactly like the output shown above.
  • UPPERCASE/lowercase matters.
  • Spaces matter.
  • Blank lines matter.
  • Extra output matters.
• You may not use any external programs. You many not use system(), fork(), popen(), execl(), execvp(), etc.
• You may not use C-style I/O such as printf(), scanf(), fopen(), and getchar().
  • Instead, use C++ facilities such as cout, cerr, and ifstream.
• You may not use endl. Use flush if needed.
• You may not use dynamic memory via new, delete, malloc(), calloc(), realloc(), free(), strdup(), etc.
  • It’s ok to implicitly use dynamic memory via containers such as string or vector.
• You may not use the .eof() method.
• No global variables.
  • Except for an optional single global string called program_name containing argv[0].
• For readability, don’t use ASCII int constants (65) instead of char constants ('A') for printable characters.
• We will compile your program like this: cmake . && make
  • If that generates warnings, you will lose a point.
  • If that generates errors, you will lose all points.
• There is no automated testing/pre-grading/re-grading.
  • Test your code yourself. It’s your job.
  • Test with the CSU compilers, not just your laptop’s compiler.
  • Even if you only change it a little bit.
  • Even if all you do is add a comment.

If you have any questions about the requirements, ask. In the real world, your programming tasks will almost always be vague and incompletely specified. Same here.                 

Tar file                

• For each assignment this semester, you will create a tar file, and turn it in.
• The tar file for this assignment must be called: hw3.tar
• It must contain:
  • source files (*.cc)
  • header files (*.h) (if any)
  • CMakeLists.txt
• This command must produce the program hw3 (note the dot):

    cmake . && make

• At least  -Wall must be used every time g++ runs.

Remember how HW0 went on & on about testing your tar file? It applies here, too, and also to all other assignments.                 

How to submit your work:                

In Canvas, check in the file hw3.tar to the assignment “HW3”. It’s due 11:59ᴘᴍ MT Saturday, with a five-day late period.                 

How to receive negative points:                

Turn in someone else’s work.