Update assignment content

- Update assignment content to new structure
- Add `grade.sh` script

Signed-off-by: Gabriel Mocanu <viorel.mocanu@upb.ro>

README.md

@@ -43,10 +43,6 @@ no such file or directory
 
 > **_NOTE:_** Using the `cd` command without any arguments or with more than one argument doesn't affect the current directory path.
 > Make sure this edge case is handled in a way that prevents crashes.
->
-> **_BONUS 1:_** You can implement `cd` (without parameters) which will change the current directory to `$HOME` variable, if defined.
->
-> **_BONUS 2:_** You can implement `cd -` which will change the current directory to `$OLDPWD` variable, if defined.
 
 #### Closing the Shell
 
@@ -213,9 +209,31 @@ Tests are located in the `tests/` directory.
 
 ```console
 student@so:~/.../assignment-mini-shell/tests$ ls -F
-Makefile  run_all.sh*  _test/
+Makefile  grade.sh*  run_all.sh*  _test/
 ```
 
+To test and grade your assignment solution, enter the `tests/` directory and run `grade.sh`.
+Note that this requires linters being available.
+The easiest is to use a Docker-based setup with everything installed, as shown in the section ["Running the Linters"](#running-the-linters).
+When using `grade.sh` you will get grades for correctness (maximum `90` points) and for coding style (maximum `10` points).
+A successful run will provide you an output ending with:
+
+```console
+### GRADE
+
+
+Checker:                                                         90/ 90
+Style:                                                           10/ 10
+Total:                                                          100/100
+
+
+### STYLE SUMMARY
+
+
+```
+
+### Running the Checker
+
 To run the checker and everything else required, use the `make check` command in the `tests/` directory:
 
 ```console
@@ -273,7 +291,23 @@ test_01.txt  test_03.txt  test_05.txt  test_07.txt  test_09.txt  test_11.txt  te
 test_02.txt  test_04.txt  test_06.txt  test_08.txt  test_10.txt  test_12.txt  test_14.txt  test_16.txt  test_18.txt
 ```
 
-### Debug
+### Running the Linters
+
+To run the linters, use the make lint command in the `tests/` directory:
+
+```console
+student@so:~/.../assignment-mini-shell/tests/$ make lint
+[...]
+cd .. && checkpatch.pl -f checker/*.sh tests/*.sh
+[...]
+cd .. && cpplint --recursive src/ tests/ checker/
+[...]
+cd .. && shellcheck checker/*.sh tests/*.sh
+```
+
+Note that the linters have to be installed on your system: [`checkpatch.pl`](https://.com/torvalds/linux/blob/master/scripts/checkpatch.pl), [`cpplint`](https://github.com/cpplint/cpplint), [`shellcheck`](https://www.shellcheck.net/) with certain configuration options.
+
+### Debugging
 
 To inspect the differences between the output of the mini-shell and the reference binary set `DO_CLEANUP=no` in `tests/_test/run_test.sh`.
 To see the results of the tests, you can check `tests/_test/outputs/` directory.
@@ -282,4 +316,4 @@ To see the results of the tests, you can check `tests/_test/outputs/` directory.
 
 To inspect the unreleased resources (memory leaks, file descriptors) set `USE_VALGRIND=yes` and `DO_CLEANUP=no` in `tests/_test/run_test.sh`.
 You can modify both the path to the Valgrind log file and the command parameters.
-To see the results of the tests, you can check `tests/_test/outputs/` directory.
+To see the results of the tests, you can check `tests/_test/outputs/` directory.
\ No newline at end of file

tests/grade.sh

+#!/bin/bash
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Grade style based on build warnings and linter warnings / errors.
+# Points are subtracted from the maximum amount of style points (10).
+#   - For 15 or more build warnings, all points (10) are subtracted.
+#   - For [10,15) build warnings, 6 points are subtracted.
+#   - For [5,10) build warnings, 4 points are subtracted.
+#   - For [1,5) build warnings, 2 points are subtracted.
+#   - For 25 ore more linter warnings / errors, all points (10) are subtracted.
+#   - For [15,25) linter warnings / errors, 6 points are subtracted.
+#   - For [7,15) linter warnings / errors, 4 points are subtracted.
+#   - For [1,7) linter warnings / errors, 2 points are subtracted.
+# Final style points are between 0 and 10. Results cannot be negative.
+#
+# Result (grade) is stored in style_grade.out file.
+# Collect summary in style_summary.out file.
+
+function grade_style()
+{
+    compiler_warn=$(< checker.out grep -v 'unused parameter' | grep -v 'unused variable' | \
+        grep -v "discards 'const'" | grep -c '[0-9]\+:[0-9]\+: warning:')
+
+    compiler_down=0
+    if test "$compiler_warn" -ge 15; then
+        compiler_down=10
+    elif test "$compiler_warn" -ge 10; then
+        compiler_down=6
+    elif test "$compiler_warn" -ge 5; then
+        compiler_down=4
+    elif test "$compiler_warn" -ge 1; then
+        compiler_down=2
+    fi
+
+    cpplint=$(< linter.out grep "Total errors found:" | rev | cut -d ' ' -f 1 | rev)
+    checkpatch_err=$(< linter.out grep 'total: [0-9]* errors' | grep -o '[0-9]* errors,' | \
+        cut -d ' ' -f 1 | paste -s -d '+' | bc)
+    checkpatch_warn=$(< linter.out grep 'total: [0-9]* errors' | grep -o '[0-9]* warnings,' | \
+        cut -d ' ' -f 1 | paste -s -d '+' | bc)
+    if test -z "$checkpatch_err"; then
+        checkpatch_err=0
+    fi
+    if test -z "$checkpatch_warn"; then
+        checkpatch_warn=0
+    fi
+    checkpatch=$((checkpatch_err + checkpatch_warn))
+    checker_all=$((cpplint + checkpatch))
+
+    checker_down=0
+    if test "$checker_all" -ge 25; then
+        checker_down=10
+    elif test "$checker_all" -ge 15; then
+        checker_down=6
+    elif test "$checker_all" -ge 7; then
+        checker_down=4
+    elif test "$checker_all" -ge 1; then
+        checker_down=2
+    fi
+
+    full_down=$((compiler_down + checker_down))
+
+    if test "$full_down" -gt 10; then
+        full_down=10
+    fi
+    style_grade=$((10 - full_down))
+
+    echo "$style_grade" > style_grade.out
+
+    {
+        < linter.out grep -v 'unused parameter' | grep -v 'unused variable' | grep -v "discards 'const'" | \
+            grep '[0-9]\+:[0-9]\+: warning:'
+        < linter.out grep "Total errors found: [1-9]"
+        < linter.out grep 'total: [1-9]* errors'
+        < linter.out grep 'total: 0 errors' | grep '[1-9][0-9]* warnings'
+    } > style_summary.out
+}
+
+# Print grades: total, checker and style.
+# Style grade is only awarded for assignments that have past 60 points
+# of th checker grade.
+print_results()
+{
+    checker_grade=$(< checker.out sed -n '/^Checker:/s/^.*[ \t]\+\([0-9\.]\+\)\/.*$/\1/p')
+    if test "$(echo "$checker_grade > 60" | bc)" -eq 1; then
+        style_grade=$(cat style_grade.out)
+    else
+        style_grade=0
+    fi
+    final_grade=$(echo "scale=2; $checker_grade+$style_grade" | bc)
+    echo -e "\n\n### GRADE\n\n"
+    printf "Checker: %58s/ 90\n" "$checker_grade"
+    printf "Style: %60s/ 10\n" "$style_grade"
+    printf "Total: %60s/100\n" "$final_grade"
+
+    echo -e "\n\n### STYLE SUMMARY\n\n"
+    cat style_summary.out
+}
+
+run_interactive()
+{
+    echo -e "\n\n### CHECKER\n\n"
+    stdbuf -oL make check 2>&1 | stdbuf -oL sed 's/^Total:/Checker:/g' | tee checker.out
+
+    echo -e "\n\n### LINTER\n\n"
+    stdbuf -oL make lint 2>&1 | tee linter.out
+
+    grade_style
+    print_results
+}
+
+run_non_interactive()
+{
+    make check 2>&1 | sed 's/^Total:/Checker:/g' > checker.out
+    make lint > linter.out 2>&1
+
+    grade_style
+    print_results
+
+    echo -e "\n\n### CHECKER\n\n"
+    cat checker.out
+
+    echo -e "\n\n### LINTER\n\n"
+    cat linter.out
+}
+
+# In case of a command line argument disable interactive output.
+# That is, do not show output as it generated.
+# This is useful to collect all output and present final results at the
+# beginning of the script output.
+# This is because Moodle limits the output results, and the final results
+# would otherwise not show up.
+if test $# -eq 0; then
+    run_interactive
+else
+    run_non_interactive
+fi