src/cli/opt_usage.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "cli.h"
   9 #include "str.h"
  10
  11 static int print_spec_name(git_str *out, const cli_opt_spec *spec)
  12 {
  13         if (spec->type == CLI_OPT_TYPE_VALUE && spec->alias &&
  14             !(spec->usage & CLI_OPT_USAGE_VALUE_OPTIONAL) &&
  15             !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  16                 return git_str_printf(out, "-%c <%s>", spec->alias, spec->value_name);
  17         if (spec->type == CLI_OPT_TYPE_VALUE && spec->alias &&
  18             !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  19                 return git_str_printf(out, "-%c [<%s>]", spec->alias, spec->value_name);
  20         if (spec->type == CLI_OPT_TYPE_VALUE &&
  21             !(spec->usage & CLI_OPT_USAGE_VALUE_OPTIONAL))
  22                 return git_str_printf(out, "--%s[=<%s>]", spec->name, spec->value_name);
  23         if (spec->type == CLI_OPT_TYPE_VALUE)
  24                 return git_str_printf(out, "--%s=<%s>", spec->name, spec->value_name);
  25         if (spec->type == CLI_OPT_TYPE_ARG)
  26                 return git_str_printf(out, "<%s>", spec->value_name);
  27         if (spec->type == CLI_OPT_TYPE_ARGS)
  28                 return git_str_printf(out, "<%s>...", spec->value_name);
  29         if (spec->type == CLI_OPT_TYPE_LITERAL)
  30                 return git_str_printf(out, "--");
  31         if (spec->alias && !(spec->usage & CLI_OPT_USAGE_SHOW_LONG))
  32                 return git_str_printf(out, "-%c", spec->alias);
  33         if (spec->name)
  34                 return git_str_printf(out, "--%s", spec->name);
  35
  36         GIT_ASSERT(0);
  37 }
  38
  39 /*
  40  * This is similar to adopt's function, but modified to understand
  41  * that we have a command ("git") and a "subcommand" ("checkout").
  42  * It also understands a terminal's line length and wrap appropriately,
  43  * using a `git_str` for storage.
  44  */
  45 int cli_opt_usage_fprint(
  46         FILE *file,
  47         const char *command,
  48         const char *subcommand,
  49         const cli_opt_spec specs[])
  50 {
  51         git_str usage = GIT_BUF_INIT, opt = GIT_BUF_INIT;
  52         const cli_opt_spec *spec;
  53         size_t i, prefixlen, linelen;
  54         bool choice = false, next_choice = false, optional = false;
  55         int error;
  56
  57         /* TODO: query actual console width. */
  58         int console_width = 80;
  59
  60         if ((error = git_str_printf(&usage, "usage: %s", command)) < 0)
  61                 goto done;
  62
  63         if (subcommand &&
  64             (error = git_str_printf(&usage, " %s", subcommand)) < 0)
  65                 goto done;
  66
  67         linelen = git_str_len(&usage);
  68         prefixlen = linelen + 1;
  69
  70         for (spec = specs; spec->type; ++spec) {
  71                 if (!choice)
  72                         optional = !(spec->usage & CLI_OPT_USAGE_REQUIRED);
  73
  74                 next_choice = !!((spec + 1)->usage & CLI_OPT_USAGE_CHOICE);
  75
  76                 if (spec->usage & CLI_OPT_USAGE_HIDDEN)
  77                         continue;
  78
  79                 if (choice)
  80                         git_str_putc(&opt, '|');
  81                 else
  82                         git_str_clear(&opt);
  83
  84                 if (optional && !choice)
  85                         git_str_putc(&opt, '[');
  86                 if (!optional && !choice && next_choice)
  87                         git_str_putc(&opt, '(');
  88
  89                 if ((error = print_spec_name(&opt, spec)) < 0)
  90                         goto done;
  91
  92                 if (!optional && choice && !next_choice)
  93                         git_str_putc(&opt, ')');
  94                 else if (optional && !next_choice)
  95                         git_str_putc(&opt, ']');
  96
  97                 if ((choice = next_choice))
  98                         continue;
  99
 100                 if (git_str_oom(&opt)) {
 101                         error = -1;
 102                         goto done;
 103                 }
 104
 105                 if (linelen > prefixlen &&
 106                     console_width > 0 &&
 107                     linelen + git_str_len(&opt) + 1 > (size_t)console_width) {
 108                         git_str_putc(&usage, '\n');
 109
 110                         for (i = 0; i < prefixlen; i++)
 111                                 git_str_putc(&usage, ' ');
 112
 113                         linelen = prefixlen;
 114                 } else {
 115                         git_str_putc(&usage, ' ');
 116                         linelen += git_str_len(&opt) + 1;
 117                 }
 118
 119                 git_str_puts(&usage, git_str_cstr(&opt));
 120
 121                 if (git_str_oom(&usage)) {
 122                         error = -1;
 123                         goto done;
 124                 }
 125         }
 126
 127         error = fprintf(file, "%s\n", git_str_cstr(&usage));
 128
 129 done:
 130         error = (error < 0) ? -1 : 0;
 131
 132         git_str_dispose(&usage);
 133         git_str_dispose(&opt);
 134         return error;
 135 }
 136
 137 int cli_opt_usage_error(
 138         const char *subcommand,
 139         const cli_opt_spec specs[],
 140         const cli_opt *invalid_opt)
 141 {
 142         cli_opt_status_fprint(stderr, PROGRAM_NAME, invalid_opt);
 143         cli_opt_usage_fprint(stderr, PROGRAM_NAME, subcommand, specs);
 144         return CLI_EXIT_USAGE;
 145 }
 146
 147 int cli_opt_help_fprint(
 148         FILE *file,
 149         const cli_opt_spec specs[])
 150 {
 151         git_str help = GIT_BUF_INIT;
 152         const cli_opt_spec *spec;
 153         int error = 0;
 154
 155         /* Display required arguments first */
 156         for (spec = specs; spec->type; ++spec) {
 157                 if (! (spec->usage & CLI_OPT_USAGE_REQUIRED) ||
 158                     (spec->usage & CLI_OPT_USAGE_HIDDEN))
 159                         continue;
 160
 161                 git_str_printf(&help, "    ");
 162
 163                 if ((error = print_spec_name(&help, spec)) < 0)
 164                         goto done;
 165
 166                 git_str_printf(&help, ": %s\n", spec->help);
 167         }
 168
 169         /* Display the remaining arguments */
 170         for (spec = specs; spec->type; ++spec) {
 171                 if ((spec->usage & CLI_OPT_USAGE_REQUIRED) ||
 172                     (spec->usage & CLI_OPT_USAGE_HIDDEN))
 173                         continue;
 174
 175                 git_str_printf(&help, "    ");
 176
 177                 if ((error = print_spec_name(&help, spec)) < 0)
 178                         goto done;
 179
 180                 git_str_printf(&help, ": %s\n", spec->help);
 181
 182         }
 183
 184         if (git_str_oom(&help) ||
 185             p_write(fileno(file), help.ptr, help.size) < 0)
 186                 error = -1;
 187
 188 done:
 189         error = (error < 0) ? -1 : 0;
 190
 191         git_str_dispose(&help);
 192         return error;
 193 }
 194