/* Copyright (C) 1992, 1993, 1996, 1998 Aladdin Enterprises.  All rights reserved.

   This file is part of Aladdin Ghostscript.

   Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
   or distributor accepts any responsibility for the consequences of using it,
   or for whether it serves any particular purpose or works at all, unless he
   or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
   License (the "License") for full details.

   Every copy of Aladdin Ghostscript must include a copy of the License,
   normally in a plain ASCII text file named PUBLIC.  The License grants you
   the right to copy, modify and redistribute Aladdin Ghostscript, but only
   under certain conditions described in the License.  Among other things, the
   License requires that the copyright notice and this notice be preserved on
   all copies.
 */

/*$Id: gp_dosfs.c $ */
/* Common routines for MS-DOS (any compiler) and DesqView/X, */
/* which has a MS-DOS-like file system. */
#include "dos_.h"
#include "gx.h"
#include "gp.h"

/* ------ Printer accessing ------ */

/* Put a printer file (which might be stdout) into binary or text mode. */
/* This is not a standard gp procedure, */
/* but all MS-DOS configurations need it. */
void
gp_set_file_binary(int prnfno, bool binary)
{
    union REGS regs;

    regs.h.ah = 0x44;		/* ioctl */
    regs.h.al = 0;		/* get device info */
    regs.rshort.bx = prnfno;
    intdos(&regs, &regs);
    if (regs.rshort.cflag != 0 || !(regs.h.dl & 0x80))
	return;			/* error, or not a device */
    if (binary)
	regs.h.dl |= 0x20;	/* binary (no ^Z intervention) */
    else
	regs.h.dl &= ~0x20;	/* text */
    regs.h.dh = 0;
    regs.h.ah = 0x44;		/* ioctl */
    regs.h.al = 1;		/* set device info */
    intdos(&regs, &regs);
}

/* ------ File accessing ------ */

/* Set a file into binary or text mode. */
int
gp_setmode_binary(FILE * pfile, bool binary)
{
    gp_set_file_binary(fileno(pfile), binary);
    return 0;			/* Fake out dos return status */
}

/* ------ File names ------ */

/* Define the character used for separating file names in a list. */
const char gp_file_name_list_separator = ';';

/* Define the string to be concatenated with the file mode */
/* for opening files without end-of-line conversion. */
const char gp_fmode_binary_suffix[] = "b";

/* Define the file modes for binary reading or writing. */
const char gp_fmode_rb[] = "rb";
const char gp_fmode_wb[] = "wb";

/* Answer whether a file name contains a directory/device specification, */
/* i.e. is absolute (not directory- or device-relative). */
bool
gp_file_name_is_absolute(const char *fname, unsigned len)
{				/* A file name is absolute if it contains a drive specification */
    /* (second character is a :) or if it start with 0 or more .s */
    /* followed by a / or \. */
    if (len >= 2 && fname[1] == ':')
	return true;
    while (len && *fname == '.')
	++fname, --len;
    return (len && (*fname == '/' || *fname == '\\'));
}

/* Answer the string to be used for combining a directory/device prefix */
/* with a base file name.  The file name is known to not be absolute. */
const char *
gp_file_name_concat_string(const char *prefix, unsigned plen,
			   const char *fname, unsigned len)
{
    if (plen > 0)
	switch (prefix[plen - 1]) {
	    case ':':
	    case '/':
	    case '\\':
		return "";
	};
    return "\\";
}
