cosmopolitan/third_party/regex/glob.c.todo

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8                                :vi│
╚─────────────────────────────────────────────────────────────────────────────*/
/* clang-format off */

/*
  Musl Libc
  Copyright © 2005-2014 Rich Felker, et al.

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#define _BSD_SOURCE
#include <dirent.h>
#include <errno.h>
#include <fnmatch.h>
#include <glob.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

asm(".ident\t\"\\n\\n\
Musl Libc » glob (MIT License)\\n\
Copyright 2005-2014 Rich Felker\"");

struct match
{
	struct match *next;
	char name[];
};

static int append(struct match **tail, const char *name, size_t len, int mark)
{
	struct match *new = malloc(sizeof(struct match) + len + 2);
	if (!new) return -1;
	(*tail)->next = new;
	new->next = NULL;
	memcpy(new->name, name, len+1);
	if (mark && len && name[len-1]!='/') {
		new->name[len] = '/';
		new->name[len+1] = 0;
	}
	*tail = new;
	return 0;
}

static int do_glob(char *buf, size_t pos, int type, char *pat, int flags, int (*errfunc)(const char *path, int err), struct match **tail)
{
	/* If GLOB_MARK is unused, we don't care about type. */
	if (!type && !(flags & GLOB_MARK)) type = DT_REG;

	/* Special-case the remaining pattern being all slashes, in
	 * which case we can use caller-passed type if it's a dir. */
	if (*pat && type!=DT_DIR) type = 0;
	while (pos+1 < PATH_MAX && *pat=='/') buf[pos++] = *pat++;

	/* Consume maximal [escaped-]literal prefix of pattern, copying
	 * and un-escaping it to the running buffer as we go. */
	ptrdiff_t i=0, j=0;
	int in_bracket = 0, overflow = 0;
	for (; pat[i]!='*' && pat[i]!='?' && (!in_bracket || pat[i]!=']'); i++) {
		if (!pat[i]) {
			if (overflow) return 0;
			pat += i;
			pos += j;
			i = j = 0;
			break;
		} else if (pat[i] == '[') {
			in_bracket = 1;
		} else if (pat[i] == '\\' && !(flags & GLOB_NOESCAPE)) {
			/* Backslashes inside a bracket are (at least by
			 * our interpretation) non-special, so if next
			 * char is ']' we have a complete expression. */
			if (in_bracket && pat[i+1]==']') break;
			/* Unpaired final backslash never matches. */
			if (!pat[i+1]) return 0;
			i++;
		}
		if (pat[i] == '/') {
			if (overflow) return 0;
			in_bracket = 0;
			pat += i+1;
			i = -1;
			pos += j+1;
			j = -1;
		}
		/* Only store a character if it fits in the buffer, but if
		 * a potential bracket expression is open, the overflow
		 * must be remembered and handled later only if the bracket
		 * is unterminated (and thereby a literal), so as not to
		 * disallow long bracket expressions with short matches. */
		if (pos+(j+1) < PATH_MAX) {
			buf[pos+j++] = pat[i];
		} else if (in_bracket) {
			overflow = 1;
		} else {
			return 0;
		}
		/* If we consume any new components, the caller-passed type
		 * or dummy type from above is no longer valid. */
		type = 0;
	}
	buf[pos] = 0;
	if (!*pat) {
		/* If we consumed any components above, or if GLOB_MARK is
		 * requested and we don't yet know if the match is a dir,
		 * we must call stat to confirm the file exists and/or
		 * determine its type. */
		struct stat st;
		if ((flags & GLOB_MARK) && type==DT_LNK) type = 0;
		if (!type && stat(buf, &st)) {
			if (errno!=ENOENT && (errfunc(buf, errno) || (flags & GLOB_ERR)))
				return GLOB_ABORTED;
			return 0;
		}
		if (!type && S_ISDIR(st.st_mode)) type = DT_DIR;
		if (append(tail, buf, pos, (flags & GLOB_MARK) && type==DT_DIR))
			return GLOB_NOSPACE;
		return 0;
	}
	char *p2 = strchr(pat, '/'), saved_sep = '/';
	/* Check if the '/' was escaped and, if so, remove the escape char
	 * so that it will not be unpaired when passed to fnmatch. */
	if (p2 && !(flags & GLOB_NOESCAPE)) {
		char *p;
		for (p=p2; p>pat && p[-1]=='\\'; p--);
		if ((p2-p)%2) {
			p2--;
			saved_sep = '\\';
		}
	}
	DIR *dir = opendir(pos ? buf : ".");
	if (!dir) {
		if (errfunc(buf, errno) || (flags & GLOB_ERR))
			return GLOB_ABORTED;
		return 0;
	}
	int old_errno = errno;
	struct dirent *de;
	while (errno=0, de=readdir(dir)) {
		/* Quickly skip non-directories when there's pattern left. */
		if (p2 && de->d_type && de->d_type!=DT_DIR && de->d_type!=DT_LNK)
			continue;

		size_t l = strlen(de->d_name);
		if (l >= PATH_MAX-pos) continue;

		if (p2) *p2 = 0;

		int fnm_flags= ((flags & GLOB_NOESCAPE) ? FNM_NOESCAPE : 0)
			| ((!(flags & GLOB_PERIOD)) ? FNM_PERIOD : 0);

		if (fnmatch(pat, de->d_name, fnm_flags))
			continue;

		/* With GLOB_PERIOD, don't allow matching . or .. unless
		 * fnmatch would match them with FNM_PERIOD rules in effect. */
		if (p2 && (flags & GLOB_PERIOD) && de->d_name[0]=='.'
		    && (!de->d_name[1] || de->d_name[1]=='.' && !de->d_name[2])
		    && fnmatch(pat, de->d_name, fnm_flags | FNM_PERIOD))
			continue;

		memcpy(buf+pos, de->d_name, l+1);
		if (p2) *p2 = saved_sep;
		int r = do_glob(buf, pos+l, de->d_type, p2 ? p2 : "", flags, errfunc, tail);
		if (r) {
			closedir(dir);
			return r;
		}
	}
	int readerr = errno;
	if (p2) *p2 = saved_sep;
	closedir(dir);
	if (readerr && (errfunc(buf, errno) || (flags & GLOB_ERR)))
		return GLOB_ABORTED;
	errno = old_errno;
	return 0;
}

static int ignore_err(const char *path, int err)
{
	return 0;
}

static void freelist(struct match *head)
{
	struct match *match, *next;
	for (match=head->next; match; match=next) {
		next = match->next;
		free(match);
	}
}

static int sort(const void *a, const void *b)
{
	return strcmp(*(const char **)a, *(const char **)b);
}

int glob(const char *restrict pat, int flags, int (*errfunc)(const char *path, int err), glob_t *restrict g)
{
	struct match head = { .next = NULL }, *tail = &head;
	size_t cnt, i;
	size_t offs = (flags & GLOB_DOOFFS) ? g->gl_offs : 0;
	int error = 0;
	char buf[PATH_MAX];
	
	if (!errfunc) errfunc = ignore_err;

	if (!(flags & GLOB_APPEND)) {
		g->gl_offs = offs;
		g->gl_pathc = 0;
		g->gl_pathv = NULL;
	}

	if (*pat) {
		char *p = strdup(pat);
		if (!p) return GLOB_NOSPACE;
		buf[0] = 0;
		error = do_glob(buf, 0, 0, p, flags, errfunc, &tail);
		free(p);
	}

	if (error == GLOB_NOSPACE) {
		freelist(&head);
		return error;
	}
	
	for (cnt=0, tail=head.next; tail; tail=tail->next, cnt++);
	if (!cnt) {
		if (flags & GLOB_NOCHECK) {
			tail = &head;
			if (append(&tail, pat, strlen(pat), 0))
				return GLOB_NOSPACE;
			cnt++;
		} else
			return GLOB_NOMATCH;
	}

	if (flags & GLOB_APPEND) {
		char **pathv = realloc(g->gl_pathv, (offs + g->gl_pathc + cnt + 1) * sizeof(char *));
		if (!pathv) {
			freelist(&head);
			return GLOB_NOSPACE;
		}
		g->gl_pathv = pathv;
		offs += g->gl_pathc;
	} else {
		g->gl_pathv = malloc((offs + cnt + 1) * sizeof(char *));
		if (!g->gl_pathv) {
			freelist(&head);
			return GLOB_NOSPACE;
		}
		for (i=0; i<offs; i++)
			g->gl_pathv[i] = NULL;
	}
	for (i=0, tail=head.next; i<cnt; tail=tail->next, i++)
		g->gl_pathv[offs + i] = tail->name;
	g->gl_pathv[offs + i] = NULL;
	g->gl_pathc += cnt;

	if (!(flags & GLOB_NOSORT))
		qsort(g->gl_pathv+offs, cnt, sizeof(char *), sort);
	
	return error;
}

void globfree(glob_t *g)
{
	size_t i;
	for (i=0; i<g->gl_pathc; i++)
		free(g->gl_pathv[g->gl_offs + i] - offsetof(struct match, name));
	free(g->gl_pathv);
	g->gl_pathc = 0;
	g->gl_pathv = NULL;
}