root/op/1.30/atov.c

/* +-------------------------------------------------------------------+ */
/* | Copyright 1988,1991, David Koblas.                                | */
/* |   Permission to use, copy, modify, and distribute this software   | */
/* |   and its documentation for any purpose and without fee is hereby | */
/* |   granted, provided that the above copyright notice appear in all | */
/* |   copies and that both that copyright notice and this permission  | */
/* |   notice appear in supporting documentation.  This software is    | */
/* |   provided "as is" without express or implied warranty.           | */
/* +-------------------------------------------------------------------+ */

#include <string.h>
#include        <ctype.h>

#ifdef TEST
main(argc,argv)
int     argc;
char    **argv;
{
        int     i;
        for (i=1;i<argc;i++)
                printf("%10s  == %d\n",argv[i],atov(argv[i],0));
}
#endif

int atov(str,type)
char    *str;
int     type;
{
        int             sign = 1;
        int             i;
        char            c;
        int             val=0,n;

        i=0;
        while ((str[i]==' ') || (str[i]=='\t')) i++;
        if (str[i]=='-')  {
                sign = -1;
                i++;
        } else if (str[i]=='+') {
                sign = 1;
                i++;
        }
        if (type==0)  {
                if (str[i]=='0') {
                        i++;
                        if (str[i]=='%') {
                                i++;
                                type=2;
                        } else if (str[i]=='x') {
                                i++;
                                type=16;
                        } else {
                                type=8;
                        }
                } else {
                        type=10;
                }
        }
        for (;i<strlen(str);i++) {
                c=str[i];
                if (isdigit(c)) {
                        n = c - '0';
                } else if (isupper(c)) {
                        n = c - 'A' + 10;
                } else if (islower(c)) {
                        n = c - 'a' + 10;
                } else {
                        goto    out;
                }
                if (n>=type)
                        goto out;
                val = (val*type)+n;
        }
out:    
        return(val * sign);
}