FileTools

FileTools is a command-line utility written in C that provides a collection of file management and manipulation operations. It supports basic file handling, text manipulation, file comparison, logging, and password-based encryption/decryption.

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Features

Core File Operations

• Create File
  -n <filename>...
  Creates one or more new files with the specified names.

• Copy File
  -cpy <source> <destination>
  Copies the contents of a source file into a new destination file.

• Delete File
  -df <filename>...
  Deletes one or more files.

• Show File Contents
  -o <filename>
  Displays the contents of a file.

• Append Line
  -a <filename> <text>
  Appends a new line containing the specified text to the end of a file.

• Insert Line
  -i <filename> <line> <text>
  Inserts a line of text at a specified line number in a file.

• Delete Line
  -dl <filename> <line>
  Deletes a specific line from a file.

• Count Lines
  -cl <filename>...
  Displays the number of lines in each specified file.

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Additional Operations

• Show Help
  -h
  Displays help information for the program.

• Rename File
  -r <source> <destination>
  Renames a file by copying it to a new file and deleting the original.

• Compare Files
  -cmp <file1> <file2> ...
  Compares files line by line. Differences are reported by line number.
  When multiple files are supplied, each is compared against the first file.

• Show Change Log
  -log
  Displays the change log stored in log.txt.

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Encryption and Decryption

• Encrypt File
  -enc <filename>

• Decrypt File
  -dec <filename>

How It Works

• The user is prompted to enter a password.
• A 128-bit encryption key is derived from the password using PBKDF2 with:
  • A randomly generated 128-bit salt
  • SHA-256 as the hashing function
• The file contents are encrypted using a bitwise XOR cipher with the derived key.
• The encrypted file format is:

[16-byte salt][encrypted content]

• During decryption:
• The first 16 bytes are read as the salt
• The same key is regenerated using PBKDF2
• XOR is applied again to recover the original content

⚠ Important:
Decryption with an incorrect password is destructive. No integrity or password validation is performed.

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Compiling the Program

Encryption and decryption require the OpenSSL library.

Compile using gcc:

gcc -o fileTools Main.c -lcrypto

Usage

The program is operated entirely via command-line arguments.

Examples:

./fileTools -n file1.txt file2.txt
./fileTools -a notes.txt "New line of text"
./fileTools -cmp file1.txt file2.txt
./fileTools -enc secrets.txt