mdarc is a command line tool written in C for archiving and compressing a list of files into an single archive file. It can also unarchive the created file into its original contents.
Additionally there are several options that can be used like using a password to encrypt the created archive, recurse into directories, add or remove files from an existing archive as well as list the archive contents without extracting the archived files files.
mdarc [command] (options) (password) [archive name] [file1] [file2] ... [dir1] [dir2] ...
archive - Archive specified files into an archive named
- -a - Add files to existing archive. If the newlly added filename already exists in the archive, it will be overwritten. /TODO/
Note - Unless the -a option is specified and the archve name already exists, the existing archive file will be overwritten. - -d - Delete files from existing archive. /TODO/
- -r - Recurse into directories. /TODO and also figure out logic, wildcards etc./
- -p - Encrypt using a password, which must be provided immediately after the options, before the archvie name. /TODO/
unarchive - Unarchive the specified archived file.
- -l - List the files in the archive without extracting its contents. /TOOD/
- -p - For extracting a password protected archive. -p and corresponding password must be used for a password protected archive, otherwise an error will be displayed. /TODO/
Options can be combined as follows:
mdarc archive -ap pass123 archive_name.arc file1 file2
The above syntax combines options -a and -p and will create an archive named archive_name.arc containing file1 and file2 encrypted with password pass123.
The program is useful for packaging a set of files for archiving files; for distribution; and for saving disk space by temporarily compressing unused files or directories.
The mdarc program puts one or more compressed files itno a single archive along with information about the files (original name and path). An entire directory structure can be packaged into an archive with a single command.
The program uses the DEFLATE compression method (utilizing the zlib library) with compression ratios of 2:1 to 3:1 being common for text files.
/TODO/
Parsing command line arguments using the getopt function: Initially I planned to use global boolean variables to store the different options, but realized this is not a good practice (globals can make the code more error-prone and using separate varaibles will make it more difficult to read and maintain. Especially if new options are to be added in the future). I ended up using a struct containing fields for different options, parsing them using getopt in main() and passing a pointer to the struct to functions that access to it. Benefits - more organized code and reduced chance of conflicing globals, passing a single argument for options to various functions, avoid having to re-parse options if the code grows in complexity, easier to add new options.
/TODO/
? - match any single character
-
- match any number of characters (including none)
- file path is limited to 256 characters
Program supports archiving and unarchiving. File names must be listed individuallly. No options support yet. Basic parsing of command line arguments and file list is passed to archive_files function as &argv[3] (address of first filename)
- Implement a struct to keep all command line arguments in one place - commands, options, passwords, archive name and a file list.
- Externalize parsing command line arguments into a separate function.
- Externalize printing program syntax into a separate function
- Update functions input to use the options struct. No actual options support yet, getopt() to be implemented in next version.