atoi.c

来自「基于mcx314的运动控制」· C语言 代码 · 共 37 行

#include "Uart.h"

int atoi(char *pstr)
{   int n,NBase,sig;
	char *pstr_back;
	
	pstr_back = pstr;

    if(*pstr == '\0' ) return(-1);
    while(*pstr == ' '  || *pstr == '=' || *pstr == '.' ) pstr++;
    NBase = 10;
    sig   = 1;
    if( *pstr == '-' ) { pstr++; sig = -1; }
    if( *pstr == '0' ) pstr++;
    if( *pstr == 'x' ||  *pstr == 'X' )
    {   pstr++;
        NBase = 16;
    }
    
    n = 0;
    while(1)
    {   if     ( *pstr >= '0' && *pstr <= '9' )
                  n = n*NBase + (*pstr - '0');
        else if( *pstr >= 'a' && *pstr <= 'f' )
                  n = n*NBase + (*pstr - 'a')+10;
        else if( *pstr >= 'A' && *pstr <= 'F' )
                  n = n*NBase + (*pstr - 'A')+10;
        else
                  break;
        pstr++;
    }
    
    pstr = pstr_back;
    return(n*sig);
}