Cat & Grep

Table of contents

• Introduction
• Goals
• Build
• s21_cat
  • s21_cat usage
  • s21_cat options
  • s21_cat tests
• s21_grep
  • s21_grep usage
  • s21_grep options
  • s21_grep tests
• Credits

Introduction

Implementation of GNU cat and BSD grep.

Goals

• Understand file processing in C
• Implement error handling in C
• Parsing of command line arguments
• Become familiar with the regex.h
• Implement integration tests

Build

$ git clone https://github.com/bezlant/s21_cat_grep
$ cd s21_cat_grep/src/
$ make

S21_cat

s21_cat Usage

$ s21_cat [OPTION] [FILE] ...

s21_cat Options

No.	Options	Description
1	-b (GNU: --number-nonblank)	numbers only non-empty lines
2	-e implies -v (GNU only: -E the same, but without implying -v)	but also display end-of-line characters as $
3	-n (GNU: --number)	number all output lines
4	-s (GNU: --squeeze-blank)	squeeze multiple adjacent blank lines
5	-t implies -v (GNU: -T the same, but without implying -v)	but also display tabs as ^I

s21_cat Integration tests

s21_cat fully replicates original GNU cat functionality, including all major flags. Before launching tests s21_cat executable must be built.
Integration tests are launched via bash script cat/run_tests.sh.

$ ./run_tests.sh

This was developed on MacOS, some tests may fail on other systems

S21_grep

s21_grep Usage

s21_grep [OPTIONS] template [FILE] ...

s21_grep Options

No.	Options	Description
1	-e	pattern
2	-i	Ignore uppercase vs. lowercase.
3	-v	Invert match.
4	-c	Output count of matching lines only.
5	-l	Output matching files only.
6	-n	Precede each matching line with a line number.
7	-h	Output matching lines without preceding them by file names.
8	-s	Suppress error messages about nonexistent or unreadable files.
9	-f file	Take regexes from a file.
10	-o	Output the matched parts of a matching line.

s21_grep Integration tests

s21_grep replicated major BSD grep (2.5.1-FreeBSD) flags and their combinations listed above.

Integration tests are launched via C program test/test_combinations.c or grep/run_tests.sh bash script. Before launching tests s21_grep executable must be built. There are about ~4k tests.

$ make testus
$ cd test && ./testus

This was developed on MacOS, some tests may fail on other systems

Credits

• Developer: Anton Bezludniy (@tarticar)
• I greatly appreciate Stepan Fedorov (@nanadaug) & Andrey Zhelannikov (@capricey) for providing C & Python scripts for testing.
• Special thanks to Mikhail Kuznetsov (@posidoni) for the inspiration to write nice readme's :)