lib_str.c

lpc2478+ucosII+ucgui源码

*
*               (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);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                              Str_Cat()
*
* Description : Append concatenation string to destination string.
*
* Argument(s) : pdest       Pointer to destination   string to append concatenation  string (see Note #1).
*
*               pstr_cat    Pointer to concatenation string to append to destination string.
*
* Return(s)   : Pointer to destination string, if NO errors (see Note #2).
*
*               Pointer to NULL,               otherwise.
*
* Caller(s)   : Application.
*
* Note(s)     : (1) Destination string buffer size NOT validated; buffer overruns MUST be prevented by caller.
*
*                   (a) Destination buffer size MUST be large enough to accommodate the entire concatenated
*                       string size including the terminating NULL character.
*
*               (2) String concatenation terminates when :
*
*                   (a) Destination/Concatenation string pointer(s) are passed NULL pointers.
*                       (1) No string concatenation performed; NULL pointer returned.
*
*                   (b) Destination string overlaps with NULL address.
*                       (1) No string concatenation performed; NULL pointer returned.
*
*                   (c) Destination/Concatenation string pointer(s) points to NULL.
*                       (1) String buffer(s) overlap with NULL address.
*                       (2) Concatenation string appended into destination string buffer up to but NOT
*                           beyond or including the NULL address; destination string buffer properly
*                           terminated with NULL character.
*
*                   (d) Concatenation string's terminating NULL character found.
*                       (1) Entire concatenation string appended to destination string.
*********************************************************************************************************
*/

CPU_CHAR  *Str_Cat (CPU_CHAR  *pdest,
                    CPU_CHAR  *pstr_cat)
{
    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 (pstr_cat == (CPU_CHAR *)0) {
        return  ((CPU_CHAR *)0);
    }


    pstr = pdest;
    while (( pstr != (CPU_CHAR *)0) &&                          /* Adv to end of cur dest str until NULL ptr ...        */
           (*pstr != (CPU_CHAR  )0)) {                          /* ... or NULL char found..                             */
        pstr++;
    }
    if (pstr == (CPU_CHAR *)0) {                                /* If NULL str overrun, rtn NULL (see Note #2b).        */
        return ((CPU_CHAR *)0);
    }

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

   *pstr = (CPU_CHAR)0;                                         /* Append NULL char (see Note #2c2).                    */


    return (pdest);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                             Str_Cat_N()
*
* Description : Append concatenation string to destination string, up to a maximum number of characters.
*
* Argument(s) : pdest       Pointer to destination   string to append concatenation  string (see Note #1).
*
*               pstr_cat    Pointer to concatenation string to append to destination string.
*
*               len_max     Maximum number of characters to concatenate (see Note #2e).
*
* Return(s)   : Pointer to destination string, if NO errors (see Note #2).
*
*               Pointer to NULL,               otherwise.
*
* Caller(s)   : Application.
*
* Note(s)     : (1) Destination string buffer size NOT validated; buffer overruns MUST be prevented by caller.
*
*                   (a) Destination buffer size MUST be large enough to accommodate the entire concatenated
*                       string size including the terminating NULL character.
*
*               (2) String concatenation terminates when :
*
*                   (a) Destination/Concatenation string pointer(s) are passed NULL pointers.
*                       (1) No string concatenation performed; NULL pointer returned.
*
*                   (b) Destination string overlaps with NULL address.
*                       (1) No string concatenation performed; NULL pointer returned.
*
*                   (c) Destination/Concatenation string pointer(s) points to NULL.
*                       (1) String buffer(s) overlap with NULL address.
*                       (2) Concatenation string appended into destination string buffer up to but NOT
*                           beyond or including the NULL address; destination string buffer properly
*                           terminated with NULL character.
*
*                   (d) Concatenation string's terminating NULL character found.
*                       (1) Entire concatenation string appended to destination string.
*
*                   (e) 'len_max' number of characters concatenated.
*                       (1) 'len_max' number of characters does NOT include the terminating NULL character.
*
*                           See also Note #1a.
*********************************************************************************************************
*/
/*$PAGE*/
CPU_CHAR  *Str_Cat_N (CPU_CHAR    *pdest,
                      CPU_CHAR    *pstr_cat,
                      CPU_SIZE_T   len_max)
{
    CPU_CHAR    *pstr;
    CPU_CHAR    *pstr_next;
    CPU_SIZE_T   len_cat;

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

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


    pstr = pdest;
    while (( pstr != (CPU_CHAR *)0) &&                          /* Adv to end of cur dest str until NULL ptr ...        */
           (*pstr != (CPU_CHAR  )0)) {                          /* ... or NULL char found..                             */
        pstr++;
    }
    if (pstr == (CPU_CHAR *)0) {                                /* If NULL str overrun, rtn NULL (see Note #2b).        */
        return ((CPU_CHAR *)0);
    }

    pstr_next = pstr;
    pstr_next++;
    len_cat   = 0;

    while (( pstr_next != (CPU_CHAR *)0) &&                     /* Cat str until NULL ptr(s)  (see Note #2c)  ...       */
           ( pstr_cat  != (CPU_CHAR *)0) &&
           (*pstr_cat  != (CPU_CHAR  )0) &&                     /* ... or NULL char found     (see Note #2d); ...       */
           ( len_cat   <  (CPU_SIZE_T)len_max)) {               /* ... or max nbr chars cat'd (see Note #2d).           */
       *pstr = *pstr_cat;
        pstr++;
        pstr_next++;
        pstr_cat++;
        len_cat++;
    }

   *pstr = (CPU_CHAR)0;                                         /* Append NULL char (see Note #2c2).                    */


    return (pdest);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                              Str_Cmp()
*
* Description : Determine if two strings are identical.
*
* Argument(s) : p1_str      Pointer to first  string (see Note #1).
*
*               p2_str      Pointer to second string (see Note #1).
*
* Return(s)   : 0,              if strings are identical             (see Notes #2a, #2e, & #2f).
*
*               Negative value, if 'p1_str' is less    than 'p2_str' (see Notes #2b, #2g, & #2d).
*
*               Positive value, if 'p1_str' is greater than 'p2_str' (see Notes #2c, #2h, & #2d).
*
* Caller(s)   : Application.
*
* Note(s)     : (1) String buffers NOT modified.
*
*               (2) String comparison terminates when :
*
*                   (a) BOTH string pointer(s) are passed NULL pointers.
*                       (1) NULL strings identical; return 0.
*
*                   (b) 'p1_str' passed a NULL pointer.
*                       (1) Return negative value of character pointed to by 'p2_str'.
*
*                   (c) 'p2_str' passed a NULL pointer.
*                       (1) Return positive value of character pointed to by 'p1_str'.
*
*                   (d) Non-matching characters found.
*                       (1) Return signed-integer difference of the character pointed to by 'p2_str'
*                           from the character pointed to by 'p1_str'.
*
*                   (e) Terminating NULL character found in both strings.
*                       (1) Strings identical; return 0.
*                       (2) Only one NULL character test required in conditional since previous condition
*                           tested character equality.
*