/*      $NetBSD: paste.c,v 1.16 2011/09/06 18:24:43 joerg Exp $ */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam S. Moskowitz of Menlo Consulting.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
/*static char sccsid[] = "from: @(#)paste.c     8.1 (Berkeley) 6/6/93";*/
__RCSID("$NetBSD: paste.c,v 1.16 2011/09/06 18:24:43 joerg Exp $");
#endif /* not lint */

#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

static void     parallel(int, char **);
static void     sequential(char **);
static int      tr(char *);
__dead static void      usage(void);

static char dflt_delim[] = "\t";
static char *delim = dflt_delim;
static int delimcnt = 1;

int
main(int argc, char **argv)
{
        int ch, seq;

        seq = 0;
        while ((ch = getopt(argc, argv, "d:s")) != -1) {
                switch (ch) {
                case 'd':
                        delim = strdup(optarg);
                        delimcnt = tr(delim);
                        break;
                case 's':
                        seq = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (seq)
                sequential(argv);
        else
                parallel(argc, argv);
        exit(0);
}

static void
parallel(int argc, char **argv)
{
        char ch, *dp, *line;
        FILE **fpp, *fp;
        size_t line_len;
        int cnt, output;

        fpp = calloc(argc, sizeof *fpp);
        if (fpp == NULL)
                err(1, "calloc");

        for (cnt = 0; cnt < argc; cnt++) {
                if (strcmp(argv[cnt], "-") == 0)
                        fpp[cnt] = stdin;
                else if (!(fpp[cnt] = fopen(argv[cnt], "r")))
                        err(1, "%s", argv[cnt]);
        }

        for (;;) {
                /* Start with the NUL at the end of 'delim' ... */
                dp = delim + delimcnt;
                output = 0;
                for (cnt = 0; cnt < argc; cnt++) {
                        fp = fpp[cnt];
                        if (fp == NULL)
                                continue;
                        line = fgetln(fp, &line_len);
                        if (line == NULL) {
                                /* Assume EOF */
                                if (fp != stdin)
                                        fclose(fp);
                                fpp[cnt] = NULL;
                                continue;
                        }
                        /* Output enough separators to catch up */
                        do {
                                ch = *dp++;
                                if (ch)
                                        putchar(ch);
                                if (dp >= delim + delimcnt)
                                        dp = delim;
                        } while (++output <= cnt);
                        /* Remove any trailing newline - check for last line */
                        if (line[line_len - 1] == '\n')
                                line_len--;
                        printf("%.*s", (int)line_len, line);
                }

                if (!output)
                        break;

                /* Add separators to end of line */
                while (++output <= cnt) {
                        ch = *dp++;
                        if (ch)
                                putchar(ch);
                        if (dp >= delim + delimcnt)
                                dp = delim;
                }
                putchar('\n');
        }

        free(fpp);
}

static void
sequential(char **argv)
{
        FILE *fp;
        int cnt;
        char ch, *p, *dp;
        char buf[_POSIX2_LINE_MAX + 1];

        for (; (p = *argv) != NULL; ++argv) {
                if (p[0] == '-' && !p[1])
                        fp = stdin;
                else if (!(fp = fopen(p, "r"))) {
                        warn("%s", p);
                        continue;
                }
                if (fgets(buf, sizeof(buf), fp)) {
                        for (cnt = 0, dp = delim;;) {
                                if (!(p = strchr(buf, '\n')))
                                        err(1, "%s: input line too long.",
                                            *argv);
                                *p = '\0';
                                (void)printf("%s", buf);
                                if (!fgets(buf, sizeof(buf), fp))
                                        break;
                                if ((ch = *dp++) != 0)
                                        putchar(ch);
                                if (++cnt == delimcnt) {
                                        dp = delim;
                                        cnt = 0;
                                }
                        }
                        putchar('\n');
                }
                if (fp != stdin)
                        (void)fclose(fp);
        }
}

static int
tr(char *arg)
{
        int cnt;
        char ch, *p;

        for (p = arg, cnt = 0; (ch = *p++); ++arg, ++cnt)
                if (ch == '\\')
                        switch(ch = *p++) {
                        case 'n':
                                *arg = '\n';
                                break;
                        case 't':
                                *arg = '\t';
                                break;
                        case '0':
                                *arg = '\0';
                                break;
                        default:
                                *arg = ch;
                                break;
                } else
                        *arg = ch;

        if (!cnt)
                errx(1, "no delimiters specified.");
        *arg = '\0';
        return(cnt);
}

static void
usage(void)
{
        (void)fprintf(stderr, "paste: [-s] [-d delimiters] file ...\n");
        exit(1);
}