source: mainline/uspace/app/bdsh/cmds/modules/printf/printf.c

/*
 * Copyright (c) 2012 Alexander Prutkov
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include "config.h"
#include "util.h"
#include "errors.h"
#include "entry.h"
#include "printf.h"
#include "cmds.h"
#include "str.h"

static const char *cmdname = "printf";

/* Dispays help for printf in various levels */
void help_cmd_printf(unsigned int level)
{
        if (level == HELP_SHORT) {
                printf("`%s' prints formatted data.\n", cmdname);
        } else {
                help_cmd_printf(HELP_SHORT);
                printf(
                    "Usage:  %s FORMAT [ARGS ...] \n"
                    "Prints ARGS according to FORMAT. Number of expected arguments in\n"
                    "FORMAT must be equals to the number of ARGS. Currently supported\n"
                    "format flags are:\n",
                    cmdname);
        }

        return;
}

/** Print a formatted data with lib printf.
 *
 * Currently available format flags are:
 * '%d' - integer.
 * '%u' - unsigned integer.
 * '%s' - null-terminated string.
 *
 * @param ch  formatted flag.
 * @param arg string with data to print.
 */
static int print_arg(char32_t ch, const char *arg)
{
        switch (ch) {
        case 'd':
                printf("%d", (int)(strtol(arg, NULL, 10)));
                break;
        case 'u':
                printf("%u", (unsigned int)(strtoul(arg, NULL, 10)));
                break;
        case 's':
                printf("%s", arg);
                break;
        default:
                return CMD_FAILURE;
        }
        return CMD_SUCCESS;
}

/** Process a control character.
 *
 * Currently available characters are:
 * '\n' - new line.
 *
 * @param ch  Control character.
 */
static int process_ctl(char32_t ch)
{
        switch (ch) {
        case 'n':
                printf("\n");
                break;
        default:
                return CMD_FAILURE;
        }
        return CMD_SUCCESS;
}

/** Prints formatted data.
 *
 * Accepted format flags:
 * %d - print an integer
 * %u - print an unsigned integer
 * %s - print a null terminated string
 *
 * Accepted output controls:
 * \n - new line
 */
int cmd_printf(char **argv)
{
        unsigned int argc;
        char *fmt;
        size_t pos, fmt_sz;
        char32_t ch;
        bool esc_flag = false;
        unsigned int carg;     // Current argument

        /* Count the arguments */
        argc = 0;
        while (argv[argc] != NULL)
                argc++;

        if (argc < 2) {
                printf("Usage:  %s FORMAT [ARGS ...] \n", cmdname);
                return CMD_SUCCESS;
        }

        fmt = argv[1];
        fmt_sz = str_size(fmt);
        pos = 0;
        carg = 2;

        while ((ch = str_decode(fmt, &pos, fmt_sz))) {
                switch (ch) {

                case '\\':
                        if (esc_flag)
                                goto emit;
                        esc_flag = true;
                        break;

                case '%':
                        if (esc_flag)
                                goto emit;
                        ch = str_decode(fmt, &pos, fmt_sz);
                        if (!ch) {
                                putchar('%');
                                break;
                        }
                        if (carg == argc) {
                                printf("\nBad parameter number. Aborted.\n");
                                return CMD_FAILURE;
                        }
                        print_arg(ch, argv[carg]);
                        ++carg;
                        break;

                default:
                        if (esc_flag) {
                                process_ctl(ch);
                                esc_flag = false;
                                break;
                        }
                        putuchar(ch);
                        break;

                emit:
                        putuchar(ch);
                        esc_flag = false;
                }
        }

        return CMD_SUCCESS;
}