/******************************************************************************
* detab.c
*	Convert all tabs to n-column spaces.
*
* Notice
*	Copyright (c)Jul 1987, David R Tribble.
*
* 1.00 04-16-1985 drt.
* 1.01 07-26-1986 drt.	Cleaned program up a bit.
* 1.02 04-03-1987 drt.	Fixed usage.
* 1.03 06-16-1987 drt.	Added setvbuf() usage.
*
* 2.00 07-20-1987 drt.	New main(), uses fsearch functions.
* 2.01 12-17-1987 drt.	Uses fpsearch functions.
*/


/* Identification */

#define ID_TITLE	"DETAB"
#define ID_DATE		"12-17-1987"
#define ID_VERS		"2.01"
#define ID_FILE		__FILE__
#define ID_AUTH		"David R. Tribble"
#define ID_COMP		__DATE__ " " __TIME__

static const char	copyright[] =
	"Copyright (c)1987, " ID_AUTH ".";

static const char	id[] =
	"@(#) " ID_DATE " " ID_VERS " " ID_FILE;

static const char	id_compile[] =
	"[" ID_TITLE " " ID_VERS ", " ID_DATE "] <" ID_COMP ">";

static const char	title[] =	ID_TITLE;
static const char	date[] =	ID_DATE;
static const char	vers[] =	ID_VERS;
static const char	auth[] =	ID_AUTH;
static const char	file[] =	ID_FILE;

static const char *	prog = title;


/* System includes */

#define NO_EXT_KEYS
#define LINT_ARGS

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>


/* Local includes */

#include "optargs.h"

#ifndef NFSEARCH
 #include "fsearch.h"
#endif


/* Manifest constants */

#define TABSZ		8	/* default tab spacing			*/

#define HT	'\t'
#define NL	'\n'
#define FF	'\f'
#define SP	' '


/******************************************************************************
* detab
*	Convert tabs to equivalent whitespace run of spaces, reading
*	from file in and writing to file out.
*/

void detab(FILE *in, FILE *out, int tabsz)
{
    int		c;
    int		col;

    col = 0;
    c = getc(in);
    while (c != EOF) {
        while (c != NL  &&  c != EOF) {
            if (c == HT) {
                for (;  col < tabsz;  ++col)
                    putc(SP, out);
                col = 0;
            }
            else {
                putc(c, out);
                ++ col;
                if (col >= tabsz)
                    col = 0;
            }
            c = getc(in);
        }
        if (c != EOF) {
            putc(c, out);
            c = getc(in);
        }
        col = 0;
    }
}


/******************************************************************************
* main
*/

static char	invbuf[20*1024];
static char	outvbuf[20*1024];

int main(int argc, char **argv)
{
    int		tablen;
    FILE *	in;
    int		i;

    /* get -N option */
    tablen = TABSZ;		/* default	*/
    OPTIONS
        default:
            tablen = atoi(OPTSTR-1);
            NEXTARG;
    ENDOPTIONS

    setvbuf(stdout, outvbuf, _IOFBF, sizeof outvbuf);

    /* get filename, if any */
    if (argc > 0) {
        for (i = 0;  i < argc;  ++i)
        {
#ifdef NFSEARCH
            in = fopen(argv[i], "r");
            if (in != NULL)
            {
                setvbuf(in, invbuf, _IOFBF, sizeof invbuf);
                fprintf(stderr, "%s\n", argv[i]);
                detab(in, stdout, tablen);
                fclose(in);
            }
            else
                fprintf(stderr, "%s: cannot read %s\n",
                    prog, argv[i]);
#else
            if (fpstart(argv[i], NULL, _A_NORMAL))
            {
                while (fpnext(NULL, NULL, 1))
                {
                    in = fopen(fps_name, "r");
                    if (in != NULL)
                    {
                        setvbuf(in, invbuf, _IOFBF, sizeof invbuf);
                        fprintf(stderr, "%s\n", fps_name);
                        detab(in, stdout, tablen);
                        fclose(in);
                    }
                    else
                        fprintf(stderr, "%s: cannot read %s\n",
                            prog, fps_name);
                }
            }
            else
                fprintf(stderr, "%s: cannot find %s\n",
                    prog, argv[i]);
#endif
        }
    }
    else
    if (! isatty(fileno(stdin)))
    {
        setvbuf(stdin, invbuf, _IOFBF, sizeof invbuf);
        detab(stdin, stdout, tablen);
    }
    else
        goto usage;

    return EXIT_SUCCESS;

usage:
    fprintf(stderr, "[%s, %s %s]\n"
        "Convert tabs into spaces.\n\n",
        prog, vers, date);
    fprintf(stderr,
        "usage: %s [-N] file...\n"
        "or:    %s [-N] <input\n\n",
        prog, prog);
    fprintf(stderr,
        "Where N is the number of spaces in a tab.\n"
        "Filenames may contain wildcards (? or *).\n");

    return EXIT_FAILURE;
}


/* end detab.c */