src/help.h

   1 /*
   2  * Helper functions for formatting --help program output.
   3  *
   4  * Copyright © 2021, 2023-2024 Nick Bowler
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef DX_HELP_H_
  21 #define DX_HELP_H_
  22
  23 /*
  24  * On some very old preprocessors (e.g., VAX C) -Dinline= defines inline to 1,
  25  * so when not using a config header detect and work around the problem here.
  26  */
  27 #if !HAVE_CONFIG_H && (inline - 1 == 0)
  28 #  undef inline
  29 #  define inline
  30 #endif
  31
  32 struct option;
  33
  34 /*
  35  * Print an option string describing the short option character (if any),
  36  * the long option name, and the argument name (if applicable).  The argument
  37  * name is localized (if NLS is enabled).  If the string width is more than
  38  * l columns, a newline is printed and 0 is returned.  Otherwise, a newline
  39  * is not printed and the string width (in columns) is returned.
  40  */
  41 int help_print_optstring(const struct option *opt, const char *argname, int l);
  42
  43 /*
  44  * Print an option description with each line indented.  If opt is not NULL,
  45  * then the string is first localized (if NLS is enabled) via pgettext_expr
  46  * with the context set to opt->name.  The first line will be indented by
  47  * i-w spaces (to account for the cursor being in some other column), all
  48  * other lines are indented by i spaces.
  49  *
  50  * The output always ends with a newline, regardless of whether or not the
  51  * input string ends with a newline.
  52  */
  53 void help_print_desc(const struct option *opt, const char *desc, int i, int w);
  54
  55 static inline void help_print_option(const struct option *opt,
  56                                      const char *argname, const char *desc,
  57                                      int w)
  58 {
  59         if (w < 2)
  60                 w = 2;
  61
  62         help_print_desc(opt, desc, w,
  63                         help_print_optstring(opt, argname, w-2));
  64 }
  65
  66 #endif