sc-im (Spreadsheet Calculator Improvised)

To build sc-im manually, ensure you have the required dependencies installed and follow these steps:

1. Edit the Makefile: Customize src/Makefile based on your system requirements.
2. Compile: Run make within the src directory.
3. Install (Optional): Install the binary to your system using a privileged user.

Required Dependencies

• ncurses (preferably with wide character support)
• bison or yacc
• gcc
• make
• pkg-config and which

Optional Dependencies

• tmux / xclip / pbpaste: For clipboard support
• gnuplot: For plotting
• libxlsxreader: For XLS support
• xlsxwriter: For XLSX export support
• libxml-2.0 and libzip: For XLSX/ODS import support
• lua: For Lua scripting

sc-im uses Vim-like keybindings for navigation and spreadsheet manipulation. Use the following commands to interact with the spreadsheet:

Cell Editing

• =: Insert a numeric value
• \: Insert a text value
• e: Edit a numeric value
• E: Edit a string value
• x: Delete current cell content

Navigation and Selection

• h, j, k, l: Move left, down, up, and right respectively
• goab12: Jump to cell AB12 (replace with target cell)
• v: Select a range using cursor and hjkl keys

Spreadsheet Operations

• ir: Insert row
• ic: Insert column
• dr: Delete row
• dc: Delete column
• yy: Copy (yank) current cell
• p: Paste previously yanked cell or range
• u: Undo last change
• C-r: Redo last change

File and App Management

• :q: Quit the application
• :h: See help
• :w filename.sc: Save current spreadsheet in .sc format

Configuration is handled via the scimrc file. This file must be placed in the ~/.config/sc-im directory.

Example ~/.config/sc-im/scimrc content:

set autocalc
set numeric
set numeric_decimal=0
set overlap
set xlsx_readformulas

For a full list of configuration variables, refer to the internal help file within the application.

You can use sc-im in a pipeline by using the --nocurses flag. In this mode, sc-im reads commands from stdin and can be used for automated processing.

When --nocurses is active, the application will read lines from stdin and send them to the internal interpreter. After processing the input, you can use the --output flag to capture the results.

The sc-im core provides functions to manage the application lifecycle, including initialization, structure management, and clean exit.

• create_structures(): Initializes the internal data structures required for the spreadsheet engine.
• delete_structures(): Cleans up and deallocates the internal data structures.
• exit_app(int status): Terminates the application with the specified exit status.
• main(int argc, char ** argv): The primary entry point for the application.

The application manages several system signals to ensure stability and proper behavior:

• signals(): Sets up the signal handlers.
• sig_int(int signum): Handler for the interrupt signal (SIGINT).
• sig_nopipe(int signum): Handler for pipe-related signals.
• sig_winchg(int signum): Handler for window change signals (SIGWINCH).

Functions for handling application startup via command line arguments or standard input:

• read_argv(int argc, char ** argv): Parses command line arguments.
• read_stdin(): Reads input from standard input.
• handle_argv_exports(): Handles exported arguments/commands.
• show_version_and_quit(): Displays the current version of sc-im and exits.
• show_usage_and_quit(): Displays the command usage information and exits.

The following global variables are exported for access to the application's runtime state:

• fdoutput: A FILE * representing the output file descriptor (typically stdout or a file).
• curmode: An unsigned int representing the current application mode.
• lastmode: An unsigned int representing the previous application mode.
• startup_tv: A struct timeval recording the application startup time.
• current_tv: A struct timeval recording the current runtime time.

The sc-im executable accepts command line arguments to configure its behavior or load specific files.

• Files: Any argument that does not start with -- is treated as a filename to be loaded. If multiple files are provided, the last one is used.
• Parameters: Arguments starting with -- are parsed as configuration parameters and stored in the internal configuration dictionary.
• Special Flags:
  • --help: Displays usage information and exits.
  • --version: Displays the version information and exits.
  • --nocurses: Disables the ncurses TUI, allowing sc-im to run in a non-interactive mode (e.g., for piping input/output).
  • --output <file>: Redirects the application output to the specified file instead of stdout.
  • --export_csv, --export_tab, --export_mkd, --export_txt, --export: Triggers specific export formats upon loading the file.