source: trunk/libs/mini-libc/string.c @ 441

/*
 * string.c - Character string handling API implementation.
 * 
 * Author     Alain Greiner (2016,2017)
 *
 * Copyright (c) UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#define  NULL  (void *)0

///////////////////////////
inline int tolower( int c )
{
   if (c >= 'A' && c <= 'Z') return (c | 0x20);
   else                      return c;
}


///////////////////////////
inline int toupper( int c )
{
   if (c >= 'a' && c <= 'z') return (c & ~(0x20));
   else                      return c;
}

///////////////////////////////////////
unsigned int strlen( const char * str )
{
        register const char * ptr = str;

        while (* ptr) ptr++;

        return (ptr - str);
}

///////////////////////////////////////
unsigned int strnlen( const char * str,
                      unsigned int     maxlen )
{
        register const char *ptr = str;

        while (*ptr && (maxlen-- > 0)) ptr++;

        return (ptr - str);
}

////////////////////////////
int strcmp( const char * s1,
            const char * s2 )
{

        while (*s1 && *s1 == *s2)
        {
                s1 ++;
                s2 ++;
        }

        return (*s1 - *s2);
}

//////////////////////////////
int strncmp( const char   * s1,
             const char   * s2,
             unsigned int   n )
{ 
        if (n == 0)
                return s1 - s2;    // pseudo random result...

        while (*s1 && (*s1 == *s2) && (n > 1))
        {
                s1 ++;
                s2 ++;
                n--;
        }

        return (*s1 - *s2);
}

//////////////////////////////////
int strcasecmp( const char * str1,
                const char * str2 )
{
        char c1;
        char c2;

        do
    {
                c1 = (char)toupper( (int)*++str1 );
                c2 = (char)toupper( (int)*++str2 );
                c2 = toupper(*++str2);
        }
    while(c1 && c1 == c2);

        return (c1 - c2);
}

///////////////////////////
char * strcpy (char * dest,
               char * src )
{
        char *src_ptr = src;
        char *dst_ptr = dest;

        while(*src_ptr) *(dst_ptr++) = *(src_ptr++);

        *dst_ptr = 0;
        return dest;
}

////////////////////////////////////
char * strncpy( char         * dest,
                char         * src,
                unsigned int   n )
{
        unsigned int i;

        for (i = 0; (i < n) && (src[i] != '\0') ; i++) dest[i] = src[i];

        for (; i < n; i++) dest[i] = '\0';

        return dest;
}

//////////////////////////////
char * strstr( char       * s,
               const char * find )
{
    char     sc;
    char     c;
    unsigned int len;

    if ((c = *find++) != 0) 
    {
        len = strlen( find );
        do 
        {
            do 
            {
                if ((sc = *s++) == 0) return NULL;
            } 
            while (sc != c);
        } 
        while (strncmp(s, find, len) != 0);
        s--;
    }
    return s;
}

//////////////////////////////
char * strchr( const char * s,
               int          c )
{
        while(*s && *s != (char) c) s++;

        if(*s == (char) c) return (char*)s;

        return NULL;
}

///////////////////////////////
char * strrchr( const char * t,
                int          c )
{
        register char         ch;
        register const char * l = 0;

        ch = c;
        for (;;) 
    {
                if (*t == ch) l=t;
                if (!*t) return (char*)l;
                ++t;
        }
        return (char*)l;
}