usr/src/lib/libc/gen/glob.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)glob.c      5.12 (Berkeley) 6/24/91";
#endif /* LIBC_SCCS and not lint */

/*
 * glob(3) -- a superset of the one defined in POSIX 1003.2.
 *
 * The [!...] convention to negate a range is supported (SysV, Posix, ksh).
 *
 * Optional extra services, controlled by flags not defined by POSIX:
 *
 * GLOB_QUOTE:
 *      Escaping convention: \ inhibits any special meaning the following
 *      character might have (except \ at end of string is retained).
 * GLOB_MAGCHAR:
 *      Set in gl_flags if pattern contained a globbing character.
 * gl_matchc:
 *      Number of matches in the current invocation of glob.
 */

#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <dirent.h>
#include <glob.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#define DOLLAR          '$'
#define DOT             '.'
#define EOS             '\0'
#define LBRACKET        '['
#define NOT             '!'
#define QUESTION        '?'
#define QUOTE           '\\'
#define RANGE           '-'
#define RBRACKET        ']'
#define SEP             '/'
#define STAR            '*'
#define TILDE           '~'
#define UNDERSCORE      '_'

#define M_QUOTE         0x8000
#define M_PROTECT       0x4000
#define M_MASK          0xffff
#define M_ASCII         0x00ff

#define CHAR(c)         ((c)&M_ASCII)
#define META(c)         ((c)|M_QUOTE)
#define M_ALL           META('*')
#define M_END           META(']')
#define M_NOT           META('!')
#define M_ONE           META('?')
#define M_RNG           META('-')
#define M_SET           META('[')
#define ismeta(c)       (((c)&M_QUOTE) != 0)

typedef u_short Char;

static int       compare __P((const void *, const void *));
static void      g_Ctoc __P((Char *, char *));
static int       g_lstat __P((Char *, struct stat *));
static DIR      *g_opendir __P((Char *));
static Char     *g_strchr __P((Char *, int));
static int       g_stat __P((Char *, struct stat *));
static int       glob1 __P((Char *, glob_t *));
static int       glob2 __P((Char *, Char *, Char *, glob_t *));
static int       glob3 __P((Char *, Char *, Char *, Char *, glob_t *));
static int       globextend __P((Char *, glob_t *));
static int       match __P((Char *, Char *, Char *));
#ifdef DEBUG
static void      qprintf __P((Char *));
#endif

/*
 * The main glob() routine: compiles the pattern (optionally processing
 * quotes), calls glob1() to do the real pattern matching, and finally
 * sorts the list (unless unsorted operation is requested).  Returns 0
 * if things went well, nonzero if errors occurred.  It is not an error
 * to find no matches.
 */
glob(pattern, flags, errfunc, pglob)
        const char *pattern;
        int flags, (*errfunc) __P((char *, int));
        glob_t *pglob;
{
        const u_char *compilepat, *patnext;
        int c, err, oldpathc;
        Char *bufnext, *bufend, *compilebuf, *qpatnext, patbuf[MAXPATHLEN+1];

        patnext = (u_char *) pattern;
        if (!(flags & GLOB_APPEND)) {
                pglob->gl_pathc = 0;
                pglob->gl_pathv = NULL;
                if (!(flags & GLOB_DOOFFS))
                        pglob->gl_offs = 0;
        }
        pglob->gl_flags = flags & ~GLOB_MAGCHAR;
        pglob->gl_errfunc = errfunc;
        oldpathc = pglob->gl_pathc;
        pglob->gl_matchc = 0;

        bufnext = patbuf;
        bufend = bufnext + MAXPATHLEN;
        compilebuf = bufnext;
        compilepat = patnext;
        if (flags & GLOB_QUOTE) {
                /* Protect the quoted characters. */
                while (bufnext < bufend && (c = *patnext++) != EOS)
                        if (c == QUOTE) {
                                if ((c = *patnext++) == EOS) {
                                        c = QUOTE;
                                        --patnext;
                                }
                                *bufnext++ = c | M_PROTECT;
                        }
                        else
                                *bufnext++ = c;
        }
        else
            while (bufnext < bufend && (c = *patnext++) != EOS)
                    *bufnext++ = c;
        *bufnext = EOS;

        bufnext = patbuf;
        qpatnext = patbuf;
        /* We don't need to check for buffer overflow any more. */
        while ((c = *qpatnext++) != EOS) {
                switch (c) {
                case LBRACKET:
                        pglob->gl_flags |= GLOB_MAGCHAR;
                        c = *qpatnext;
                        if (c == NOT)
                                ++qpatnext;
                        if (*qpatnext == EOS ||
                            g_strchr(qpatnext+1, RBRACKET) == NULL) {
                                *bufnext++ = LBRACKET;
                                if (c == NOT)
                                        --qpatnext;
                                break;
                        }
                        *bufnext++ = M_SET;
                        if (c == NOT)
                                *bufnext++ = M_NOT;
                        c = *qpatnext++;
                        do {
                                *bufnext++ = CHAR(c);
                                if (*qpatnext == RANGE &&
                                    (c = qpatnext[1]) != RBRACKET) {
                                        *bufnext++ = M_RNG;
                                        *bufnext++ = CHAR(c);
                                        qpatnext += 2;
                                }
                        } while ((c = *qpatnext++) != RBRACKET);
                        *bufnext++ = M_END;
                        break;
                case QUESTION:
                        pglob->gl_flags |= GLOB_MAGCHAR;
                        *bufnext++ = M_ONE;
                        break;
                case STAR:
                        pglob->gl_flags |= GLOB_MAGCHAR;
                        *bufnext++ = M_ALL;
                        break;
                default:
                        *bufnext++ = CHAR(c);
                        break;
                }
        }
        *bufnext = EOS;
#ifdef DEBUG
        qprintf(patbuf);
#endif

        if ((err = glob1(patbuf, pglob)) != 0)
                return(err);

        if (pglob->gl_pathc == oldpathc && flags & GLOB_NOCHECK) {
                if (!(flags & GLOB_QUOTE)) {
                        Char *dp = compilebuf;
                        const u_char *sp = compilepat;
                        while (*dp++ = *sp++);
                }
                else {
                        /*
                         * Copy pattern, interpreting quotes; this is slightly
                         * different than the interpretation of quotes above
                         * -- which should prevail?
                         */
                        while (*compilepat != EOS) {
                                if (*compilepat == QUOTE) {
                                        if (*++compilepat == EOS)
                                                --compilepat;
                                }
                                *compilebuf++ = (u_char)*compilepat++;
                        }
                        *compilebuf = EOS;
                }
                return(globextend(patbuf, pglob));
        } else if (!(flags & GLOB_NOSORT))
                qsort(pglob->gl_pathv + pglob->gl_offs + oldpathc,
                    pglob->gl_pathc - oldpathc, sizeof(char *), compare);
        return(0);
}

static int
compare(p, q)
        const void *p, *q;
{
        return(strcmp(*(char **)p, *(char **)q));
}

static
glob1(pattern, pglob)
        Char *pattern;
        glob_t *pglob;
{
        Char pathbuf[MAXPATHLEN+1];

        /* A null pathname is invalid -- POSIX 1003.1 sect. 2.4. */
        if (*pattern == EOS)
                return(0);
        return(glob2(pathbuf, pathbuf, pattern, pglob));
}

/*
 * The functions glob2 and glob3 are mutually recursive; there is one level
 * of recursion for each segment in the pattern that contains one or more
 * meta characters.
 */
static
glob2(pathbuf, pathend, pattern, pglob)
        Char *pathbuf, *pathend, *pattern;
        glob_t *pglob;
{
        struct stat sb;
        Char *p, *q;
        int anymeta;

        /*
         * Loop over pattern segments until end of pattern or until
         * segment with meta character found.
         */
        for (anymeta = 0;;) {
                if (*pattern == EOS) {          /* End of pattern? */
                        *pathend = EOS;
                        if (g_stat(pathbuf, &sb))
                                return(0);

                        if (((pglob->gl_flags & GLOB_MARK) &&
                            pathend[-1] != SEP) && (S_ISDIR(sb.st_mode)
                            || (S_ISLNK(sb.st_mode) &&
                            (g_stat(pathbuf, &sb) == 0) &&
                            S_ISDIR(sb.st_mode)))) {
                                *pathend++ = SEP;
                                *pathend = EOS;
                        }
                        ++pglob->gl_matchc;
                        return(globextend(pathbuf, pglob));
                }

                /* Find end of next segment, copy tentatively to pathend. */
                q = pathend;
                p = pattern;
                while (*p != EOS && *p != SEP) {
                        if (ismeta(*p))
                                anymeta = 1;
                        *q++ = *p++;
                }

                if (!anymeta) {         /* No expansion, do next segment. */
                        pathend = q;
                        pattern = p;
                        while (*pattern == SEP)
                                *pathend++ = *pattern++;
                } else                  /* Need expansion, recurse. */
                        return(glob3(pathbuf, pathend, pattern, p, pglob));
        }
        /* NOTREACHED */
}

static
glob3(pathbuf, pathend, pattern, restpattern, pglob)
        Char *pathbuf, *pathend, *pattern, *restpattern;
        glob_t *pglob;
{
        register struct dirent *dp;
        DIR *dirp;
        int len, err;

        *pathend = EOS;
        errno = 0;

        if (!(dirp = g_opendir(pathbuf)))
                /* TODO: don't call for ENOENT or ENOTDIR? */
                if (pglob->gl_errfunc &&
                    (*pglob->gl_errfunc)(pathbuf, errno) ||
                    (pglob->gl_flags & GLOB_ERR))
                        return(GLOB_ABEND);
                else
                        return(0);

        err = 0;

        /* Search directory for matching names. */
        while ((dp = readdir(dirp))) {
                register u_char *sc;
                register Char *dc;

                /* Initial DOT must be matched literally. */
                if (dp->d_name[0] == DOT && *pattern != DOT)
                        continue;
                for (sc = (u_char *) dp->d_name, dc = pathend;
                     *dc++ = *sc++;);
                if (!match(pathend, pattern, restpattern)) {
                        *pathend = EOS;
                        continue;
                }
                err = glob2(pathbuf, --dc, restpattern, pglob);
                if (err)
                        break;
        }

        /* TODO: check error from readdir? */
        (void)closedir(dirp);
        return(err);
}


/*
 * Extend the gl_pathv member of a glob_t structure to accomodate a new item,
 * add the new item, and update gl_pathc.
 *
 * This assumes the BSD realloc, which only copies the block when its size
 * crosses a power-of-two boundary; for v7 realloc, this would cause quadratic
 * behavior.
 *
 * Return 0 if new item added, error code if memory couldn't be allocated.
 *
 * Invariant of the glob_t structure:
 *      Either gl_pathc is zero and gl_pathv is NULL; or gl_pathc > 0 and
 *      gl_pathv points to (gl_offs + gl_pathc + 1) items.
 */
static int
globextend(path, pglob)
        Char *path;
        glob_t *pglob;
{
        register char **pathv;
        register int i;
        u_int newsize;
        char *copy;
        Char *p;

        newsize = sizeof(*pathv) * (2 + pglob->gl_pathc + pglob->gl_offs);
        pathv = (char **)realloc((char *)pglob->gl_pathv, newsize);
        if (pathv == NULL)
                return(GLOB_NOSPACE);

        if (pglob->gl_pathv == NULL && pglob->gl_offs > 0) {
                /* first time around -- clear initial gl_offs items */
                pathv += pglob->gl_offs;
                for (i = pglob->gl_offs; --i >= 0; )
                        *--pathv = NULL;
        }
        pglob->gl_pathv = pathv;

        for (p = path; *p++;);
        if ((copy = malloc(p - path)) != NULL) {
                g_Ctoc(path, copy);
                pathv[pglob->gl_offs + pglob->gl_pathc++] = copy;
        }
        pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
        return(copy == NULL ? GLOB_NOSPACE : 0);
}


/*
 * pattern matching function for filenames.  Each occurrence of the *
 * pattern causes a recursion level.
 */
static
match(name, pat, patend)
        register Char *name, *pat, *patend;
{
        int ok, negate_range;
        Char c, k;

        while (pat < patend) {
                c = *pat++;
                switch (c & M_MASK) {
                case M_ALL:
                        if (pat == patend)
                                return(1);
                        for (; *name != EOS; ++name)
                                if (match(name, pat, patend))
                                        return(1);
                        return(0);
                case M_ONE:
                        if (*name++ == EOS)
                                return(0);
                        break;
                case M_SET:
                        ok = 0;
                        k = *name++;
                        if (negate_range = ((*pat & M_MASK) == M_NOT))
                                ++pat;
                        while (((c = *pat++) & M_MASK) != M_END)
                                if ((*pat & M_MASK) == M_RNG) {
                                        if (c <= k && k <= pat[1])
                                                ok = 1;
                                        pat += 2;
                                } else if (c == k)
                                        ok = 1;
                        if (ok == negate_range)
                                return(0);
                        break;
                default:
                        if (*name++ != c)
                                return(0);
                        break;
                }
        }
        return(*name == EOS);
}

/* Free allocated data belonging to a glob_t structure. */
void
globfree(pglob)
        glob_t *pglob;
{
        register int i;
        register char **pp;

        if (pglob->gl_pathv != NULL) {
                pp = pglob->gl_pathv + pglob->gl_offs;
                for (i = pglob->gl_pathc; i--; ++pp)
                        if (*pp)
                                free(*pp);
                free(pglob->gl_pathv);
        }
}

static DIR *
g_opendir(str)
        register Char *str;
{
        char buf[MAXPATHLEN];

        if (!*str)
                return(opendir("."));
        g_Ctoc(str, buf);
        return(opendir(buf));
}

static int
g_lstat(fn, sb)
        register Char *fn;
        struct stat *sb;
{
        char buf[MAXPATHLEN];

        g_Ctoc(fn, buf);
        return(lstat(buf, sb));
}

static int
g_stat(fn, sb)
        register Char *fn;
        struct stat *sb;
{
        char buf[MAXPATHLEN];

        g_Ctoc(fn, buf);
        return(stat(buf, sb));
}

static Char *
g_strchr(str, ch)
        Char *str;
        int ch;
{
        do {
                if (*str == ch)
                        return (str);
        } while (*str++);
        return (NULL);
}

static void
g_Ctoc(str, buf)
        register Char *str;
        char *buf;
{
        register char *dc;

        for (dc = buf; *dc++ = *str++;);
}

#ifdef DEBUG
static void
qprintf(s)
        register Char *s;
{
        register Char *p;

        for (p = s; *p; p++)
                (void)printf("%c", *p & 0xff);
        (void)printf("\n");
        for (p = s; *p; p++)
                (void)printf("%c", *p & M_PROTECT ? '"' : ' ');
        (void)printf("\n");
        for (p = s; *p; p++)
                (void)printf("%c", *p & M_META ? '_' : ' ');
        (void)printf("\n");
}
#endif