lib_str.c

官方的UCOSii的移植文件

/*
*********************************************************************************************************
*                                               uC/LIB
*                                       CUSTOM LIBRARY MODULES
*
*                          (c) Copyright 2004-2007; Micrium, Inc.; Weston, FL
*
*               All rights reserved.  Protected by international copyright laws.
*
*               uC/LIB is provided in source form for FREE evaluation, for educational
*               use or peaceful research.  If you plan on using uC/LIB in a commercial
*               product you need to contact Micrium to properly license its use in your
*               product.  We provide ALL the source code for your convenience and to
*               help you experience uC/LIB.  The fact that the source code is provided
*               does NOT mean that you can use it without paying a licensing fee.
*
*               Knowledge of the source code may NOT be used to develop a similar product.
*
*               Please help us continue to provide the Embedded community with the finest
*               software available.  Your honesty is greatly appreciated.
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*
*                                       ASCII STRING MANAGEMENT
*
* Filename      : lib_str.c
* Version       : V1.24
* Programmer(s) : ITJ
*                 JDH
*********************************************************************************************************
* Note(s)       : (1) NO compiler-supplied standard library functions are used in library or product software.
*
*                     (a) ALL standard library functions are implemented in the custom library modules :
*
*                         (1) \<Custom Library Directory>\lib*.*
*
*                         (2) \<Custom Library Directory>\Ports\<cpu>\<compiler>\lib*_a.*
*
*                               where
*                                       <Custom Library Directory>      directory path for custom library software
*                                       <cpu>                           directory name for specific processor (CPU)
*                                       <compiler>                      directory name for specific compiler
*
*                     (b) Product-specific library functions are implemented in individual products.
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                            INCLUDE FILES
*********************************************************************************************************
*/

#define    LIB_STR_MODULE
#include  <lib_str.h>


/*$PAGE*/
/*
*********************************************************************************************************
*                                            LOCAL DEFINES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                           LOCAL CONSTANTS
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                          LOCAL DATA TYPES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                            LOCAL TABLES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                       LOCAL GLOBAL VARIABLES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                      LOCAL FUNCTION PROTOTYPES
*********************************************************************************************************
*/


/*
*********************************************************************************************************
*                                     LOCAL CONFIGURATION ERRORS
*********************************************************************************************************
*/


/*$PAGE*/
/*
*********************************************************************************************************
*                                              Str_Len()
*
* Description : Calculate length of a string.
*
* Argument(s) : pstr        Pointer to string (see Note #1).
*
* Return(s)   : Length of string; number of characters in string before terminating NULL character.
*
* Caller(s)   : various.
*
* Note(s)     : (1) String buffer NOT modified.
*
*               (2) String length calculation terminates when :
*
*                   (a) String pointer points to NULL.
*                       (1) String buffer overlaps with NULL address.
*                       (2) String length calculated for string up to but NOT beyond or including
*                           the NULL address.
*
*                   (b) Terminating NULL character found.
*                       (1) String length calculated for string up to but NOT           including
*                           the NULL character.
*********************************************************************************************************
*/

CPU_SIZE_T  Str_Len (CPU_CHAR  *pstr)
{
    CPU_SIZE_T  len;


    len = 0;
    while (( pstr != (CPU_CHAR *)0) &&                          /* Calc str len until NULL ptr (see Note #2a) ...       */
           (*pstr != (CPU_CHAR  )0)) {                          /* ... or NULL char found      (see Note #2b).          */
        len++;
        pstr++;
    }

    return (len);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                             Str_Copy()
*
* Description : Copy source string to destination string buffer.
*
* Argument(s) : pdest       Pointer to destination string buffer to receive source string copy (see Note #1).
*
*               psrc        Pointer to source      string to copy into destination string buffer.
*
* Return(s)   : Pointer to destination string, if NO errors (see Note #2).
*
*               Pointer to NULL,               otherwise.
*
* Caller(s)   : various.
*
* Note(s)     : (1) Destination buffer size NOT validated; buffer overruns MUST be prevented by caller.
*
*                   (a) Destination buffer size MUST be large enough to accommodate the entire source 
*                       string size including the terminating NULL character.
*
*               (2) String copy terminates when :
*
*                   (a) Destination/Source string pointer(s) are passed NULL pointers.
*                       (1) No string copy performed; NULL pointer returned.
*
*                   (b) Destination/Source string pointer(s) points to NULL.
*                       (1) String buffer(s) overlap with NULL address.
*                       (2) Source string copied into destination string buffer up to but NOT beyond or
*                           including the NULL address; destination string buffer properly terminated
*                           with NULL character.
*
*                   (c) Source string's terminating NULL character found.
*                       (1) Entire source string copied into destination string buffer.
*********************************************************************************************************
*/

CPU_CHAR  *Str_Copy (CPU_CHAR  *pdest,
                     CPU_CHAR  *psrc)
{
    CPU_CHAR  *pstr;
    CPU_CHAR  *pstr_next;

                                                                /* Rtn NULL if str ptr(s) NULL (see Note #2a).          */
    if (pdest == (CPU_CHAR *)0) {
        return  ((CPU_CHAR *)0);
    }
    if (psrc  == (CPU_CHAR *)0) {
        return  ((CPU_CHAR *)0);
    }


    pstr      = pdest;
    pstr_next = pstr;
    pstr_next++;
    while (( pstr_next != (CPU_CHAR *)0) &&                     /* Copy str until NULL ptr(s) (see Note #2b) ...        */
           ( psrc      != (CPU_CHAR *)0) &&
           (*psrc      != (CPU_CHAR  )0)) {                     /* ... or NULL char found     (see Note #2c).           */
       *pstr = *psrc;
        pstr++;
        pstr_next++;
        psrc++;
    }

   *pstr = (CPU_CHAR)0;                                         /* Append NULL char (see Note #2b2).                    */


    return (pdest);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                            Str_Copy_N()
*
* Description : Copy source string to destination string buffer, up to a maximum number of characters.
*
* Argument(s) : pdest       Pointer to destination string buffer to receive source string copy (see Note #1).
*
*               psrc        Pointer to source      string to copy into destination string buffer.
*
*               len_max     Maximum number of characters to copy (see Note #2d).
*
* Return(s)   : Pointer to destination string, if NO errors (see Note #2).
*
*               Pointer to NULL,               otherwise.
*
* Caller(s)   : various.
*
* Note(s)     : (1) Destination buffer size NOT validated; buffer overruns MUST be prevented by caller.
*
*                   (a) Destination buffer size MUST be large enough to accommodate the entire source 
*                       string size including the terminating NULL character.
*
*               (2) String copy terminates when :
*
*                   (a) Destination/Source string pointer(s) are passed NULL pointers.
*                       (1) No string copy performed; NULL pointer returned.
*
*                   (b) Destination/Source string pointer(s) points to NULL.
*                       (1) String buffer(s) overlap with NULL address.
*                       (2) Source string copied into destination string buffer up to but NOT beyond or
*                           including the NULL address; destination string buffer properly terminated
*                           with NULL character.
*
*                   (c) Source string's terminating NULL character found.
*                       (1) Entire source string copied into destination string buffer.
*
*                   (d) 'len_max' number of characters copied.
*                       (1) 'len_max' number of characters does NOT include the terminating NULL character.
*
*                           See also Note #1a.
*********************************************************************************************************
*/

CPU_CHAR  *Str_Copy_N (CPU_CHAR    *pdest,
                       CPU_CHAR    *psrc,
                       CPU_SIZE_T   len_max)
{
    CPU_CHAR    *pstr;
    CPU_CHAR    *pstr_next;
    CPU_SIZE_T   len_copy;

                                                                /* Rtn NULL if str ptr(s) NULL      (see Note #2a).     */
    if (pdest == (CPU_CHAR *)0) {
        return  ((CPU_CHAR *)0);
    }
    if (psrc  == (CPU_CHAR *)0) {
        return  ((CPU_CHAR *)0);
    }

    if (len_max == (CPU_SIZE_T)0) {                             /* Rtn NULL if copy len equals zero (see Note #2d).     */
        return  ((CPU_CHAR *)0);
    }


    pstr      = pdest;
    pstr_next = pstr;
    pstr_next++;
    len_copy  = 0;

    while (( pstr_next != (CPU_CHAR *)0) &&                     /* Copy str until NULL ptr(s)  (see Note #2b)  ...      */
           ( psrc      != (CPU_CHAR *)0) &&
           (*psrc      != (CPU_CHAR  )0) &&                     /* ... or NULL char found      (see Note #2c); ...      */
           ( len_copy  <  (CPU_SIZE_T)len_max)) {               /* ... or max nbr chars copied (see Note #2d).          */
       *pstr = *psrc;
        pstr++;
        pstr_next++;
        psrc++;
        len_copy++;
    }

   *pstr = (CPU_CHAR)0;                                         /* Append NULL char (see Note #2b2).                    */


    return (pdest);