jrb@wdl1.UUCP (John R Blaker) (02/17/84)
/*==========================================================================*
* == D I R E C T == *
*==========================================================================*
* John R Blaker -- Ford Aerospace & Communications Corporation -- Oct 1982 *
*==========================================================================*
* This file contains routines which put the disc directory into a more *
* readily usable form. It also contains routines for accessing that new *
* form. This file contains the following functions: *
* makedir() Gets the directory off the disc and into memory *
* findentry() Ginds an entry matching its argument and returns a *
* pointer to it. *
* The new form is a linked list of structures the diefinition of wich is in*
* 'rt11.h'. *
*==========================================================================*
*/
/*
* Include files
*/
#include "rt11.h" /* Global definitions */
/*
* makedir()
* this function builds the in-memory directory referenced elsewhere
* in the program. It uses rt11_to_a() tor translate the filename from
* RADIX-50 to ASCII. The in-memory directory is implemented as a singly
* linked list. The routine uses calloc() to allocate space for new
* nodes.
* The routine assumes that there is only one segment in the directory.
*/
makedir()
{
DIR_SEGMNT seg1; /* A segment of the disc directory */
DIR_SEGMENT *seg_ptr = &seg1; /* Pointer to that segment */
char filename[15]; /* String to hold filename */
int index; /* Loop index */
int i; /* Loop index */
int j; /* Loop index */
MEM_DIR *newnode; /* Pointer to newly allocated node */
unsigned cur_addr; /* Current address */
MEM_DIR *cur_node; /* Current node */
char *calloc(); /* Memory allocator */
char fname[15]; /* Name with embedded spaces removed */
trace("Making in-memory directory");
dir_header = NULL;
getsegment(6, (char *)seg_ptr);
cur_addr = (seg_ptr -> ds_header).dh_addr;
for (index = 0; index < 72; index++) {
if (((((seg_ptr -> ds_direct)[index]).de_status) & ST_EOSG) != 0)
break;
if (((((seg_ptr -> ds_direct)[index]).de_status) & ST_EMPT) != 0)
continue;
rt11_to_a(((seg_ptr -> ds_direct)[index]).de_fln1,
((seg_ptr -> ds_direct)[index]).de_fln2,
((seg_ptr -> ds_direct)[index]).de_type,
filename);
for (i = 0, j = 0; j < 15;) { /* Get rid of embedded spaces */
if (filename[j] == ' ')
j++;
else
fname[i++] = filename[j++];
} /* for */
strcpy(filename, fname);
trace(filename);
newnode = (MEM_DIR *)calloc(1, sizeof(MEM_DIR));
strcpy(newnode -> md_name, filename);
newnode -> md_addr = cur_addr;
cur_addr += (((seg_ptr -> ds_direct)[index]).de_length);
newnode -> md_size = ((seg_ptr -> ds_direct)[index]).de_length * BLOCKSIZE;
newnode -> md_date = ((seg_ptr -> ds_direct)[index]).de_date;
newnode -> md_next = NULL;
if (dir_header == NULL) {
dir_header = newnode;
} else {
cur_node = dir_header;
while (cur_node -> md_next != NULL)
cur_node = cur_node -> md_next;
cur_node -> md_next = newnode;
} /* if...else */
} /* for */
} /* makedir */
/*
* findentry()
* This does a linear search of the in-memory directory
* for the given filename. If found, a pointer to it is
* returned. If it isn't foundan error message is printed
* and NULL is returned.
*/
MEM_DIR *findentry(name)
char name[]; /* Filename to be found */
{
MEM_DIR *current_entry; /* Current location in directory */
trace("Got to findentry()");
current_entry = dir_header;
while (current_entry != NULL) {
if (strcmp(current_entry -> md_name, name) == 0)
return(current_entry);
else
current_entry = current_entry -> md_next;
} /* while */
error("File not found");
return(NULL);
} /* findentry */