sources-request@panda.UUCP (12/10/85)
Mod.sources: Volume 3, Issue 60
Submitted by: genrad!decvax!ihnp4!homebru!ignatz
Several weeks ago, James Gillogly submitted this routine, directory(),
for manipulating MS/PC-DOS directories. While it was quite useful,
I've found that there were some things that I really needed; the
result is the modified directory routine below. It's been in use for
some time now, so I think all the bugs are out. Specifically, the
changes I added are:
- Provided a calling convention for the release of the
acquired memory. (If processing multiple wildcard entries
on the same command line, the old version ate memory)
- Converted to run under both Aztec and Lattice 'C'
- Modified returned namelist so that it's a null-terminated
list of pointers, a la 'argv'
- Provided an externally defined flag that allows the savvy
user to specify inclusion or exclusion of different file
types; most useful for finding subdirectories.
- Modified so that it returns the full path, and the drive
specifier if provided, rather than just the filename. This
makes the returned filename strings directly usable by
routines such as 'open', 'creat', etc.
I hope you find these useful; I have.
Dave Ihnat
Analysts International Corporation
ihnp4!aicchi!ignatz || ihnp4!homebru!ignatz
====================== Hier Schneiden =============================
/* direct.c - Search a directory for files matching the description, and
* return a sorted list of the matching files. Supports drive name,
* path, and wildcards. Expand your argv and amaze your friends.
*
* For use with Lattice C; last compiled with version 2.15.
* Requires STDIO.H and DOS.H .
*
* IF LATTICE:
* Allocates space for the filenames with getmem, so be careful with
* your rlsmem's.
*
* ELSE uses malloc(),free()
*
* (c) 1984 James J. Gillogly. All rights reserved.
* Copyright abandoned 28 Sep 1985.
*
* Modified 10/6/85 by D. M. Ihnat
*
* Usage: n = directory(filename, names);
* integer n; Returns number of files found.
* char *filename; May include drive name, path, *, and ?
* char ***names; Address of the char ** you want pointing to the list.
*
* sel_disk(letter); char letter;
* Sets current drive to this one (A, B, etc); returns NO on error.
* n = directory(filename, names); char *filename, **names;
* Search current directory for this filename (may include ?'s), and
* allocate enough space for all the resulting filenames.
* Returns number of files found.
* first_file(filename, buffer)
* Looks for the first file set up in the global file control block;
* returns NO if none.
* next_file(buffer)
* Looks for the next file; must be preceded by a first_file().
* set_dta(adr); char *adr;
* Sets the disk transfer address used by the directory functions.
*
* 29 Aug 84: sel_disk(letter), directory(), first_file(), next_file(),
* set_dta(adr)
*
* 17 Sep 85: changed the calling sequence for directory:
* n = directory(filename, names); char *filename, ***names;
* It now takes the address of a char ** pointer pointer.
* Support drive letters and paths (requires DOS 2.0 or higher).
*
* 6 Oct 85: Modified by Dave Ihnat
* - Supports both Lattice and non-Lattice compilers (notably Aztec)
* - Now returns a pointer to a NULL-terminated namelist , similar to **argv
* - Supports a call of the form directory((char *)NULL,names) to
* properly release used memory. Returns 0 if release OK, else -1.
* - Added extern unsigned _dir_mode_ to select type of search. Changes
* to this flag are only valid when starting a search; it is a
* logical OR of:
* 0x0 : Normal files (default)
* 0x1 : Read-only files
* 0x2 : Hidden files
* 0x4 : System files
* 0x8 : Volume ID (not recommended)
* 0x10 : Directories
*
* 24 Oct 85: Modified by Dave Ihnat
* - Modified to check for existence of a drive designation or a path
* prefix; if one exists, remember it and prepend it to every filename
* returned. This makes the returned file list directly usable by
* in calls such as open(), close().
*/
#include <stdio.h>
#include <ctype.h>
#ifdef LATTICE
#include <dos.h>
#define MEMALLOC getmem
#define MEMFREE(a,b) rlsmem(a,b)
#else
#include <ctype.h>
#define MEMALLOC malloc
#define MEMFREE(a,b) free(a)
#endif
/*
* Both Aztec 3.20d and Lattice 2.15 have strchr/strrchr; this is for any
* others who may NOT.
*/
#define RTCHAR strrchr
#define SEL_DISK 0x0E /* BDOS: select current disk drive */
#define SET_DTA 0x1A /* BDOS: set disk transfer address */
#define FIND_FRST 0x4E /* BDOS: find first file, long form */
#define FIND_NEXT 0x4F /* BDOS: find next file, long form */
#define ERROR 0xFF /* BDOS: error return */
#define NOTFOUND 2 /* Error return: file not found */
#define NOMORE 18 /* Error return: no more files */
#define YES 1
#define NO 0
#define MAXNAMES 100 /* temp - will get cleverer later */
struct dirstruct /* temporary holding area for entries */
{ struct dirstruct *next; /* pointer to next entry */
char *fname; /* filename of this entry */
};
struct EFCB /* FCB for path-type calls */
{ char reserved[21];
char attrib_found;
char file_time[2];
char file_date[2];
char low_size[2];
char high_size[2];
char file_name[13];
};
unsigned _dir_mode_ = 0; /* Initialize to use only normal files */
directory(filename, names) /* look up filename in the directory */
char *filename, ***names;
{ char buffer[80];
struct EFCB dta;
register struct dirstruct *p,*q;/* trundle down the directory list */
struct dirstruct *dir_root; /* root of directory list */
register int n; /* number of entries */
register int i, j;
char *ptr_prefix; /* For storage of any prefix data */
int len_prefix;
char *MEMALLOC();
char *RTCHAR();
/* If filename is a null path, then user is trying to release memory */
if (filename == (char *)NULL)
return(free_direct(names));
/*
* If there is a drive designator or a path in the filename,
* save it. Check first for a path; if there is one, then
* the drive designator, if any, will be saved as a side effect.
* Otherwise, explicitly save the descriptor. Notice that, as either
* the MS-DOS directory delimiter '\', or the Unix-style '/' may
* be given to MS-DOS from within a program, BOTH must be tested!
*/
len_prefix = 0;
if(((ptr_prefix = RTCHAR(filename,'\\')) != (char *)NULL) ||
((ptr_prefix = RTCHAR(filename,'/')) != (char *)NULL) )
{
/* Path; get storage, and copy it */
char *srcptr,*dstptr,*endptr; /* Local block storage */
len_prefix = (ptr_prefix - filename) +2; /* Allow for null */
endptr = ptr_prefix+1; /* Point just after the delimiter */
ptr_prefix = MEMALLOC(len_prefix);
for(srcptr=filename,dstptr=ptr_prefix;srcptr < endptr;dstptr++,srcptr++)
*dstptr = _toupper(*srcptr);
*dstptr = '\0'; /* Null terminate */
}else if(filename[1] == ':')
{
/* Only a drive designator; save it. */
ptr_prefix = MEMALLOC(3); /* 2 characters + null */
ptr_prefix[0] = _toupper(filename[0]);
ptr_prefix[1] = filename[1];
ptr_prefix[2] = '\0';
len_prefix = 2;
}
if (!first_file(filename, buffer, &dta))
return 0; /* no files found */
n = 1; /* one entry found so far */
p->next = 0;
dir_root = (struct dirstruct *) MEMALLOC(sizeof (struct dirstruct));
p = dir_root; /* point at top of directory list */
p->fname = (char *) MEMALLOC(strlen(buffer) + 1);
strcpy(p->fname, buffer); /* save the first filename */
while (next_file(buffer, &dta))
{ n++; /* looks like another winner */
p->next = (struct dirstruct *) MEMALLOC(sizeof (struct dirstruct));
p = p->next; /* point at the next entry */
p->fname = (char *) MEMALLOC(strlen(buffer) + 1);
strcpy(p->fname, buffer); /* save it */
}
p->next = 0; /* end of the line */
/* (n names) + NULL ptr */
*names = (char **) MEMALLOC((n+1) * sizeof (char *));
for (i = 0, p = dir_root; i < n; i++) /* insertion sort on pointers */
{ for (j = i; j > 0; j--) /* where does this one go? */
{ if (strcmp((*names)[j - 1], p->fname) < 0) break;
(*names)[j] = (*names)[j - 1];
}
(*names)[j] = (char *)MEMALLOC(strlen(p->fname)+len_prefix+1);
if(len_prefix)
{
strcpy((*names)[j],ptr_prefix);
strcat((*names)[j], p->fname);
}else
strcpy((*names)[j], p->fname);
#ifdef VERBOSE
printf("%s goes into slot %d.\n", p->fname, j);
#endif VERBOSE
q = p; /* save it so we can delete it */
p = p->next; /* after pressing on to the next entry */
MEMFREE(q, sizeof (struct dirstruct));
}
(*names)[n] = (char *)NULL; /* Provide a null terminator */
if(len_prefix)
MEMFREE(ptr_prefix,strlen(ptr_prefix)); /* Return the path memory */
#ifdef VERBOSE
printf("Here they are:\n");
for (i = 0; i < n; i++)
printf("\t%s\n", (*names)[i]);
printf("Should be null terminator: 0x%x\n",(unsigned)names[n]);
#endif VERBOSE
return n;
}
first_file(filename, buffer, dta) /* set up FCB and get first file */
char *filename, *buffer;
struct EFCB *dta;
{ register char *s, *t;
register int i, ret;
for (s = filename; *s; s++) if (islower(*s)) *s = toupper(*s);
#ifdef LARGEDATA
ret = bdosx(SET_DTA, dta, 0); /* set up data transfer area */
ret = bdosx(FIND_FRST, filename, _dir_mode_);
#else
ret = bdos(SET_DTA, dta, 0); /* set up data transfer area */
ret = bdos(FIND_FRST, filename, _dir_mode_);
#endif
if (ret == NOTFOUND || ret == NOMORE) return NO;
getname(buffer, dta); /* transfer the filename found to the caller */
return YES;
}
next_file(buffer, dta) /* look up next file with the same attributes */
char *buffer;
struct EFCB *dta;
{ int ret;
if (bdos(FIND_NEXT, 0, 0) == NOMORE) return NO;
getname(buffer, dta);
return YES;
}
getname(buffer, dta) /* transfer filename from dta to the buffer area */
char *buffer;
struct EFCB *dta;
{ strcpy(buffer, dta->file_name);
}
sel_disk(letter) /* make this disk the current one */
char letter;
{ int ret;
ret = bdos(SEL_DISK, letter - 'A', 0);
return ret;
}
free_direct(names)
char ***names;
{
int index;
/*
* Release each of the filename strings. There's room for
* some twiddling here to avoid unnecessary strlen calls,
* but this should be so rarely called that the overhead should
* be acceptable. Feel free to change it, however, if you wish...
*/
for(index = 0;(*names)[index] != (char *)NULL;index++)
if(MEMFREE((*names)[index],(strlen((*names)[index])+1)))
return(-1); /* Corrupted--don't trust anything */
/* Now release the pointer structure */
if(MEMFREE(*names,(index * sizeof(char *))))
return(-1);
/* Finally, remove any temptation to touch that released memory */
*names = (char **)NULL;
return(0);
}