root/usr.bin/find/find.c
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Cimarron D. Taylor of the University of California, Berkeley.
 *
 * 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/types.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fts.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "find.h"

static int find_compare(const FTSENT * const *s1, const FTSENT * const *s2);

/*
 * find_compare --
 *      tell fts_open() how to order the traversal of the hierarchy. 
 *      This variant gives lexicographical order, i.e., alphabetical
 *      order within each directory.
 */
static int
find_compare(const FTSENT * const *s1, const FTSENT * const *s2)
{

        return (strcoll((*s1)->fts_name, (*s2)->fts_name));
}

/*
 * find_formplan --
 *      process the command line and create a "plan" corresponding to the
 *      command arguments.
 */
PLAN *
find_formplan(char *argv[])
{
        PLAN *plan, *tail, *new;

        /*
         * for each argument in the command line, determine what kind of node
         * it is, create the appropriate node type and add the new plan node
         * to the end of the existing plan.  The resulting plan is a linked
         * list of plan nodes.  For example, the string:
         *
         *      % find . -name foo -newer bar -print
         *
         * results in the plan:
         *
         *      [-name foo]--> [-newer bar]--> [-print]
         *
         * in this diagram, `[-name foo]' represents the plan node generated
         * by c_name() with an argument of foo and `-->' represents the
         * plan->next pointer.
         */
        for (plan = tail = NULL; *argv;) {
                if (!(new = find_create(&argv)))
                        continue;
                if (plan == NULL)
                        tail = plan = new;
                else {
                        tail->next = new;
                        tail = new;
                }
        }

        /*
         * if the user didn't specify one of -print, -ok or -exec, then -print
         * is assumed so we bracket the current expression with parens, if
         * necessary, and add a -print node on the end.
         */
        if (!isoutput) {
                OPTION *p;
                char **argv1 = 0;

                if (plan == NULL) {
                        p = lookup_option("-print");
                        new = (p->create)(p, &argv1);
                        tail = plan = new;
                } else {
                        p = lookup_option("(");
                        new = (p->create)(p, &argv1);
                        new->next = plan;
                        plan = new;
                        p = lookup_option(")");
                        new = (p->create)(p, &argv1);
                        tail->next = new;
                        tail = new;
                        p = lookup_option("-print");
                        new = (p->create)(p, &argv1);
                        tail->next = new;
                        tail = new;
                }
        }

        /*
         * the command line has been completely processed into a search plan
         * except for the (, ), !, and -o operators.  Rearrange the plan so
         * that the portions of the plan which are affected by the operators
         * are moved into operator nodes themselves.  For example:
         *
         *      [!]--> [-name foo]--> [-print]
         *
         * becomes
         *
         *      [! [-name foo] ]--> [-print]
         *
         * and
         *
         *      [(]--> [-depth]--> [-name foo]--> [)]--> [-print]
         *
         * becomes
         *
         *      [expr [-depth]-->[-name foo] ]--> [-print]
         *
         * operators are handled in order of precedence.
         */

        plan = paren_squish(plan);              /* ()'s */
        plan = not_squish(plan);                /* !'s */
        plan = or_squish(plan);                 /* -o's */
        return (plan);
}

FTS *tree;                      /* pointer to top of FTS hierarchy */

/*
 * find_execute --
 *      take a search plan and an array of search paths and executes the plan
 *      over all FTSENT's returned for the given search paths.
 */
int
find_execute(PLAN *plan, char *paths[])
{
        FTSENT *entry;
        PLAN *p;
        size_t counter = 0;
        int e;

        tree = fts_open(paths, ftsoptions, (issort ? find_compare : NULL));
        if (tree == NULL)
                err(1, "ftsopen");

        exitstatus = 0;
        while (errno = 0, (entry = fts_read(tree)) != NULL) {
                if (maxdepth != -1 && entry->fts_level >= maxdepth) {
                        if (fts_set(tree, entry, FTS_SKIP))
                                err(1, "%s", entry->fts_path);
                }

                switch (entry->fts_info) {
                case FTS_D:
                        if (isdepth)
                                continue;
                        break;
                case FTS_DP:
                        if (!isdepth)
                                continue;
                        break;
                case FTS_DNR:
                case FTS_NS:
                        if (ignore_readdir_race &&
                            entry->fts_errno == ENOENT && entry->fts_level > 0)
                                continue;
                        /* FALLTHROUGH */
                case FTS_ERR:
                        (void)fflush(stdout);
                        warnx("%s: %s",
                            entry->fts_path, strerror(entry->fts_errno));
                        exitstatus = 1;
                        continue;
#if defined(FTS_W) && defined(FTS_WHITEOUT)
                case FTS_W:
                        if (ftsoptions & FTS_WHITEOUT)
                                break;
                        continue;
#endif /* FTS_W */
                }

                if (showinfo) {
                        fprintf(stderr, "Scanning: %s\n", entry->fts_path);
                        fprintf(stderr, "Scanned: %zu\n\n", counter);
                        showinfo = 0;
                }
                ++counter;

#define BADCH   " \t\n\\'\""
                if (isxargs && strpbrk(entry->fts_path, BADCH)) {
                        (void)fflush(stdout);
                        warnx("%s: illegal path", entry->fts_path);
                        exitstatus = 1;
                        continue;
                }

                if (mindepth != -1 && entry->fts_level < mindepth)
                        continue;

                /*
                 * Call all the functions in the execution plan until one is
                 * false or all have been executed.  This is where we do all
                 * the work specified by the user on the command line.
                 */
                for (p = plan; p && (p->execute)(p, entry); p = p->next);
        }
        e = errno;
        finish_execplus();
        if (e && (!ignore_readdir_race || e != ENOENT))
                errc(1, e, "fts_read");
        return (exitstatus);
}