/*      $OpenBSD: grep.c,v 1.68 2025/05/09 00:50:29 schwarze Exp $      */

/*-
 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
 * 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/types.h>
#include <sys/stat.h>
#include <sys/queue.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "grep.h"

/* Flags passed to regcomp() and regexec() */
int      cflags;
int      eflags = REG_STARTEND;

int      matchall;      /* shortcut */
int      patterns, pattern_sz;
char   **pattern;
regex_t *r_pattern;
fastgrep_t *fg_pattern;

/* For regex errors  */
char     re_error[RE_ERROR_BUF + 1];

/* Command-line flags */
int      Aflag;         /* -A x: print x lines trailing each match */
int      Bflag;         /* -B x: print x lines leading each match */
int      Eflag;         /* -E: interpret pattern as extended regexp */
int      Fflag;         /* -F: interpret pattern as list of fixed strings */
int      Hflag;         /* -H: always print filename header */
int      Lflag;         /* -L: only show names of files with no matches */
int      Rflag;         /* -R: recursively search directory trees */
int      Zflag;         /* -Z: decompress input before processing */
int      bflag;         /* -b: show block numbers for each match */
int      cflag;         /* -c: only show a count of matching lines */
int      hflag;         /* -h: don't print filename headers */
int      iflag;         /* -i: ignore case */
int      lflag;         /* -l: only show names of files with matches */
int      mflag;         /* -m x: stop reading the files after x matches */
long long mcount;       /* count for -m */
long long mlimit;       /* requested value for -m */
int      nflag;         /* -n: show line numbers in front of matching lines */
int      oflag;         /* -o: print each match */
int      qflag;         /* -q: quiet mode (don't output anything) */
int      sflag;         /* -s: silent mode (ignore errors) */
int      vflag;         /* -v: only show non-matching lines */
int      wflag;         /* -w: pattern must start and end on word boundaries */
int      xflag;         /* -x: pattern must match entire line */
int      lbflag;        /* --line-buffered */
int      nullflag;      /* --null */
const char *labelname;  /* --label=name */

int binbehave = BIN_FILE_BIN;

enum {
        BIN_OPT = CHAR_MAX + 1,
        HELP_OPT,
        MMAP_OPT,
        LINEBUF_OPT,
        NULL_OPT,
        LABEL_OPT,
};

/* Housekeeping */
int      first;         /* flag whether or not this is our first match */
int      tail;          /* lines left to print */
int      file_err;      /* file reading error */

struct patfile {
        const char              *pf_file;
        SLIST_ENTRY(patfile)     pf_next;
};
SLIST_HEAD(, patfile)            patfilelh;

extern char *__progname;

static void
usage(void)
{
        fprintf(stderr,
#ifdef NOZ
            "usage: %s [-abcEFGHhIiLlnoqRsUVvwx] [-A num] [-B num] [-C[num]]"
#else
            "usage: %s [-abcEFGHhIiLlnoqRsUVvwxZ] [-A num] [-B num] [-C[num]]"
#endif
            " [-e pattern]\n"
            "\t[-f file] [-m num] [--binary-files=value] [--context[=num]]\n"
            "\t[--label=name] [--line-buffered] [--null] [pattern]"
            " [file ...]\n",
            __progname);
        exit(2);
}

#ifdef NOZ
static const char optstr[] = "+0123456789A:B:CEFGHILRUVabce:f:hilm:noqrsuvwxy";
#else
static const char optstr[] = "+0123456789A:B:CEFGHILRUVZabce:f:hilm:noqrsuvwxy";
#endif

static const struct option long_options[] =
{
        {"binary-files",        required_argument,      NULL, BIN_OPT},
        {"help",                no_argument,            NULL, HELP_OPT},
        {"mmap",                no_argument,            NULL, MMAP_OPT},
        {"label",               required_argument,      NULL, LABEL_OPT},
        {"line-buffered",       no_argument,            NULL, LINEBUF_OPT},
        {"null",                no_argument,            NULL, NULL_OPT},
        {"after-context",       required_argument,      NULL, 'A'},
        {"before-context",      required_argument,      NULL, 'B'},
        {"context",             optional_argument,      NULL, 'C'},
        {"devices",             required_argument,      NULL, 'D'},
        {"extended-regexp",     no_argument,            NULL, 'E'},
        {"fixed-strings",       no_argument,            NULL, 'F'},
        {"basic-regexp",        no_argument,            NULL, 'G'},
        {"with-filename",       no_argument,            NULL, 'H'},
        {"binary",              no_argument,            NULL, 'U'},
        {"version",             no_argument,            NULL, 'V'},
        {"text",                no_argument,            NULL, 'a'},
        {"byte-offset",         no_argument,            NULL, 'b'},
        {"count",               no_argument,            NULL, 'c'},
        {"regexp",              required_argument,      NULL, 'e'},
        {"file",                required_argument,      NULL, 'f'},
        {"no-filename",         no_argument,            NULL, 'h'},
        {"ignore-case",         no_argument,            NULL, 'i'},
        {"files-without-match", no_argument,            NULL, 'L'},
        {"files-with-matches",  no_argument,            NULL, 'l'},
        {"max-count",           required_argument,      NULL, 'm'},
        {"line-number",         no_argument,            NULL, 'n'},
        {"quiet",               no_argument,            NULL, 'q'},
        {"silent",              no_argument,            NULL, 'q'},
        {"recursive",           no_argument,            NULL, 'r'},
        {"no-messages",         no_argument,            NULL, 's'},
        {"revert-match",        no_argument,            NULL, 'v'},
        {"word-regexp",         no_argument,            NULL, 'w'},
        {"line-regexp",         no_argument,            NULL, 'x'},
        {"unix-byte-offsets",   no_argument,            NULL, 'u'},
#ifndef NOZ
        {"decompress",          no_argument,            NULL, 'Z'},
#endif
        {NULL,                  no_argument,            NULL, 0}
};


static void
add_pattern(char *pat, size_t len)
{
        if (!xflag && (len == 0 || matchall)) {
                matchall = 1;
                return;
        }
        if (patterns == pattern_sz) {
                pattern_sz *= 2;
                pattern = grep_reallocarray(pattern, ++pattern_sz, sizeof(*pattern));
        }
        if (len > 0 && pat[len - 1] == '\n')
                --len;
        /* pat may not be NUL-terminated */
        if (wflag && !Fflag) {
                int bol = 0, eol = 0, extra;
                if (pat[0] == '^')
                        bol = 1;
                if (len > 0 && pat[len - 1] == '$')
                        eol = 1;
                extra = Eflag ? 2 : 4;
                pattern[patterns] = grep_malloc(len + 15 + extra);
                snprintf(pattern[patterns], len + 15 + extra,
                   "%s[[:<:]]%s%.*s%s[[:>:]]%s",
                    bol ? "^" : "",
                    Eflag ? "(" : "\\(",
                    (int)len - bol - eol, pat + bol,
                    Eflag ? ")" : "\\)",
                    eol ? "$" : "");
                len += 14 + extra;
        } else {
                pattern[patterns] = grep_malloc(len + 1);
                memcpy(pattern[patterns], pat, len);
                pattern[patterns][len] = '\0';
        }
        ++patterns;
}

static void
add_patterns(char *pats)
{
        char *nl;

        while ((nl = strchr(pats, '\n')) != NULL) {
                add_pattern(pats, nl - pats);
                pats = nl + 1;
        }
        add_pattern(pats, strlen(pats));
}

static void
read_patterns(const char *fn)
{
        FILE *f;
        char *line;
        ssize_t len;
        size_t linesize;

        if ((f = fopen(fn, "r")) == NULL)
                err(2, "%s", fn);
        line = NULL;
        linesize = 0;
        while ((len = getline(&line, &linesize, f)) != -1)
                add_pattern(line, *line == '\n' ? 0 : len);
        if (ferror(f))
                err(2, "%s", fn);
        fclose(f);
        free(line);
}

int
main(int argc, char *argv[])
{
        int c, lastc, prevoptind, newarg, i, needpattern, exprs, expr_sz;
        struct patfile *patfile, *pf_next;
        long l;
        char **expr;
        const char *errstr;

        if (pledge("stdio rpath", NULL) == -1)
                err(2, "pledge");

        SLIST_INIT(&patfilelh);
        switch (__progname[0]) {
        case 'e':
                Eflag = 1;
                break;
        case 'f':
                Fflag = 1;
                break;
#ifndef NOZ
        case 'z':
                Zflag = 1;
                switch(__progname[1]) {
                case 'e':
                        Eflag = 1;
                        break;
                case 'f':
                        Fflag = 1;
                        break;
                }
                break;
#endif
        }

        lastc = '\0';
        newarg = 1;
        prevoptind = 1;
        needpattern = 1;
        expr_sz = exprs = 0;
        expr = NULL;
        while ((c = getopt_long(argc, argv, optstr,
                                long_options, NULL)) != -1) {
                switch (c) {
                case '0': case '1': case '2': case '3': case '4':
                case '5': case '6': case '7': case '8': case '9':
                        if (newarg || !isdigit(lastc))
                                Aflag = 0;
                        else if (Aflag > INT_MAX / 10)
                                errx(2, "context out of range");
                        Aflag = Bflag = (Aflag * 10) + (c - '0');
                        break;
                case 'A':
                case 'B':
                        l = strtonum(optarg, 1, INT_MAX, &errstr);
                        if (errstr != NULL)
                                errx(2, "context %s", errstr);
                        if (c == 'A')
                                Aflag = (int)l;
                        else
                                Bflag = (int)l;
                        break;
                case 'C':
                        if (optarg == NULL)
                                Aflag = Bflag = 2;
                        else {
                                l = strtonum(optarg, 1, INT_MAX, &errstr);
                                if (errstr != NULL)
                                        errx(2, "context %s", errstr);
                                Aflag = Bflag = (int)l;
                        }
                        break;
                case 'E':
                        Fflag = 0;
                        Eflag = 1;
                        break;
                case 'F':
                        Eflag = 0;
                        Fflag = 1;
                        break;
                case 'G':
                        Eflag = Fflag = 0;
                        break;
                case 'H':
                        Hflag = 1;
                        break;
                case 'I':
                        binbehave = BIN_FILE_SKIP;
                        break;
                case 'L':
                        lflag = 0;
                        Lflag = qflag = 1;
                        break;
                case 'R':
                case 'r':
                        Rflag = 1;
                        break;
                case 'U':
                        binbehave = BIN_FILE_BIN;
                        break;
                case 'V':
                        fprintf(stderr, "grep version %u.%u\n", VER_MAJ, VER_MIN);
                        exit(0);
                        break;
#ifndef NOZ
                case 'Z':
                        Zflag = 1;
                        break;
#endif
                case 'a':
                        binbehave = BIN_FILE_TEXT;
                        break;
                case 'b':
                        bflag = 1;
                        break;
                case 'c':
                        cflag = 1;
                        break;
                case 'e':
                        /* defer adding of expressions until all arguments are parsed */
                        if (exprs == expr_sz) {
                                expr_sz *= 2;
                                expr = grep_reallocarray(expr, ++expr_sz,
                                    sizeof(*expr));
                        }
                        needpattern = 0;
                        expr[exprs] = optarg;
                        ++exprs;
                        break;
                case 'f':
                        patfile = grep_malloc(sizeof(*patfile));
                        patfile->pf_file = optarg;
                        SLIST_INSERT_HEAD(&patfilelh, patfile, pf_next);
                        needpattern = 0;
                        break;
                case 'h':
                        hflag = 1;
                        break;
                case 'i':
                case 'y':
                        iflag = 1;
                        cflags |= REG_ICASE;
                        break;
                case 'l':
                        Lflag = 0;
                        lflag = qflag = 1;
                        break;
                case 'm':
                        mflag = 1;
                        mlimit = mcount = strtonum(optarg, 0, LLONG_MAX,
                           &errstr);
                        if (errstr != NULL)
                                errx(2, "invalid max-count %s: %s",
                                    optarg, errstr);
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 'o':
                        oflag = 1;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                case 'v':
                        vflag = 1;
                        break;
                case 'w':
                        wflag = 1;
                        break;
                case 'x':
                        xflag = 1;
                        break;
                case BIN_OPT:
                        if (strcmp("binary", optarg) == 0)
                                binbehave = BIN_FILE_BIN;
                        else if (strcmp("without-match", optarg) == 0)
                                binbehave = BIN_FILE_SKIP;
                        else if (strcmp("text", optarg) == 0)
                                binbehave = BIN_FILE_TEXT;
                        else
                                errx(2, "Unknown binary-files option");
                        break;
                case 'u':
                case MMAP_OPT:
                        /* default, compatibility */
                        break;
                case LABEL_OPT:
                        labelname = optarg;
                        break;
                case LINEBUF_OPT:
                        lbflag = 1;
                        break;
                case NULL_OPT:
                        nullflag = 1;
                        break;
                case HELP_OPT:
                default:
                        usage();
                }
                lastc = c;
                newarg = optind != prevoptind;
                prevoptind = optind;
        }
        argc -= optind;
        argv += optind;

        for (i = 0; i < exprs; i++)
                add_patterns(expr[i]);
        free(expr);
        expr = NULL;

        for (patfile = SLIST_FIRST(&patfilelh); patfile != NULL;
            patfile = pf_next) {
                pf_next = SLIST_NEXT(patfile, pf_next);
                read_patterns(patfile->pf_file);
                free(patfile);
        }

        if (argc == 0 && needpattern)
                usage();

        if (argc != 0 && needpattern) {
                add_patterns(*argv);
                --argc;
                ++argv;
        }
        if (argc == 1 && strcmp(*argv, "-") == 0) {
                /* stdin */
                --argc;
                ++argv;
        }

        if (Eflag)
                cflags |= REG_EXTENDED;
        if (Fflag)
                cflags |= REG_NOSPEC;
#ifdef SMALL
        /* Sorry, this won't work */
        if (Fflag && wflag)
                errx(1, "Can't use small fgrep with -w");
#endif
        fg_pattern = grep_calloc(patterns, sizeof(*fg_pattern));
        r_pattern = grep_calloc(patterns, sizeof(*r_pattern));
        for (i = 0; i < patterns; ++i) {
                /* Check if cheating is allowed (always is for fgrep). */
#ifndef SMALL
                if (Fflag) {
                        fgrepcomp(&fg_pattern[i], pattern[i]);
                } else
#endif
                {
                        if (fastcomp(&fg_pattern[i], pattern[i])) {
                                /* Fall back to full regex library */
                                c = regcomp(&r_pattern[i], pattern[i], cflags);
                                if (c != 0) {
                                        regerror(c, &r_pattern[i], re_error,
                                            RE_ERROR_BUF);
                                        errx(2, "%s", re_error);
                                }
                        }
                }
        }

        if (lbflag)
                setvbuf(stdout, NULL, _IOLBF, 0);

        if ((argc == 0 || argc == 1) && !Rflag && !Hflag)
                hflag = 1;

        if (argc == 0 && !Rflag)
                exit(!procfile(NULL));

        if (Rflag)
                c = grep_tree(argv);
        else
                for (c = 0; argc--; ++argv)
                        c |= procfile(*argv);

        exit(c ? (file_err ? (qflag ? 0 : 2) : 0) : (file_err ? 2 : 1));
}