42sh Wiki

SCL structure

• Shell introduction
• Quoting
  • Escape Character (Backslash) \
  • Single-Quotes '
  • Double-Quotes "
• Token Recognition
  • Alias Substitution
• Reserved Words
• Parameters and Variables
  • Positional Parameters
  • Special Parameters
  • Shell Variables
• Word Expansions
  • Tilde Expansion
  • Parameter Expansion
  • Command Substitution
  • Arithmetic Expansion
  • Field Splitting
  • Pathname Expansion
  • Quote Removal
• Redirection
  • Redirecting Input
  • Redirecting Output
  • Appending Redirected Output
  • Here-Document
  • Duplicating an Output File Descriptor
  • Open File Descriptors for Reading and Writing
• Exit Status and Errors
  • Consequences of Shell Errors
  • Exit Status for Commands
• Shell Commands
  • Simple Commands
  • Pipelines
  • Lists
  • Compound Commands
  • Function Definition Command
• Shell Grammar
  • Shell Grammar Lexical Conventions
  • Shell Grammar Rules
• Signals and Error Handling
• Shell Execution Environment
• Pattern Matching Notation
  • Patterns Matching a Single Character
  • Patterns Matching Multiple Characters
  • Patterns Used for Filename Expansion
• Special Built-In Utilities

Tips

1) Utilities

• tree -I 'venv|build': display all directories execpt venv and build.
• alias ccg="gcc -Wall -Wextra -Werror -pedantic -std=c99 -g -fsanitize=address -o out"

2) Shell

A) To check if command is POSIX-compliant

• run bash --posix in terminal.
• run your command

3) Cmake

A) General

• Add macro to target (ex: _XOPEN_SOURCE >= 500)
  • Conférences 42sh 2019 - Build systems => Timeline 2:16:56
• Include directories to target (ex: gcc -Isrc)
  • Conférences 42sh 2019 - Build systems => Timeline 2:17:39

B) Run Pytest

• First time:
  • Download conftest.py (Renamed if needed) and move it to test folder. (not needed as pierre did it for us)
  • Run python -m venv venv to create env. ( in root of dir)
  • To activate env, run source venv/bin/activate
  • Run pip install pytest pyyaml
  • Run pip install cmake-format (cmake-format -i CMakeLists.txt)
  • To run tests, type pytest
  • Tests are written in a .yaml file (see conftest.py for syntax).
  • To deactivate env, run deactivate
• Other:
  • To activate env, run source venv/bin/activate
  • To run tests, type pytest
  • To deactivate env, run deactivate

C) Run criterion tests

To run criterion testsuite: ctest --verbose or make check (if implemented).

• Suppose the following architecture:

├── CMakeLists.txt  (1)
├── src
│   ├── CMakeLists.txt (2)
│   ├── lexer
│   │   ├── CMakeLists.txt (3)
│   │   ├── lexer.c
│   │   ├── lexer.h
│   │   ├── token.c
│   │   └── token.h
└── tests
    └── utests
        ├── CMakeLists.txt (4)
        ├── lexer
        │   └── lexer_1.c

• In CMakeLists.txt (1), make sure to have:
  • add_subdirectory(src/lexer)
• In CMakeLists.txt (2), make sure to have:
  • target_link_libraries(42sh PRIVATE ${READLINE_LIB} common_options lexer)
• In CMakeLists.txt (3), make sure to have:

add_library(lexer STATIC <--- THIS
 lexer.c
 lexer.h
 token.c
 token.h
)

target_include_directories(lexer PUBLIC .) <--- THIS

target_link_libraries(lexer PRIVATE common_options) <--- THIS

• In CMakeLists.txt (4), make sure to have:

find_library(CRITERION_LIB criterion)

add_executable(test_criterion utests_1.c lexer/lexer_1.c)
                                            ^
                                            `--- THIS
target_link_libraries(test_criterion PRIVATE
    ${CRITERION_LIB}
    common_options
    lexer <-- THIS
)

• In lexer/lexer_1.c, only need to include #include "token.h"

4) Git

A) .git/config

[core]
    pager = less -S

[alias]
    tree = log --graph --decorate --pretty=oneline --abbrev-commit

• git tree: view commit in tree-like view.
• git config --global pull.rebase true: Enable pull rebase.

B) branching

• git branch: Display all existing branches.
• git checkout <branch>: switch branch
• git checkout -b <branch>: create branch + switch branch
• git push --set-upstream origin <branch>: Tells git to push to <branch> and not master.

C) Merge

• git checkout master
• git pull
• git merge <name_branch>

5) Debugging

• In your file test, replace Test(....) by int main(void)
• Run make debug, an executable named utest_criterion will be created.
• Run gdb utest_criterion.
• ALWAYS make clean + rm utest_criterion
  • because the utest_criterion at the root is a copy from the one in test. Thus make clean won't see it.

Valgrind

• At root, mkdir build/
• cd build
• cmake .. -DCMAKE_BUILD_TYPE=Release (This should run version without fsanitize=address)

fsanitize=address

• At root, mkdir debug/
• cd debug
• cmake .. -DCMAKE_BUILD_TYPE=Debug (This should run version with fsanitize=address)

6) Static library linking

• Use -Wl,--start-group and -Wl,--end-group to stop worrying about libraries ordering.

target_link_libraries(
  utest_criterion
  PRIVATE ${CRITERION_LIB}
          common_options
          "-Wl,--start-group"
          ast
          execution
          option_parser
          parser
          lexer
          data-structure
          utils
          "-Wl,--end-group")

7) Doxygen (manpage)

• if you want to have acces to manpage from root, use the command : groff -man -Tascii doc/42sh.man | less
• Updates can and MUST be done, it can be manipulated like a .txt document in vim/emacs.

Miscellaneous

• Shell architecture (made by ex-ACU)
• Check if script is posix compliant (use !/bin/sh)
• Example to clarify interpretation and syntax of shell grammar
• Layman explication of Token Recogntion && Shell Grammar sections
• Variables en shell Bash
• bash-cheatsheet
• bash: all about redirections

Conferences

• Shell Grammar conference
• Tests UFOs did it: learning about the test pyramid (python too)
• Python & Testsuite fonctionnelle
• Gaby conf achitecture shell