/*      $NetBSD: util.c,v 1.9 2011/02/27 17:33:37 joerg Exp $   */
/*      $OpenBSD: util.c,v 1.39 2010/07/02 22:18:03 tedu Exp $  */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999 James Howard and Dag-Erling Smørgrav
 * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
 * Copyright (C) 2017 Kyle Evans <kevans@FreeBSD.org>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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>
#include <sys/stat.h>
#include <sys/types.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fnmatch.h>
#include <fts.h>
#include <libgen.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>

#include "grep.h"

static bool      first_match = true;

/*
 * Match printing context
 */
struct mprintc {
        long long       tail;           /* Number of trailing lines to record */
        int             last_outed;     /* Number of lines since last output */
        bool            doctx;          /* Printing context? */
        bool            printmatch;     /* Printing matches? */
        bool            same_file;      /* Same file as previously printed? */
};

static void procmatch_match(struct mprintc *mc, struct parsec *pc);
static void procmatch_nomatch(struct mprintc *mc, struct parsec *pc);
static bool procmatches(struct mprintc *mc, struct parsec *pc, bool matched);
#ifdef WITH_INTERNAL_NOSPEC
static int litexec(const struct pat *pat, const char *string,
    size_t nmatch, regmatch_t pmatch[]);
#endif
static bool procline(struct parsec *pc);
static bool printline(struct parsec *pc, int sep, size_t *last_out);
static void printline_metadata(struct str *line, int sep);

bool
file_matching(const char *fname)
{
        char *fname_base, *fname_buf;
        bool ret;

        ret = finclude ? false : true;
        fname_buf = strdup(fname);
        if (fname_buf == NULL)
                err(2, "strdup");
        fname_base = basename(fname_buf);

        for (unsigned int i = 0; i < fpatterns; ++i) {
                if (fnmatch(fpattern[i].pat, fname, 0) == 0 ||
                    fnmatch(fpattern[i].pat, fname_base, 0) == 0)
                        /*
                         * The last pattern matched wins exclusion/inclusion
                         * rights, so we can't reasonably bail out early here.
                         */
                        ret = (fpattern[i].mode != EXCL_PAT);
        }
        free(fname_buf);
        return (ret);
}

static inline bool
dir_matching(const char *dname)
{
        bool ret;

        ret = dinclude ? false : true;

        for (unsigned int i = 0; i < dpatterns; ++i) {
                if (dname != NULL && fnmatch(dpattern[i].pat, dname, 0) == 0)
                        /*
                         * The last pattern matched wins exclusion/inclusion
                         * rights, so we can't reasonably bail out early here.
                         */
                        ret = (dpattern[i].mode != EXCL_PAT);
        }
        return (ret);
}

/*
 * Processes a directory when a recursive search is performed with
 * the -R option.  Each appropriate file is passed to procfile().
 */
bool
grep_tree(char **argv)
{
        FTS *fts;
        FTSENT *p;
        int fts_flags;
        bool matched, ok;
        const char *wd[] = { ".", NULL };

        matched = false;

        /* This switch effectively initializes 'fts_flags' */
        switch(linkbehave) {
        case LINK_EXPLICIT:
                fts_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
                break;
        case LINK_SKIP:
                fts_flags = FTS_PHYSICAL;
                break;
        default:
                fts_flags = FTS_LOGICAL | FTS_NOSTAT;
        }

        fts_flags |= FTS_NOCHDIR;

        fts = fts_open((argv[0] == NULL) ?
            __DECONST(char * const *, wd) : argv, fts_flags, NULL);
        if (fts == NULL)
                err(2, "fts_open");
        while (errno = 0, (p = fts_read(fts)) != NULL) {
                switch (p->fts_info) {
                case FTS_DNR:
                case FTS_ERR:
                case FTS_NS:
                        file_err = true;
                        if(!sflag)
                                warnc(p->fts_errno, "%s", p->fts_path);
                        break;
                case FTS_D:
                        if (dexclude || dinclude)
                                if (!dir_matching(p->fts_name) ||
                                    !dir_matching(p->fts_path))
                                        fts_set(fts, p, FTS_SKIP);
                        break;
                case FTS_DC:
                        /* Print a warning for recursive directory loop */
                        warnx("warning: %s: recursive directory loop",
                            p->fts_path);
                        break;
                case FTS_DP:
                        break;
                case FTS_SL:
                        /*
                         * Skip symlinks for LINK_EXPLICIT and
                         * LINK_SKIP.  Note that due to FTS_COMFOLLOW,
                         * symlinks on the command line are followed
                         * for LINK_EXPLICIT and not reported as
                         * symlinks.
                         */
                        break;
                default:
                        /* Check for file exclusion/inclusion */
                        ok = true;
                        if (fexclude || finclude)
                                ok &= file_matching(p->fts_path);

                        if (ok && procfile(p->fts_path))
                                matched = true;
                        break;
                }
        }
        if (errno != 0)
                err(2, "fts_read");

        fts_close(fts);
        return (matched);
}

static void
procmatch_match(struct mprintc *mc, struct parsec *pc)
{

        if (mc->doctx) {
                if (!first_match && (!mc->same_file || mc->last_outed > 0))
                        printf("--\n");
                if (Bflag > 0)
                        printqueue();
                mc->tail = Aflag;
        }

        /* Print the matching line, but only if not quiet/binary */
        if (mc->printmatch) {
                size_t last_out;
                bool terminated;

                last_out = 0;
                terminated = printline(pc, ':', &last_out);
                while (pc->matchidx >= MAX_MATCHES) {
                        /* Reset matchidx and try again */
                        pc->matchidx = 0;
                        if (procline(pc) == !vflag)
                                terminated = printline(pc, ':', &last_out);
                        else
                                break;
                }

                /*
                 * The above loop processes the entire line as long as we keep
                 * hitting the maximum match count.  At this point, we know
                 * that there's nothing left to be printed and can terminate the
                 * line.
                 */
                if (!terminated)
                        printline(pc, ':', &last_out);

                first_match = false;
                mc->same_file = true;
                mc->last_outed = 0;
        }
}

static void
procmatch_nomatch(struct mprintc *mc, struct parsec *pc)
{

        /* Deal with any -A context as needed */
        if (mc->tail > 0) {
                grep_printline(&pc->ln, '-');
                mc->tail--;
                if (Bflag > 0)
                        clearqueue();
        } else if (Bflag == 0 || (Bflag > 0 && enqueue(&pc->ln)))
                /*
                 * Enqueue non-matching lines for -B context. If we're not
                 * actually doing -B context or if the enqueue resulted in a
                 * line being rotated out, then go ahead and increment
                 * last_outed to signify a gap between context/match.
                 */
                ++mc->last_outed;
}

/*
 * Process any matches in the current parsing context, return a boolean
 * indicating whether we should halt any further processing or not. 'true' to
 * continue processing, 'false' to halt.
 */
static bool
procmatches(struct mprintc *mc, struct parsec *pc, bool matched)
{

        if (mflag && mcount <= 0) {
                /*
                 * We already hit our match count, but we need to keep dumping
                 * lines until we've lost our tail.
                 */
                grep_printline(&pc->ln, '-');
                mc->tail--;
                return (mc->tail != 0);
        }

        /*
         * XXX TODO: This should loop over pc->matches and handle things on a
         * line-by-line basis, setting up a `struct str` as needed.
         */
        /* Deal with any -B context or context separators */
        if (matched) {
                procmatch_match(mc, pc);

                /* Count the matches if we have a match limit */
                if (mflag) {
                        /* XXX TODO: Decrement by number of matched lines */
                        mcount -= 1;
                        if (mcount <= 0)
                                return (mc->tail != 0);
                }
        } else if (mc->doctx)
                procmatch_nomatch(mc, pc);

        return (true);
}

/*
 * Opens a file and processes it.  Each file is processed line-by-line
 * passing the lines to procline().
 */
bool
procfile(const char *fn)
{
        struct parsec pc;
        struct mprintc mc;
        struct file *f;
        struct stat sb;
        mode_t s;
        int lines;
        bool line_matched;

        if (strcmp(fn, "-") == 0) {
                fn = label != NULL ? label : errstr[1];
                f = grep_open(NULL);
        } else {
                if (stat(fn, &sb) == 0) {
                        /* Check if we need to process the file */
                        s = sb.st_mode & S_IFMT;
                        if (dirbehave == DIR_SKIP && s == S_IFDIR)
                                return (false);
                        if (devbehave == DEV_SKIP && (s == S_IFIFO ||
                            s == S_IFCHR || s == S_IFBLK || s == S_IFSOCK))
                                return (false);
                }
                f = grep_open(fn);
        }
        if (f == NULL) {
                file_err = true;
                if (!sflag)
                        warn("%s", fn);
                return (false);
        }

        pc.ln.file = grep_strdup(fn);
        pc.ln.line_no = 0;
        pc.ln.len = 0;
        pc.ln.boff = 0;
        pc.ln.off = -1;
        pc.binary = f->binary;
        pc.cntlines = false;
        memset(&mc, 0, sizeof(mc));
        mc.printmatch = true;
        if ((pc.binary && binbehave == BINFILE_BIN) || cflag || qflag ||
            lflag || Lflag)
                mc.printmatch = false;
        if (mc.printmatch && (Aflag != 0 || Bflag != 0))
                mc.doctx = true;
        if (mc.printmatch && (Aflag != 0 || Bflag != 0 || mflag || nflag))
                pc.cntlines = true;
        mcount = mlimit;

        for (lines = 0; lines == 0 || !(lflag || qflag); ) {
                /*
                 * XXX TODO: We need to revisit this in a chunking world. We're
                 * not going to be doing per-line statistics because of the
                 * overhead involved. procmatches can figure that stuff out as
                 * needed. */
                /* Reset per-line statistics */
                pc.printed = 0;
                pc.matchidx = 0;
                pc.lnstart = 0;
                pc.ln.boff = 0;
                pc.ln.off += pc.ln.len + 1;
                /* XXX TODO: Grab a chunk */
                if ((pc.ln.dat = grep_fgetln(f, &pc)) == NULL ||
                    pc.ln.len == 0)
                        break;

                if (pc.ln.len > 0 && pc.ln.dat[pc.ln.len - 1] == fileeol)
                        --pc.ln.len;
                pc.ln.line_no++;

                /* Return if we need to skip a binary file */
                if (pc.binary && binbehave == BINFILE_SKIP) {
                        grep_close(f);
                        free(pc.ln.file);
                        free(f);
                        return (0);
                }

                if (mflag && mcount <= 0) {
                        /*
                         * Short-circuit, already hit match count and now we're
                         * just picking up any remaining pieces.
                         */
                        if (!procmatches(&mc, &pc, false))
                                break;
                        continue;
                }
                line_matched = procline(&pc) == !vflag;
                if (line_matched)
                        ++lines;

                /* Halt processing if we hit our match limit */
                if (!procmatches(&mc, &pc, line_matched))
                        break;
        }
        if (Bflag > 0)
                clearqueue();
        grep_close(f);

        if (cflag && !qflag) {
                if (!hflag)
                        printf("%s:", pc.ln.file);
                printf("%u\n", lines);
        }
        if (lflag && !qflag && lines != 0)
                printf("%s%c", fn, nullflag ? 0 : '\n');
        if (Lflag && !qflag && lines == 0)
                printf("%s%c", fn, nullflag ? 0 : '\n');
        if (lines != 0 && !cflag && !lflag && !Lflag &&
            binbehave == BINFILE_BIN && f->binary && !qflag)
                printf(errstr[7], fn);

        free(pc.ln.file);
        free(f);
        return (lines != 0);
}

#ifdef WITH_INTERNAL_NOSPEC
/*
 * Internal implementation of literal string search within a string, modeled
 * after regexec(3), for use when the regex(3) implementation doesn't offer
 * either REG_NOSPEC or REG_LITERAL. This does not apply in the default FreeBSD
 * config, but in other scenarios such as building against libgnuregex or on
 * some non-FreeBSD OSes.
 */
static int
litexec(const struct pat *pat, const char *string, size_t nmatch,
    regmatch_t pmatch[])
{
        char *(*strstr_fn)(const char *, const char *);
        char *sub, *subject;
        const char *search;
        size_t idx, n, ofs, stringlen;

        if (cflags & REG_ICASE)
                strstr_fn = strcasestr;
        else
                strstr_fn = strstr;
        idx = 0;
        ofs = pmatch[0].rm_so;
        stringlen = pmatch[0].rm_eo;
        if (ofs >= stringlen)
                return (REG_NOMATCH);
        subject = strndup(string, stringlen);
        if (subject == NULL)
                return (REG_ESPACE);
        for (n = 0; ofs < stringlen;) {
                search = (subject + ofs);
                if ((unsigned long)pat->len > strlen(search))
                        break;
                sub = strstr_fn(search, pat->pat);
                /*
                 * Ignoring the empty string possibility due to context: grep optimizes
                 * for empty patterns and will never reach this point.
                 */
                if (sub == NULL)
                        break;
                ++n;
                /* Fill in pmatch if necessary */
                if (nmatch > 0) {
                        pmatch[idx].rm_so = ofs + (sub - search);
                        pmatch[idx].rm_eo = pmatch[idx].rm_so + pat->len;
                        if (++idx == nmatch)
                                break;
                        ofs = pmatch[idx].rm_so + 1;
                } else
                        /* We only needed to know if we match or not */
                        break;
        }
        free(subject);
        if (n > 0 && nmatch > 0)
                for (n = idx; n < nmatch; ++n)
                        pmatch[n].rm_so = pmatch[n].rm_eo = -1;

        return (n > 0 ? 0 : REG_NOMATCH);
}
#endif /* WITH_INTERNAL_NOSPEC */

#define iswword(x)      (iswalnum((x)) || (x) == L'_')

/*
 * Processes a line comparing it with the specified patterns.  Each pattern
 * is looped to be compared along with the full string, saving each and every
 * match, which is necessary to colorize the output and to count the
 * matches.  The matching lines are passed to printline() to display the
 * appropriate output.
 */
static bool
procline(struct parsec *pc)
{
        regmatch_t pmatch, lastmatch, chkmatch;
        wchar_t wbegin, wend;
        size_t st, nst;
        unsigned int i;
        int r = 0, leflags = eflags;
        size_t startm = 0, matchidx;
        unsigned int retry;
        bool lastmatched, matched;

        matchidx = pc->matchidx;

        /* Null pattern shortcuts. */
        if (matchall) {
                if (xflag && pc->ln.len == 0) {
                        /* Matches empty lines (-x). */
                        return (true);
                } else if (!wflag && !xflag) {
                        /* Matches every line (no -w or -x). */
                        return (true);
                }

                /*
                 * If we only have the NULL pattern, whether we match or not
                 * depends on if we got here with -w or -x.  If either is set,
                 * the answer is no.  If we have other patterns, we'll defer
                 * to them.
                 */
                if (patterns == 0) {
                        return (!(wflag || xflag));
                }
        } else if (patterns == 0) {
                /* Pattern file with no patterns. */
                return (false);
        }

        matched = false;
        st = pc->lnstart;
        nst = 0;
        /* Initialize to avoid a false positive warning from GCC. */
        lastmatch.rm_so = lastmatch.rm_eo = 0;

        /* Loop to process the whole line */
        while (st <= pc->ln.len) {
                lastmatched = false;
                startm = matchidx;
                retry = 0;
                if (st > 0 && pc->ln.dat[st - 1] != fileeol)
                        leflags |= REG_NOTBOL;
                /* Loop to compare with all the patterns */
                for (i = 0; i < patterns; i++) {
                        pmatch.rm_so = st;
                        pmatch.rm_eo = pc->ln.len;
#ifdef WITH_INTERNAL_NOSPEC
                        if (grepbehave == GREP_FIXED)
                                r = litexec(&pattern[i], pc->ln.dat, 1, &pmatch);
                        else
#endif
                        r = regexec(&r_pattern[i], pc->ln.dat, 1, &pmatch,
                            leflags);
                        if (r != 0)
                                continue;
                        /* Check for full match */
                        if (xflag && (pmatch.rm_so != 0 ||
                            (size_t)pmatch.rm_eo != pc->ln.len))
                                continue;
                        /* Check for whole word match */
                        if (wflag) {
                                wbegin = wend = L' ';
                                if (pmatch.rm_so != 0 &&
                                    sscanf(&pc->ln.dat[pmatch.rm_so - 1],
                                    "%lc", &wbegin) != 1)
                                        r = REG_NOMATCH;
                                else if ((size_t)pmatch.rm_eo !=
                                    pc->ln.len &&
                                    sscanf(&pc->ln.dat[pmatch.rm_eo],
                                    "%lc", &wend) != 1)
                                        r = REG_NOMATCH;
                                else if (iswword(wbegin) ||
                                    iswword(wend))
                                        r = REG_NOMATCH;
                                /*
                                 * If we're doing whole word matching and we
                                 * matched once, then we should try the pattern
                                 * again after advancing just past the start of
                                 * the earliest match. This allows the pattern
                                 * to  match later on in the line and possibly
                                 * still match a whole word.
                                 */
                                if (r == REG_NOMATCH &&
                                    (retry == pc->lnstart ||
                                    (unsigned int)pmatch.rm_so + 1 < retry))
                                        retry = pmatch.rm_so + 1;
                                if (r == REG_NOMATCH)
                                        continue;
                        }
                        lastmatched = true;
                        lastmatch = pmatch;

                        if (matchidx == 0)
                                matched = true;

                        /*
                         * Replace previous match if the new one is earlier
                         * and/or longer. This will lead to some amount of
                         * extra work if -o/--color are specified, but it's
                         * worth it from a correctness point of view.
                         */
                        if (matchidx > startm) {
                                chkmatch = pc->matches[matchidx - 1];
                                if (pmatch.rm_so < chkmatch.rm_so ||
                                    (pmatch.rm_so == chkmatch.rm_so &&
                                    (pmatch.rm_eo - pmatch.rm_so) >
                                    (chkmatch.rm_eo - chkmatch.rm_so))) {
                                        pc->matches[matchidx - 1] = pmatch;
                                        nst = pmatch.rm_eo;
                                }
                        } else {
                                /* Advance as normal if not */
                                pc->matches[matchidx++] = pmatch;
                                nst = pmatch.rm_eo;
                        }
                        /* avoid excessive matching - skip further patterns */
                        if ((color == NULL && !oflag) || qflag || lflag ||
                            matchidx >= MAX_MATCHES) {
                                pc->lnstart = nst;
                                lastmatched = false;
                                break;
                        }
                }

                /*
                 * Advance to just past the start of the earliest match, try
                 * again just in case we still have a chance to match later in
                 * the string.
                 */
                if (!lastmatched && retry > pc->lnstart) {
                        st = retry;
                        continue;
                }

                /* XXX TODO: We will need to keep going, since we're chunky */
                /* One pass if we are not recording matches */
                if (!wflag && ((color == NULL && !oflag) || qflag || lflag || Lflag))
                        break;

                /* If we didn't have any matches or REG_NOSUB set */
                if (!lastmatched || (cflags & REG_NOSUB))
                        nst = pc->ln.len;

                if (!lastmatched)
                        /* No matches */
                        break;
                else if (st == nst && lastmatch.rm_so == lastmatch.rm_eo)
                        /* Zero-length match -- advance one more so we don't get stuck */
                        nst++;

                /* Advance st based on previous matches */
                st = nst;
                pc->lnstart = st;
        }

        /* Reflect the new matchidx in the context */
        pc->matchidx = matchidx;
        return matched;
}

/*
 * Safe malloc() for internal use.
 */
void *
grep_malloc(size_t size)
{
        void *ptr;

        if (size == 0)
                return (NULL);
        if ((ptr = malloc(size)) == NULL)
                err(2, "malloc");
        return (ptr);
}

/*
 * Safe calloc() for internal use.
 */
void *
grep_calloc(size_t nmemb, size_t size)
{
        void *ptr;

        if (nmemb == 0 || size == 0)
                return (NULL);
        if ((ptr = calloc(nmemb, size)) == NULL)
                err(2, "calloc");
        return (ptr);
}

/*
 * Safe realloc() for internal use.
 */
void *
grep_realloc(void *ptr, size_t size)
{

        if ((ptr = realloc(ptr, size)) == NULL)
                err(2, "realloc");
        return (ptr);
}

/*
 * Safe strdup() for internal use.
 */
char *
grep_strdup(const char *str)
{
        char *ret;

        if ((ret = strdup(str)) == NULL)
                err(2, "strdup");
        return (ret);
}

/*
 * Print an entire line as-is, there are no inline matches to consider. This is
 * used for printing context.
 */
void grep_printline(struct str *line, int sep) {
        printline_metadata(line, sep);
        fwrite(line->dat, line->len, 1, stdout);
        putchar(fileeol);

        fflush(stdout);
}

static void
printline_metadata(struct str *line, int sep)
{
        bool printsep;

        printsep = false;
        if (!hflag) {
                if (!nullflag) {
                        fputs(line->file, stdout);
                        printsep = true;
                } else {
                        printf("%s", line->file);
                        putchar(0);
                }
        }
        if (nflag) {
                if (printsep)
                        putchar(sep);
                printf("%d", line->line_no);
                printsep = true;
        }
        if (bflag) {
                if (printsep)
                        putchar(sep);
                printf("%lld", (long long)(line->off + line->boff));
                printsep = true;
        }
        if (printsep)
                putchar(sep);
}

/*
 * Prints a matching line according to the command line options.  We need
 * *last_out to be populated on entry in case this is just a continuation of
 * matches within the same line.
 *
 * Returns true if the line was terminated, false if it was not.
 */
static bool
printline(struct parsec *pc, int sep, size_t *last_out)
{
        size_t a = *last_out;
        size_t i, matchidx;
        regmatch_t match;
        bool terminated;

        /*
         * Nearly all paths below will terminate the line by default, but it is
         * avoided in some circumstances in case we don't have the full context
         * available here.
         */
        terminated = true;

        /* If matchall, everything matches but don't actually print for -o */
        if (oflag && matchall)
                return (terminated);

        matchidx = pc->matchidx;

        /* --color and -o */
        if ((oflag || color) && (pc->printed > 0 || matchidx > 0)) {
                /* Only print metadata once per line if --color */
                if (!oflag && pc->printed == 0) {
                        printline_metadata(&pc->ln, sep);
                }
                for (i = 0; i < matchidx; i++) {
                        match = pc->matches[i];
                        /* Don't output zero length matches */
                        if (match.rm_so == match.rm_eo)
                                continue;
                        /*
                         * Metadata is printed on a per-line basis, so every
                         * match gets file metadata with the -o flag.
                         */
                        if (oflag) {
                                pc->ln.boff = match.rm_so;
                                printline_metadata(&pc->ln, sep);
                        } else {
                                fwrite(pc->ln.dat + a, match.rm_so - a, 1,
                                    stdout);
                        }
                        if (color)
                                fprintf(stdout, "\33[%sm\33[K", color);
                        fwrite(pc->ln.dat + match.rm_so,
                            match.rm_eo - match.rm_so, 1, stdout);
                        if (color)
                                fprintf(stdout, "\33[m\33[K");
                        a = match.rm_eo;
                        if (oflag)
                                putchar('\n');
                }

                /*
                 * Don't terminate if we reached the match limit; we may have
                 * other matches on this line to process.
                 */
                *last_out = a;
                if (!oflag && matchidx != MAX_MATCHES) {
                        if (pc->ln.len - a > 0) {
                                fwrite(pc->ln.dat + a, pc->ln.len - a, 1,
                                    stdout);
                                *last_out = pc->ln.len;
                        }
                        putchar('\n');
                        fflush(stdout);
                } else if (!oflag) {
                        /*
                         * -o is terminated on every match output, so this
                         * branch is only designed to capture MAX_MATCHES in a
                         * line which may be a signal to us for a lack of
                         * context.  The caller will know more and call us again
                         * to terminate if it needs to.
                         */
                        terminated = false;
                } else {
                        fflush(stdout);
                }
        } else
                grep_printline(&pc->ln, sep);
        pc->printed++;
        return (terminated);
}