1: /* $Header$ */
   2: 
   3: /*
   4:  * Author: Peter J. Nicklin
   5:  */
   6: #include "null.h"
   7: #include "ptree.h"
   8: /*
   9:  * ptree() searchs for a project directory name in a binary tree. If the
  10:  * search is unsuccessful, a new node is added to the tree.
  11:  */
  12: PTREE *
  13: ptree(p, alias, pd1, pd2)
  14:     PTREE *p;           /* current node pointer */
  15:     char *alias;            /* project directory alias */
  16:     char *pd1;          /* project directory pathname */
  17:     char *pd2;          /* project directory pathname */
  18: {
  19:     char *strsav();         /* save a string somewhere */
  20:     int comp;           /* compare key values */
  21:     int strcmp();           /* string comparison */
  22:     PTREE *palloc();        /* allocate a tree node */
  23: 
  24:     if (p == NULL)
  25:         {           /* a new alias has arrived */
  26:         if ((p = palloc()) == NULL || (p->alias = strsav(alias)) == NULL)
  27:             goto nomemory;
  28:         if (pd1 != NULL)
  29:             {
  30:             if ((p->pd1 = strsav(pd1)) == NULL)
  31:                 goto nomemory;
  32:             p->pd2 = NULL;
  33:             }
  34:         else    {
  35:             if ((p->pd2 = strsav(pd2)) == NULL)
  36:                 goto nomemory;
  37:             p->pd1 = NULL;
  38:             }
  39:         p->left  = p->right = NULL;
  40:         }
  41:     else if ((comp = strcmp(alias, p->alias)) < 0)
  42:         p->left = ptree(p->left, alias, pd1, pd2);
  43:     else if (comp > 0)
  44:         p->right = ptree(p->right, alias, pd1, pd2);
  45:     else if (comp == 0)
  46:         if ((p->pd2 = strsav(pd2)) == NULL)
  47:             {
  48: nomemory:       warn("out of memory");
  49:             exit(2);
  50:             }
  51:     return(p);
  52:     }
  53: 
  54: 
  55: 
  56: /*
  57:  * ptreerm() removes a project directory tree.
  58:  */
  59: void
  60: ptreerm(p)
  61:     PTREE *p;           /* current node pointer */
  62: {
  63:     if (p != NULL)
  64:         {
  65:         if (p->left != NULL)
  66:             ptreerm(p->left);
  67:         if (p->right != NULL)
  68:             ptreerm(p->right);
  69:         free(p->alias);
  70:         if (p->pd1 != NULL)
  71:             free(p->pd1);
  72:         if (p->pd2 != NULL)
  73:             free(p->pd2);
  74:         free((char *) p);
  75:         }
  76: }
  77: 
  78: 
  79: 
  80: /*
  81:  * palloc allocates memory for a project tree node.
  82:  */
  83: static PTREE *
  84: palloc()
  85: {
  86:     char *malloc();         /* memory allocator */
  87: 
  88:     return((PTREE *) malloc(sizeof(PTREE)));
  89:     }

Defined functions

palloc defined in line 83; used 2 times
ptree defined in line 12; used 9 times
ptreerm defined in line 59; used 5 times
Last modified: 1985-07-03
Generated: 2016-12-26
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