Example usage:
```bash
cat file | md q
pp | md q       # pp is a command I have which pastes from the clipboard on cygwin, macos and x11.
```
takes a text file (or from the clipboard) adds leading `> ` to it and prints it out.
There is also the w command which textwraps. And commands are chained. So e.g.
```bash
cat file | md w q
```
first text-wraps the input, then blockquotes it. By doing
```bash
pp | md w q | pc
```
I can paste through a pipeline with `md w q` and send the result back to the clipboard.

## Source
```python
#!/usr/bin/env python3
import sys

def main():
  args = sys.argv[1:]
  md = sys.stdin.read()
  for arg in args:
    if arg in actions:
      md = actions[arg](md)
  print(md)

def blockquote(md):
  a = []
  for x in md.splitlines():
    a.append(f"> {x}")
  return "\n".join(a)

import textwrap
def wrap(md):
  t = textwrap.wrap(md)
  return "\n".join(t)

actions = {}
actions['blockquote'] = blockquote
actions['q'] = blockquote
actions['w'] = wrap

if __name__ == "__main__":
  main()
```

## Source of pp and pc
```bash
#!/bin/dash
# pc -- copy to clipboard
if [ -n "$DISPLAY" ]; then # X11
  cat "$@" | xsel -i -b
elif [ -d "/Applications" ]; then # macos
  cat "$@" | pbcopy
elif [ -d "/cygdrive/c/cygwin64" ]; then # cygwin
  cat "$@" > /dev/clipboard
else
  echo "Cannot copy as not gui" > /dev/stderr
fi
```
```bash
#!/bin/dash
# pp - paste
if [ -n "$DISPLAY" ]; then # X11
  paste() { xsel -o -b; }
elif [ -d "/Applications" ]; then # macos
  paste() { pbpaste; }
elif [ -d "/cygdrive/c/cygwin64" ]; then # cygwin
  paste() { cat /dev/clipboard; }
else
  echo "Cannot paste as not gui" > /dev/stderr
fi
if [ -n "$1" ]; then
  paste | tee "$1"
else
  paste
fi
```