thodg/libgit2/src/cli/opt_usage.c

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• Hash : 8526cbd5
  Author :
  Date : 2021-11-26T09:37:29
  

  opt: use a custom function to print usage Our argument parser (https://github.com/ethomson/adopt) includes a function to print a usage message based on the allowed options. Omit this and use a cutom function that understands that we have subcommands ("checkout", "revert", etc) that each have their own options.

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• src/cli/opt_usage.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "cli.h"
  #include "str.h"
  
  static int print_spec_name(git_str *out, const cli_opt_spec *spec)
  {
  	if (spec->type == CLI_OPT_TYPE_VALUE && spec->alias &&
  	    !(spec->usage & CLI_OPT_USAGE_VALUE_OPTIONAL) &&
  	    !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  		return git_str_printf(out, "-%c <%s>", spec->alias, spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_VALUE && spec->alias &&
  	    !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  		return git_str_printf(out, "-%c [<%s>]", spec->alias, spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_VALUE &&
  	    !(spec->usage & CLI_OPT_USAGE_VALUE_OPTIONAL))
  		return git_str_printf(out, "--%s[=<%s>]", spec->name, spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_VALUE)
  		return git_str_printf(out, "--%s=<%s>", spec->name, spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_ARG)
  		return git_str_printf(out, "<%s>", spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_ARGS)
  		return git_str_printf(out, "<%s>...", spec->value_name);
  	if (spec->type == CLI_OPT_TYPE_LITERAL)
  		return git_str_printf(out, "--");
  	if (spec->alias && !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  		return git_str_printf(out, "-%c", spec->alias);
  	if (spec->name)
  		return git_str_printf(out, "--%s", spec->name);
  
  	GIT_ASSERT(0);
  }
  
  /*
   * This is similar to adopt's function, but modified to understand
   * that we have a command ("git") and a "subcommand" ("checkout").
   * It also understands a terminal's line length and wrap appropriately,
   * using a `git_str` for storage.
   */
  int cli_opt_usage_fprint(
  	FILE *file,
  	const char *command,
  	const char *subcommand,
  	const cli_opt_spec specs[])
  {
  	git_str usage = GIT_BUF_INIT, opt = GIT_BUF_INIT;
  	const cli_opt_spec *spec;
  	size_t i, prefixlen, linelen;
  	bool choice = false, next_choice = false, optional = false;
  	int error;
  
  	/* TODO: query actual console width. */
  	int console_width = 80;
  
  	if ((error = git_str_printf(&usage, "usage: %s", command)) < 0)
  		goto done;
  
  	if (subcommand &&
  	    (error = git_str_printf(&usage, " %s", subcommand)) < 0)
  		goto done;
  
  	linelen = git_str_len(&usage);
  	prefixlen = linelen + 1;
  
  	for (spec = specs; spec->type; ++spec) {
  		if (!choice)
  			optional = !(spec->usage & CLI_OPT_USAGE_REQUIRED);
  
  		next_choice = !!((spec + 1)->usage & CLI_OPT_USAGE_CHOICE);
  
  		if (spec->usage & CLI_OPT_USAGE_HIDDEN)
  			continue;
  
  		if (choice)
  			git_str_putc(&opt, '|');
  		else
  			git_str_clear(&opt);
  
  		if (optional && !choice)
  			git_str_putc(&opt, '[');
  		if (!optional && !choice && next_choice)
  			git_str_putc(&opt, '(');
  
  		if ((error = print_spec_name(&opt, spec)) < 0)
  			goto done;
  
  		if (!optional && choice && !next_choice)
  			git_str_putc(&opt, ')');
  		else if (optional && !next_choice)
  			git_str_putc(&opt, ']');
  
  		if ((choice = next_choice))
  			continue;
  
  		if (git_str_oom(&opt)) {
  			error = -1;
  			goto done;
  		}
  
  		if (linelen > prefixlen &&
  		    console_width > 0 &&
  		    linelen + git_str_len(&opt) + 1 > (size_t)console_width) {
  			git_str_putc(&usage, '\n');
  
  			for (i = 0; i < prefixlen; i++)
  				git_str_putc(&usage, ' ');
  
  			linelen = prefixlen;
  		} else {
  			git_str_putc(&usage, ' ');
  			linelen += git_str_len(&opt) + 1;
  		}
  
  		git_str_puts(&usage, git_str_cstr(&opt));
  
  		if (git_str_oom(&usage)) {
  			error = -1;
  			goto done;
  		}
  	}
  
  	error = fprintf(file, "%s\n", git_str_cstr(&usage));
  
  done:
  	error = (error < 0) ? -1 : 0;
  
  	git_str_dispose(&usage);
  	git_str_dispose(&opt);
  	return error;
  }
  
  int cli_opt_usage_error(
  	const char *subcommand,
  	const cli_opt_spec specs[],
  	const cli_opt *invalid_opt)
  {
  	cli_opt_status_fprint(stderr, PROGRAM_NAME, invalid_opt);
  	cli_opt_usage_fprint(stderr, PROGRAM_NAME, subcommand, specs);
  	return CLI_EXIT_USAGE;
  }
  
  int cli_opt_help_fprint(
  	FILE *file,
  	const cli_opt_spec specs[])
  {
  	git_str help = GIT_BUF_INIT;
  	const cli_opt_spec *spec;
  	int error;
  
  	/* Display required arguments first */
  	for (spec = specs; spec->type; ++spec) {
  		if (! (spec->usage & CLI_OPT_USAGE_REQUIRED) ||
  		    (spec->usage & CLI_OPT_USAGE_HIDDEN))
  			continue;
  
  		git_str_printf(&help, "    ");
  
  		if ((error = print_spec_name(&help, spec)) < 0)
  			goto done;
  
  		git_str_printf(&help, ": %s\n", spec->help);
  	}
  
  	/* Display the remaining arguments */
  	for (spec = specs; spec->type; ++spec) {
  		if ((spec->usage & CLI_OPT_USAGE_REQUIRED) ||
  		    (spec->usage & CLI_OPT_USAGE_HIDDEN))
  			continue;
  
  		git_str_printf(&help, "    ");
  
  		if ((error = print_spec_name(&help, spec)) < 0)
  			goto done;
  
  		git_str_printf(&help, ": %s\n", spec->help);
  
  	}
  
  	if (git_str_oom(&help) ||
  	    p_write(fileno(file), help.ptr, help.size) < 0)
  		error = -1;
  
  done:
  	error = (error < 0) ? -1 : 0;
  
  	git_str_dispose(&help);
  	return error;
  }
  
  

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