BSD 3 development

[unix-history] / usr / src / cmd / ratfor / rlook.c

#define NULL 0
#define EOS 0
#define HSHSIZ  101
struct  nlist {
       char    *name;
       char    *def;
       int     ydef;
       struct  nlist *next;
};

struct  nlist   *hshtab[HSHSIZ];
struct nlist    *lookup();
char    *install();
char    *malloc();
char    *copy();
int     hshval;

struct nlist *lookup(str)
char *str;
{
       register char *s1, *s2;
       register struct nlist *np;
       static struct nlist nodef;

       s1 = str;
       for (hshval = 0; *s1; )
               hshval += *s1++;
       hshval %= HSHSIZ;
       for (np = hshtab[hshval]; np!=NULL; np = np->next) {
               s1 = str;
               s2 = np->name;
               while (*s1++ == *s2)
                       if (*s2++ == EOS)
                               return(np);
       }
       return(&nodef);
}

char *install(nam, val, tran)
char *nam, *val;
int tran;
{
       register struct nlist *np;

       if ((np = lookup(nam))->name == NULL) {
               np = (struct nlist *)malloc(sizeof(*np));
               np->name = copy(nam);
               np->def = copy(val);
               np->ydef = tran;
               np->next = hshtab[hshval];
               hshtab[hshval] = np;
               return(np->def);
       }
       free(np->def);
       np->def = copy(val);
       return(np->def);
}

char *copy(s)
register char *s;
{
       register char *p, *s1;

       p = s1 = (char *) malloc((unsigned)strlen(s)+1);
       while (*s1++ = *s++);
       return(p);
}