Standalone generation script

zshgencomp

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+#!/usr/bin/env python
+# -*- coding: UTF-8 -*-
+
+# Parse getopt-style help texts for options
+# and generate zsh(1) completion function.
+# http://github.com/RobSis/zsh-completion-generator
+
+import os
+import sys
+import re
+import argparse
+import subprocess
+from string import Template
+
+
+URL = 'http://github.com/RobSis/zsh-completion-generator'
+STRIP_CHARS = " \t\n,="
+HELP_MSG = """
+Parse getopt-style help texts for options
+and generate zsh(1) completion function.
+http://github.com/RobSis/zsh-completion-generator
+
+Usage:
+    zshgencomp help                 Show this page.
+    zshgencomp COMMAND [OPTIONS]    Generate zsh completion.
+Options:
+    -c HELP_COMMAND           Run custom help command (default: --help).
+
+The completions will be written to STDOUT.
+Direct it into a file instead and place it into any
+directory in your $FPATH to get nice zsh completion.
+
+Examples:
+    zshgencomp ack
+    zshgencomp vim -c "-h"
+"""
+
+COMPLETE_FUNCTION_TEMPLATE = """
+#compdef $program_name
+
+# zsh completions for '$program_name'
+# automatically generated with $url
+local arguments
+
+arguments=(
+$argument_list
+    '*:filename:_files'
+)
+
+_arguments -s $arguments
+"""
+
+ARGUMENT_TEMPLATE = """    {$opts}'[$description]$style'"""
+SINGLE_ARGUMENT_TEMPLATE = """    '$opt[$description]$style'"""
+
+
+def cut_option(line):
+    """
+    Cuts out the first option (short or long) and its argument.
+    """
+    # TODO: dare to make it regex-free?
+    newline = line.strip(STRIP_CHARS)
+    opt = re.findall(r'^(-[a-zA-Z0-9\-]+(?:[\[\ =][^\-\ ][a-zA-Z\<\>\[\|\:\]\-\_\?#]*\]?)?)', line)
+    if len(opt) > 0:
+        newline = line.replace(opt[0], "", 1).strip(STRIP_CHARS)
+        # return without parameter
+        return newline, re.split('[\ \[=]', opt[0])[0]
+    else:
+        return newline, None
+
+
+def parse_options(help_text):
+    """
+    Parses the options line by line.
+    When description is missing and options are missing on
+    consecutive line, link them together.
+    """
+    all_options = []
+    previous_description_missing = False
+    for line in help_text:
+        line = line.strip(STRIP_CHARS)
+        if re.match(r'^--?[a-zA-Z0-9]+', line) != None:  # starts with option
+            previous_description_missing = False
+            options = []
+            while True:
+                line, opt = cut_option(line)
+                if opt == None:
+                    break
+
+                options.append(opt)
+
+            if (len(line) == 0):
+                previous_description_missing = True
+
+            options.append(line)
+            all_options.append(options)
+        elif previous_description_missing:
+            all_options[-1][-1] = line
+            previous_description_missing = False
+
+    return all_options
+
+
+def _escape(line):
+    """
+    Escape the syntax-breaking characters.
+    """
+    line = line.replace('[','\[').replace(']','\]')
+    line = re.sub('\'', '', line)  # ' is unescapable afaik
+    return line
+
+
+def generate_argument_list(options):
+    """
+    Generate list of arguments from the template.
+    """
+    argument_list = []
+    for opts in options:
+        model = {}
+        # remove unescapable chars.
+
+        model['description'] = _escape(opts[-1])
+        model['style'] = ""
+        if (len(opts) > 2):
+            model['opts'] = ",".join(opts[:-1])
+            argument_list.append(Template(ARGUMENT_TEMPLATE).safe_substitute(model))
+        elif (len(opts) == 2):
+            model['opt'] = opts[0]
+            argument_list.append(Template(SINGLE_ARGUMENT_TEMPLATE).safe_substitute(model))
+        else:
+            pass
+
+    return "\n".join(argument_list)
+
+
+def generate_completion_function(options, program_name):
+    """
+    Generate completion function from the template.
+    """
+    model = {}
+    model['program_name'] = program_name
+    model['argument_list'] = generate_argument_list(options)
+    model['url'] = URL
+    return Template(COMPLETE_FUNCTION_TEMPLATE).safe_substitute(model).strip()
+
+def determine_command_options(command_line_args):
+    """
+    Determines and runs appropiate gencomp command.
+    (For now there are only 2)
+    """
+    primary_command = command_line_args[0]
+    if primary_command == "help" or primary_command == "--help":
+        print HELP_MSG
+    else:
+        help_option = "--help"
+        if len(command_line_args) > 1:
+            help_option = parse_custom_help(command_line_args[1:])
+        help_command = [primary_command, help_option]
+        try:
+            help_output = subprocess.check_output(help_command)
+        except subprocess.CalledProcessError:
+            print "Error:"
+            print "Your help option is not supported for this command."
+            sys.exit(1)
+        except:
+            print "Unknown command."
+            sys.exit(1)
+        options = parse_options(help_output.splitlines())
+        print generate_completion_function(options, primary_command)
+
+def parse_custom_help(remaining_options):
+    """
+    Parses the custom help option (e.g. '-h') and
+    returns it, returns '--help' if option is invalid.
+    """
+
+    if len(remaining_options) != 2:
+        return "--help"
+    elif remaining_options[0] != '-c':
+        return "--help"
+    else:
+        return remaining_options[1]
+
+if __name__ == "__main__":
+    if len(sys.argv) > 1:
+        determine_command_options(sys.argv[1:])
+    else:
+        print HELP_MSG