Mini Lib Project

This project implements a minimalistic library that provides basic functionalities such as memory management, string handling, file operations, and shell-like utilities. It mimics some of the basic system commands and provides simple I/O operations.

Project Structure

Header File (mini_lib.h)

The mini_lib.h file contains definitions, structures, and function prototypes for memory management, string manipulation, file handling, and shell-like commands.

Key Structures

• malloc_element: Represents an allocated memory block and its status (used or free).
• MYFILE: Represents an open file, its buffers, and file descriptor.

Memory Management Functions

• mini_calloc: Allocates memory for an array of elements and initializes it to zero.
• mini_free: Frees a previously allocated memory block.
• mini_exit: Terminates the program and cleans up.

String Functions

• real_mini_printf: A simple printf function that prints multiple strings using variadic arguments.
• mini_scanf: Reads user input into a buffer.
• mini_strlen: Computes the length of a string.
• mini_strncpy: Copies a string to another buffer with a size limit.
• mini_strtok: Tokenizes a string based on delimiters.
• Additional functions include mini_strnlen, mini_strcpy, mini_strncmp, mini_strcmp, mini_perror, mini_itoa, mini_atoi, mini_strstr, and mini_strchr.

File Operations

• mini_fopen: Opens a file with a specified mode ('r' for read, 'w' for write).
• mini_fread: Reads data from a file into a buffer.
• mini_fwrite: Writes data from a buffer to a file.
• mini_fflush: Flushes the write buffer of a file.
• mini_fclose: Closes a file and removes it from the open file list.
• mini_fgetc: Reads a single character from a file.
• mini_fputc: Writes a single character to a file.
• Helper functions include adding and removing files from the open files list.

Shell-like Commands

• mini_touch: Creates an empty file if it doesn't exist.
• mini_cp: Copies contents from source file to destination.
• mini_cat: Displays the contents of a file.
• mini_head: Displays the first N lines of a file.
• mini_tail: Displays the last N lines of a file.
• mini_clean: Clears or creates an empty file.
• mini_wc: Counts the number of words in a file.
• mini_echo: Displays a string to the screen.
• mini_grep: Searches for a word in a file and displays matching lines.
• mini_ls: Lists the contents of a directory.
• mini_chmod: Changes the permissions of a file or directory.
• mini_mkdir: Creates a directory.
• mini_mv: Renames or moves a file/directory.
• mini_rm: Removes a file.
• mini_rmdir: Removes a directory.
• mini_quickdiff: Compares two files and reports if they are identical.
• mini_cd: Changes the current directory.
• mini_env: Prints all environment variables.
• mini_getenv: Prints the value of a specified environment variable.
• mini_export: Adds or modifies an environment variable.
• mini_pwd: Prints the current working directory using low-level system calls.

Error Handling

• error_message: Returns a message describing the last error encountered.
• mini_perror: Prints a system error message followed by a custom message.

Constants

• MEM_FAIL: Error message for memory allocation failure.
• USED, FREE, NOT_INIT: Memory block states.
• BUF_SIZE, IOBUFFER_SIZE, MAX_ARGS, MAX_PATH: Buffer and argument sizes.
• ERROR_MAX: Maximum length for error messages.

Usage

The library provides various functionalities that can be used in C programs for basic operations like memory management, file handling, and interacting with the operating system.

• To use the library, include the mini_lib.h header file in your source code.
• Compile the code with the necessary source files to link the functions.

Makefile

The Makefile is located in the src/SHELL directory. Use it to build the project:

cd src/SHELL
make          # Build all utilities
make test     # Run basic functionality tests
make clean    # Remove compiled files

Recent Improvements

The project has been thoroughly reviewed and the following issues have been fixed:

Code Quality Improvements

• Fixed memory management: All malloc/free calls replaced with custom mini_calloc/mini_free
• Corrected function parameter order in mini_strcpy and mini_strncpy
• Fixed buffer management in file I/O operations
• Added proper null-termination in string operations
• Fixed compilation warnings and errors with modern compiler flags

Professional Structure

• Added comprehensive error handling throughout the codebase
• Improved Makefile with proper compilation flags (-Wall -Wextra -std=c99 -pedantic -g)
• Added automated test suite in Makefile
• Fixed header file declarations to match implementations
• Added proper feature test macros for POSIX compliance

Functionality Fixes

• Fixed file descriptor leaks by properly tracking open files
• Corrected mini_pwd implementation to use standard getcwd
• Fixed mini_export function with proper environment variable handling
• Added proper newline handling in output functions
• Fixed memory leaks in buffer allocations

Testing

• All utilities compile without warnings
• Basic functionality tests pass
• Interactive shell works correctly
• File operations (read/write/copy) function properly
• Directory operations work as expected

The project now compiles cleanly with modern C standards and runs reliably.