adtools/clib2

/*
 * $Id: string_strerror.c,v 1.4 2006-09-17 17:36:42 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * 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.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
 */

#ifndef _STRING_HEADERS_H
#include "string_headers.h"
#endif /* _STRING_HEADERS_H */

/****************************************************************************/

static void
number_to_string(int number,char * string,size_t string_size)
{
    int is_negative = 0;
    char * s = string;
    unsigned int n;
    size_t i,len;
    char c;

    /* We convert the error number into in an unsigned
       integer, so that numbers such as 0x80000000
       can come out of the conversion. */
    if(number < 0)
    {
        is_negative = 1;

        n = (-number);
    }
    else
    {
        n = number;
    }

    /* Convert the error number into a string of digits. */
    len = 0;

    do
    {
        (*s++) = '0' + (n % 10);
        n /= 10;
        len++;
    }
    while(n > 0 && len < string_size-1);

    /* Add the sign, if necessary. */
    if(is_negative && len < string_size-1)
    {
        (*s++) = '-';
        len++;
    }

    (*s) = '\0';

    /* Reverse the string in place. */
    for(i = 0 ; i < len / 2 ; i++)
    {
        c                = string[len-1-i];
        string[len-1-i]    = string[i];
        string[i]        = c;
    }
}

/****************************************************************************/

char *
strerror(int error_number)
{
    static char error_message[80];

    /* NOTE: We are making the assumption that if strerror_r() fails, it
             will fail only because the error code is unknown, and not
             because the size of the supplied buffer is too small. */

    if(strerror_r(error_number,error_message,sizeof(error_message)) != 0)
    {
        char number[20];

        number_to_string(error_number,number,sizeof(number));

        strcpy(error_message,"Unknown error ");
        strcat(error_message,number);
    }

    return(error_message);
}