2.3-InternetRadio/nutos/nut/crt/strtok_r.c

/*--------------------------------------------------------------------------*/
/*                                                                          */
/*  File:           STRTOK_R.C                                              */
/*  Created:        20-September-2002                                       */
/*  Author:         Peter Scandrett                                         */
/*  Description:    Module to provide a reentrant version of the 'C'        */
/*                      function STRTOK.                                    */
/*                                                                          */
/*--------------------------------------------------------------------------*/
/*                                                                          */
/*  Copyright (C) 2002 by ALSTOM Australia Limited. All rights reserved.    */
/*                                                                          */
/*  Redistribution and use in source and binary forms, with or without      */
/*  modification, are permitted provided that the following conditions      */
/*  are met:                                                                */
/*  1.  Redistributions of source code must retain the above copyright      */
/*      notice and this list of conditions.                                 */
/*  2.  Neither the name of ALSTOM Australia Limited nor the names of its   */
/*      contributors may be used to endorse or promote products derived     */
/*      from this software.                                                 */
/*                                                                          */
/*  THIS SOFTWARE IS PROVIDED BY ALSTOM AUSTRALIA LIMITED AND CONTRIBUTORS  */
/*  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT     */
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/*  DAMAGE.                                                                 */
/*                                                                          */
/*--------------------------------------------------------------------------*/

/*
 * $Log$
 * Revision 1.7  2008/02/15 17:13:16  haraldkipp
 * Use configurable constant attribute.
 *
 * Revision 1.6  2006/10/08 16:48:08  haraldkipp
 * Documentation fixed
 *
 * Revision 1.5  2004/07/27 19:28:51  drsung
 * Implementation of strtok_r adjusted to the POSIX 1c standard.
 *
 * Revision 1.4  2003/12/16 22:34:41  drsung
 * Portability issues
 *
 */

#include <stdlib.h>
#include <string.h>

#include "strtok_r.h"

/*!
 * \addtogroup xgCrtMisc
 *
 * The functions strtok_r(), strsep_r() and strsep_rs() are intended as a
 * replacement for the strtok() function. While the strtok() function should
 * be preferred for portability reasons (it conforms to ISO/IEC 9899:1990
 * ("ISO C89")) it may not be able to be used in a multi-threaded environment
 * (that is it is not reentrant). Functions strsep_r() and strsep_rs() can
 * handle empty fields, (i.e. detect fields delimited by two adjacent
 * delimiter characters). Function strsep() first appeared in 4.4BSD.
 */
/*@{*/

/*--------------------------------------------------------------------------*/

static char *end_tok(char **pp_str, const char *p_delim, char *p_sep)
{
    register const char *sp;
    char *p_tok;
    char *p_ch;

    /*  Use a local pointer. */
    p_ch = *pp_str;

    /*  Scan for next deliminator. */
    p_tok = p_ch;
    while (*p_ch != 0) {
        for (sp = p_delim; *sp != 0; sp++) {
            if (*sp == *p_ch) {
                if (p_sep != NULL) {
                    /*  Save terminator. */
                    *p_sep = *p_ch;
                }
                *p_ch++ = 0;
                *pp_str = p_ch;
                return p_tok;
            }
        }
        p_ch++;
    }

    /*  At end of string, so exit, but return last token. */
    *pp_str = p_ch;
    return p_tok;
}

/*--------------------------------------------------------------------------*/

/*!
 * \brief Thread safe variant of strsep.
 *
 * This function is identical in operation to strsep_r(), except it returns the
 * deliminating character.
 */
char *strsep_rs(char **pp_str, const char *p_delim, char *p_sep)
{
    char *p_ch;

    /*  Assume terminator was end of string. */
    if (p_sep != NULL)
        *p_sep = 0;

    /*  Check not passed a NULL. */
    if (pp_str == NULL)
        return NULL;

    /*  Use a local pointer. */
    p_ch = *pp_str;
    if (p_ch == NULL)
        return NULL;

    if (*p_ch == 0)
        return NULL;

    /*  Check a valid delimiter string. */
    if ((p_delim == NULL) || (*p_delim == 0)) {
        *pp_str = NULL;
        return p_ch;
    }
    /*  Scan for next deliminator. */
    return end_tok(pp_str, p_delim, p_sep);
}

/*--------------------------------------------------------------------------*/

/*!
 * \brief Thread safe version of strsep.
 *
 * This function locates, in the string referenced by *str, the first occurrence of
 * any character in the string delim (or the terminating `\\0' character) and
 * replaces it with a `\\0'. The location of the next character after the delimiter
 * character (or NULL, if the end of the string was reached) is stored in *str.
 * The original value of *str is returned.
 *
 * An "empty" field, i.e. one caused by two adjacent delimiter characters, can be
 * detected by comparing the location referenced by the pointer returned in *str
 * to `\\0'.
 *
 * If *str is initially NULL, strsep_r() returns NULL.
 *
 * If delim is NULL or the empty string, strsep_r() returns *str.
 */
char *strsep_r(char **pp_str, const char *p_delim)
{
    return strsep_rs(pp_str, p_delim, NULL);
}

/*--------------------------------------------------------------------------*/
/*!
 * \brief Thread safe version of strtok.
 *
 * This function locates, in the string referenced by *s, the occurrence of
 * any character in the string delim (or the terminating `\\0' character) and
 * replaces them with a `\\0'. The location of the next character after the
 * delimiter character (or NULL, if the end of the string was reached) is
 * stored in *save_ptr. The first character not a delimiter character from
 * the original value of *s is returned.
 *
 * \deprecated This function is supported by avrlibc, which uses different
 *             parameters. It's still available for ICCAVR, but should be
 *             avoided for portability reasons.
 */
#ifdef __IMAGECRAFT__
/* Parse S into tokens separated by characters in DELIM.
   If S is NULL, the saved pointer in SAVE_PTR is used as
   the next starting point.  For example:
    char s[] = "-abc-=-def";
    char *sp;
    x = strtok_r(s, "-", &sp);  // x = "abc", sp = "=-def"
    x = strtok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
    x = strtok_r(NULL, "=", &sp);   // x = NULL
        // s = "abc\\0-def\\0"
*/
char *strtok_r(char *s, const char *delim, char **save_ptr)
{
    char *token;

    if (s == NULL)
        s = *save_ptr;

    /* Scan leading delimiters.  */
    s += strspn(s, delim);
    if (*s == '\0')
        return NULL;

    /* Find the end of the token.  */
    token = s;
    s = strpbrk(token, delim);
    if (s == NULL)
        /* This token finishes the string.  */
        *save_ptr = strchr(token, '\0');
    else {
        /* Terminate the token and make *SAVE_PTR point past it.  */
        *s = '\0';
        *save_ptr = s + 1;
    }
    return token;
}
#endif /*__IMAGECRAFT__ */

/*@}*/

/*-------------------------- end of file STRTOK_R.C ------------------------*/