BSD 4_4_Lite1 development

[unix-history] / usr / src / contrib / rc-1.4 / list.c

/* list.c: routines for manipulating the List type */

#include "rc.h"

/*
  These list routines assign meta values of null to the resulting lists;
  it is impossible to glob with the value of a variable unless this value
  is rescanned with eval---therefore it is safe to throw away the meta-ness
  of the list.
*/

/* free a list from malloc space */

extern void listfree(List *p) {
       while (p != NULL) {
               List *n = p->n;
               efree(p->w);
               efree(p);
               p = n;
       }
}

/* Copy list into malloc space (for storing a variable) */

extern List *listcpy(List *s, void *(*alloc)(size_t)) {
       List *top, *r;
       for (top = r = NULL; s != NULL; s = s->n) {
               if (top == NULL)
                       r = top = (*alloc)(sizeof (List));
               else
                       r = r->n = (*alloc)(sizeof (List));
               r->w = (*alloc)(strlen(s->w) + 1);
               strcpy(r->w, s->w);
               r->m = NULL;
       }
       if (r != NULL)
               r->n = NULL;
       return top;
}

/* Length of list */

extern size_t listlen(List *s) {
       size_t size;
       for (size = 0; s != NULL; s = s->n)
               size += strlen(s->w) + 1;
       return size;
}

/* Number of elements in list */

extern int listnel(List *s) {
       int nel;
       for (nel = 0; s != NULL; s = s->n)
               nel++;
       return nel;
}