lib_str.c

UCOS-III

    cmp_val = Str_CmpIgnoreCase_N(p1_str,
                                  p2_str,
                                  DEF_INT_CPU_U_MAX_VAL);

    return (cmp_val);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                        Str_CmpIgnoreCase_N()
*
* Description : Determine if two strings are identical for up to a maximum number of characters,
*                   ignoring case.
*
* Argument(s) : p1_str      Pointer to first  string (see Note #1).
*
*               p2_str      Pointer to second string (see Note #1).
*
*               len_max     Maximum number of characters to compare  (see Note  #3d).
*
* Return(s)   : 0,              if strings are identical             (see Notes #3a1A, #3a2A, #3b, & #3d).
*
*               Negative value, if 'p1_str' is less    than 'p2_str' (see Notes #3a1B1, #3a2B1, & #3c).
*
*               Positive value, if 'p1_str' is greater than 'p2_str' (see Notes #3a1B2, #3a2B2, & #3c).
*
*               See also Note #2b.
*
* Caller(s)   : Application.
*
* Note(s)     : (1) String buffers NOT modified.
*
*               (2) (a) IEEE Std 1003.1, 2004 Edition, Section 'strncasecmp() : DESCRIPTION' states that :
*
*                       (1) (A) "The strncasecmp() function shall compare ... the string pointed to by 's1' 
*                                ('p1_str') to the string pointed to by 's2' ('p2_str')" ...
*                           (B) "ignoring differences in case"                           ...
*                           (C)  but "not more than 'n' ('len_max') bytes" of either string.
*
*                       (2) "strncasecmp() shall behave as if the strings had been converted to lowercase
*                            and then a byte comparison performed."
*
*                   (b) (1) IEEE Std 1003.1, 2004 Edition, Section 'strncasecmp() : RETURN VALUE' states that
*                          "upon successful completion, strncasecmp() shall return an integer greater than,
*                           equal to, or less than 0".
*
*                       (2) IEEE Std 1003.1, 2004 Edition, Section 'strcmp() : DESCRIPTION' adds that "the
*                           sign of a non-zero return value shall be determined by the sign of the difference
*                           between the values of the first pair of bytes ... that differ in the strings
*                           being compared".
*
*               (3) String comparison terminates when :
*
*                   (a) (1) (A) BOTH string pointer(s) are passed NULL pointers.
*                               (1) NULL strings identical; 0 returned.
*
*                           (B) (1) 'p1_str' passed a NULL pointer.
*                                   (a) Return negative value of character pointed to by 'p2_str', converted
*                                       to lower case (see Note #2a2).
*
*                               (2) 'p2_str' passed a NULL pointer.
*                                   (a) Return positive value of character pointed to by 'p1_str', converted
*                                       to lower case (see Note #2a2).
*
*                       (2) (A) BOTH strings point to NULL.
*                               (1) Strings overlap with NULL address.
*                               (2) Strings identical up to but NOT beyond or including the NULL address;
*                                   0 returned.
*
*                           (B) (1) 'p1_str_cmp_next' points to NULL.
*                                   (a) 'p1_str' overlaps with NULL address.
*                                   (b) Strings compared up to but NOT beyond or including the NULL address.
*                                   (c) Return negative value of character pointed to by 'p2_str_cmp_next',
*                                       converted to lower case (see Note #2a2).
*
*                               (2) 'p2_str_cmp_next' points to NULL.
*                                   (a) 'p2_str' overlaps with NULL address.
*                                   (b) Strings compared up to but NOT beyond or including the NULL address.
*                                   (c) Return positive value of character pointed to by 'p1_str_cmp_next',
*                                       converted to lower case (see Note #2a2).
*
*                   (b) Terminating NULL character found in both strings.
*                       (1) Strings identical; 0 returned.
*                       (2) Only one NULL character test required in conditional since previous condition
*                           tested character equality.
*
*                   (c) Non-matching characters found.
*                       (1) Return signed-integer difference of the character pointed to by 'p2_str',
*                           converted to lower case, from the character pointed to by 'p1_str', converted
*                           to lower case.
*
*                   (d) (1) 'len_max' passed a zero length.
*                           (A) Zero-length strings identical; 0 returned.
*
*                       (2) First 'len_max' number of characters identical.
*                           (A) Strings identical; 0 returned.
*
*                       See also Note #2a1C.
*$PAGE*
*               (4) Since 16-bit signed arithmetic is performed to calculate a non-identical comparison
*                   return value, 'CPU_CHAR' native data type size MUST be 8-bit.
*********************************************************************************************************
*/

CPU_INT16S  Str_CmpIgnoreCase_N (const  CPU_CHAR    *p1_str,
                                 const  CPU_CHAR    *p2_str,
                                        CPU_SIZE_T   len_max)
{
    const  CPU_CHAR    *p1_str_cmp;
    const  CPU_CHAR    *p2_str_cmp;
    const  CPU_CHAR    *p1_str_cmp_next;
    const  CPU_CHAR    *p2_str_cmp_next;
           CPU_CHAR     char_1;
           CPU_CHAR     char_2;
           CPU_INT16S   cmp_val;
           CPU_SIZE_T   cmp_len;


    if (len_max < 1) {                                          /* If cmp len = 0,        rtn 0       (see Note #3d1A). */
        return (0);
    }

    if (p1_str == (const CPU_CHAR *)0) {
        if (p2_str == (const CPU_CHAR *)0) {
            return (0);                                         /* If BOTH str ptrs NULL, rtn 0       (see Note #3a1A). */
        }
        char_2  =  ASCII_ToLower(*p2_str);
        cmp_val = (CPU_INT16S)0 - (CPU_INT16S)char_2;
        return (cmp_val);                                       /* If p1_str NULL, rtn neg p2_str val (see Note #3a1B1).*/
    }
    if (p2_str == (const CPU_CHAR *)0) {
        char_1  =  ASCII_ToLower(*p1_str);
        cmp_val = (CPU_INT16S)char_1;
        return (cmp_val);                                       /* If p2_str NULL, rtn pos p1_str val (see Note #3a1B2).*/
    }


    p1_str_cmp      = p1_str;
    p2_str_cmp      = p2_str;
    p1_str_cmp_next = p1_str_cmp;
    p2_str_cmp_next = p2_str_cmp;
    p1_str_cmp_next++;
    p2_str_cmp_next++;
    char_1          = ASCII_ToLower(*p1_str_cmp);
    char_2          = ASCII_ToLower(*p2_str_cmp);
    cmp_len         = 0u;

    while (( char_1          ==  char_2)                &&      /* Cmp strs until non-matching chars (see Note #3c) ... */
           (*p1_str_cmp      != (      CPU_CHAR  )'\0') &&      /* ... or NULL chars                 (see Note #3b) ... */
           ( p1_str_cmp_next != (const CPU_CHAR *)  0 ) &&      /* ... or NULL ptr(s) found          (see Note #3a2);   */
           ( p2_str_cmp_next != (const CPU_CHAR *)  0 ) &&
           ( cmp_len         <  (      CPU_SIZE_T)len_max)) {   /* ... or max nbr chars cmp'd        (see Note #3d2).   */
        p1_str_cmp++;
        p2_str_cmp++;
        p1_str_cmp_next++;
        p2_str_cmp_next++;
        cmp_len++;
        char_1 = ASCII_ToLower(*p1_str_cmp);
        char_2 = ASCII_ToLower(*p2_str_cmp);
    }


    if (cmp_len == len_max) {                                   /* If strs     identical for max len nbr of chars, ...  */
        return (0);                                             /* ... rtn 0                 (see Note #3d2A).          */
    }

    if (char_1 != char_2) {                                     /* If strs NOT identical, ...                           */
         cmp_val = (CPU_INT16S)char_1 - (CPU_INT16S)char_2;     /* ... calc & rtn char diff  (see Note #3c1).           */

    } else if (char_1 == (CPU_CHAR)'\0') {                      /* If NULL char(s) found, ...                           */
         cmp_val = (CPU_INT16S)0;                               /* ... strs identical; rtn 0 (see Note #3b).            */

    } else {
        if (p1_str_cmp_next == (const CPU_CHAR *)0) {
            if (p2_str_cmp_next == (const CPU_CHAR *)0) {       /* If BOTH next str ptrs NULL, ...                      */
                cmp_val = (CPU_INT16S)0;                        /* ... rtn 0                       (see Note #3a2A).    */
            } else {                                            /* If p1_str_cmp_next NULL, ...                         */
                char_2  =  ASCII_ToLower(*p2_str_cmp_next);
                cmp_val = (CPU_INT16S)0 - (CPU_INT16S)char_2;   /* ... rtn neg p2_str_cmp_next val (see Note #3a2B1).   */
            }
        } else {                                                /* If p2_str_cmp_next NULL, ...                         */
            char_1  =  ASCII_ToLower(*p1_str_cmp_next);
            cmp_val = (CPU_INT16S)char_1;                       /* ... rtn pos p1_str_cmp_next val (see Note #3a2B2).   */
        }
    }


    return (cmp_val);
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                             Str_Char()
*
* Description : Search string for first occurrence of specific character.
*
* Argument(s) : pstr            Pointer to string (see Note #1).
*
*               srch_char       Search character.
*
* Return(s)   : Pointer to first occurrence of search character in string, if any    (see Note #2b1).
*
*               Pointer to NULL,                                           otherwise (see Note #2b2).
*
* Caller(s)   : Application.
*
* Note(s)     : (1) String buffer NOT modified.
*
*               (2) (a) IEEE Std 1003.1, 2004 Edition, Section 'strchr() : DESCRIPTION' states that :
*
*                       (1) "The strchr() function shall locate the first occurrence of 'c' ('srch_char') 
*                            ... in the string pointed to by 's' ('pstr')."
*                       (2) "The terminating null byte is considered to be part of the string."
*
*                   (b) IEEE Std 1003.1, 2004 Edition, Section 'strchr() : RETURN VALUE' states that 
*                       "upon completion, strchr() shall return" :
*
*                       (1) "a pointer to the byte," ...
*                       (2) "or a null pointer if the byte was not found."
*                           (A) #### Although NO strchr() specification states to return NULL for 
*                               any other reason(s), NULL is also returned for any error(s).
*
*               (3) String search terminates when :
*
*                   (a) String pointer passed a NULL pointer.
*                       (1) No string search performed; NULL pointer returned.
*
*                   (b) String pointer points to NULL.
*                       (1) String overlaps with NULL address; NULL pointer returned.
*
*                   (c) String's terminating NULL character found.
*                       (1) Search character NOT found in search string; NULL pointer returned 
*                           (see Note #2b2).
*                       (2) Applicable even if search character is the terminating NULL character 
*                           (see Note #2a2).
*
*                   (d) Search character found.
*                       (1) Return pointer to first occurrence of search character in search string
*                           (see Note #2a1).
*********************************************************************************************************
*/

CPU_CHAR  *Str_Char (const  CPU_CHAR  *pstr,
                            CPU_CHAR   srch_char)
{
    CPU_CHAR  *pstr_rtn;


    pstr_rtn