Digital Colors (dc)

dc is a command-line utility that enhances terminal output by adding colorization. It's designed to highlight common data formats like XML and JSON, as well as patterns such as log levels and timestamps.

You can use dc in two main ways:

1. As a command wrapper: dc your_command [args...]
   • dc executes your_command and colorizes its standard output.
2. As a pipe processor: your_command | dc
   • dc reads data from standard input (stdin), colorizes it, and prints it to standard output (stdout).

Installation

npm i -g @s-a/digital-colors

Usage Modes

Mode 1: Executing a Command and Colorizing its Output

(dc your_command [args...])

When you provide dc with a command to run, it executes that command, captures its standard output, and applies colorization before printing it to your terminal.

Key Characteristics:

• The first argument after dc is the command to be executed (e.g., tail, ls, cat).
• Any subsequent arguments are passed directly to that command.
• This mode is ideal for colorizing the output of commands directly, including long-running processes like tail -f.

Examples:

• Live Log Monitoring (most common use case): To monitor a log file with tail -f and have its output colorized:

  dc tail -f /path/to/your/logfile.log

  (For Windows, use appropriate paths like D:\\log\\api.log)

• Colorizing Output of Short-Lived Commands:

  dc ls -la

  dc cat /etc/hosts

Mode 2: Processing Piped Input from Another Command

(your_command | dc)

dc can also process data piped to its standard input. This allows you to colorize the output of any command that writes to stdout.

Key Characteristics:

• dc reads data line by line (or in chunks) from stdin.
• It applies colorization to the received data.
• The colorized data is then printed to stdout.
• This mode is useful when you want to take the output of an existing command and pass it through dc for colorization.

Examples:

• Colorizing the output of cat:

  cat myapplication.log | dc

• Colorizing the output of grep:

  grep "ERROR" system.log | dc

• Colorizing a JSON string from echo:

  echo '{"name": "example", "value": 123}' | dc

Understanding dc Behavior in Pipes

It's important to understand how dc behaves when used in command pipelines to avoid confusion:

1. dc your_command [args...] | another_command (Piping from dc when dc wraps a command):

   • dc first executes your_command and colorizes its output.
   • This colorized output (including ANSI escape codes) is then piped to another_command.
   • Example: dc tail -f my.log | grep "ERROR" will pass colorized lines to grep. This might be useful if another_command can handle ANSI codes (like less -R), but often grep would be better used before dc if you want to filter first, then colorize (see Mode 2).

2. dc | another_command (Piping from dc when dc has no command to run):

   • If dc is used as the first command in a pipeline without being given its own command to execute (e.g., dc | grep foo), it defaults to Mode 2 behavior: it will read from its standard input.
   • If stdin is your terminal, dc will wait for you to type something. What you type will be colorized and then passed to another_command.
   • This is why dc | tail -f /path/to/logfile.log does not work as expected for live log monitoring. In this case, dc waits for stdin, and tail -f would attempt to process whatever (if anything) dc outputs, rather than dc processing tail -f's file monitoring output.
   • Correct for live log monitoring: dc tail -f /path/to/logfile.log (Mode 1).

3. your_command | dc | another_command (Piping through dc):

   • your_command sends its output to dc.
   • dc colorizes this output (Mode 2).
   • The colorized output from dc is then piped to another_command.
   • Example: cat my.log | dc | grep "ERROR" (again, grep will operate on colorized text).

General Tip for Piping: If you want to filter or process text before colorization, do it before piping to dc (e.g., grep "ERROR" my.log | dc). If you want to filter or process the colorized text, pipe from dc (e.g., dc tail -f my.log | less -R).