fish-shell/builtin_set_color.cpp

/** \file builtin_set_color.cpp Functions defining the set_color builtin

Functions used for implementing the set_color builtin.

*/
#include "config.h"

#include "builtin.h"
#include "color.h"
#include "output.h"

#if HAVE_NCURSES_H
#include <ncurses.h>
#elif HAVE_NCURSES_CURSES_H
#include <ncurses/curses.h>
#else
#include <curses.h>
#endif

#if HAVE_TERM_H
#include <term.h>
#elif HAVE_NCURSES_TERM_H
#include <ncurses/term.h>
#endif


/* We know about these buffers */
extern wcstring stdout_buffer, stderr_buffer;

/**
   Error message for invalid path operations
*/
#define BUILTIN_SET_PATH_ERROR L"%ls: Warning: path component %ls may not be valid in %ls.\n"

/**
   Hint for invalid path operation with a colon
*/
#define BUILTIN_SET_PATH_HINT L"%ls: Did you mean 'set %ls $%ls %ls'?\n"

/**
   Error for mismatch between index count and elements
*/
#define BUILTIN_SET_ARG_COUNT L"%ls: The number of variable indexes does not match the number of values\n"

static void print_colors(void)
{
    const wcstring_list_t result = rgb_color_t::named_color_names();
    size_t i;
    for (i=0; i < result.size(); i++)
    {
        stdout_buffer.append(result.at(i));
        stdout_buffer.push_back(L'\n');
    }
}

/* function we set as the output writer */
static std::string builtin_set_color_output;
static int set_color_builtin_outputter(char c)
{
    ASSERT_IS_MAIN_THREAD();
    builtin_set_color_output.push_back(c);
    return 0;
}

/**
   set_color builtin
*/
static int builtin_set_color(parser_t &parser, wchar_t **argv)
{
    /** Variables used for parsing the argument list */
    const struct woption long_options[] =
    {
        { L"background", required_argument, 0, 'b'},
        { L"help", no_argument, 0, 'h' },
        { L"bold", no_argument, 0, 'o' },
        { L"underline", no_argument, 0, 'u' },
        { L"version", no_argument, 0, 'v' },
        { L"print-colors", no_argument, 0, 'c' },
        { 0, 0, 0, 0 }
    };

    const wchar_t *short_options = L"b:hvocu";

    int argc = builtin_count_args(argv);

    /* Some code passes variables to set_color that don't exist, like $fish_user_whatever. As a hack, quietly return failure. */
    if (argc <= 1)
    {
        return EXIT_FAILURE;
    }

    const wchar_t *bgcolor = NULL;
    bool bold = false, underline=false;
    int errret;

    /* Parse options to obtain the requested operation and the modifiers */
    woptind = 0;
    while (1)
    {
        int c = wgetopt_long(argc, argv, short_options, long_options, 0);

        if (c == -1)
        {
            break;
        }

        switch (c)
        {
            case 0:
                break;

            case 'b':
                bgcolor = woptarg;
                break;

            case 'h':
                builtin_print_help(parser, argv[0], stdout_buffer);
                return STATUS_BUILTIN_OK;

            case 'o':
                bold = true;
                break;

            case 'u':
                underline = true;
                break;

            case 'c':
                print_colors();
                return STATUS_BUILTIN_OK;

            case '?':
                return STATUS_BUILTIN_ERROR;
        }
    }

    /* Remaining arguments are foreground color */
    std::vector<rgb_color_t> fgcolors;
    for (; woptind < argc; woptind++)
    {
        rgb_color_t fg = rgb_color_t(argv[woptind]);
        if (fg.is_none() || fg.is_ignore())
        {
            append_format(stderr_buffer, _(L"%ls: Unknown color '%ls'\n"), argv[0], argv[woptind]);
            return STATUS_BUILTIN_ERROR;
        }
        fgcolors.push_back(fg);
    }

    if (fgcolors.empty() && bgcolor == NULL && !bold && !underline)
    {
        append_format(stderr_buffer,
                      _(L"%ls: Expected an argument\n"),
                      argv[0]);
        return STATUS_BUILTIN_ERROR;
    }
    
    // #1323: We may have multiple foreground colors. Choose the best one.
    // If we had no foreground coor, we'll get none(); if we have at least one we expect not-none
    const rgb_color_t fg = best_color(fgcolors, output_get_color_support());
    assert(fgcolors.empty() || !(fg.is_none() || fg.is_ignore()));

    const rgb_color_t bg = rgb_color_t(bgcolor ? bgcolor : L"");
    if (bgcolor && (bg.is_none() || bg.is_ignore()))
    {
        append_format(stderr_buffer, _(L"%ls: Unknown color '%ls'\n"), argv[0], bgcolor);
        return STATUS_BUILTIN_ERROR;
    }

    /* Make sure that the term exists */
    if (cur_term == NULL && setupterm(0, STDOUT_FILENO, &errret) == ERR)
    {
        append_format(stderr_buffer, _(L"%ls: Could not set up terminal\n"), argv[0]);
        return STATUS_BUILTIN_ERROR;
    }

    /*
       Test if we have at least basic support for setting fonts, colors
       and related bits - otherwise just give up...
    */
    if (! exit_attribute_mode)
    {
        return STATUS_BUILTIN_ERROR;
    }

    /* Save old output function so we can restore it */
    int (* const saved_writer_func)(char) = output_get_writer();

    /* Set our output function, which writes to a std::string */
    builtin_set_color_output.clear();
    output_set_writer(set_color_builtin_outputter);

    if (bold)
    {
        if (enter_bold_mode)
            writembs(tparm(enter_bold_mode));
    }

    if (underline)
    {
        if (enter_underline_mode)
            writembs(enter_underline_mode);
    }

    if (bgcolor != NULL)
    {
        if (bg.is_normal())
        {
            write_color(rgb_color_t::black(), false /* not is_fg */);
            writembs(tparm(exit_attribute_mode));
        }
    }

    if (! fg.is_none())
    {
        if (fg.is_normal() || fg.is_reset())
        {
            write_color(rgb_color_t::black(), true /* is_fg */);
            writembs(tparm(exit_attribute_mode));
        }
        else
        {
            write_color(fg, true /* is_fg */);
        }
    }

    if (bgcolor != NULL)
    {
        if (! bg.is_normal() && ! bg.is_reset())
        {
            write_color(bg, false /* not is_fg */);
        }
    }

    /* Restore saved writer function */
    output_set_writer(saved_writer_func);

    /* Output the collected string */
    stdout_buffer.append(str2wcstring(builtin_set_color_output));
    builtin_set_color_output.clear();

    return STATUS_BUILTIN_OK;
}