Adding upstream version 1:5.44.upstream/1%5.44upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 918 insertions, 0 deletions

diff --git a/src/funcs.c b/src/funcs.c
new file mode 100644
index 0000000..d4fefcd
--- /dev/null
+++ b/src/funcs.c
@@ -0,0 +1,918 @@
+/*
+ * Copyright (c) Christos Zoulas 2003.
+ * 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 immediately at the beginning of the file, without modification,
+ *    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 "file.h"
+
+#ifndef	lint
+FILE_RCSID("@(#)$File: funcs.c,v 1.136 2022/12/26 17:31:14 christos Exp $")
+#endif	/* lint */
+
+#include "magic.h"
+#include <assert.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>	/* for pipe2() */
+#endif
+#if defined(HAVE_WCHAR_H)
+#include <wchar.h>
+#endif
+#if defined(HAVE_WCTYPE_H)
+#include <wctype.h>
+#endif
+#include <limits.h>
+
+#ifndef SIZE_MAX
+#define SIZE_MAX	((size_t)~0)
+#endif
+
+file_protected char *
+file_copystr(char *buf, size_t blen, size_t width, const char *str)
+{
+	if (blen == 0)
+		return buf;
+	if (width >= blen)
+		width = blen - 1;
+	memcpy(buf, str, width);
+	buf[width] = '\0';
+	return buf;
+}
+
+file_private void
+file_clearbuf(struct magic_set *ms)
+{
+	free(ms->o.buf);
+	ms->o.buf = NULL;
+	ms->o.blen = 0;
+}
+
+file_private int
+file_checkfield(char *msg, size_t mlen, const char *what, const char **pp)
+{
+	const char *p = *pp;
+	int fw = 0;
+
+	while (*p && isdigit((unsigned char)*p))
+		fw = fw * 10 + (*p++ - '0');
+
+	*pp = p;
+
+	if (fw < 1024)
+		return 1;
+	if (msg)
+		snprintf(msg, mlen, "field %s too large: %d", what, fw);
+
+	return 0;
+}
+
+file_protected int
+file_checkfmt(char *msg, size_t mlen, const char *fmt)
+{
+	const char *p;
+	for (p = fmt; *p; p++) {
+		if (*p != '%')
+			continue;
+		if (*++p == '%')
+			continue;
+		// Skip uninteresting.
+		while (strchr("#0.'+- ", *p) != NULL)
+			p++;
+		if (*p == '*') {
+			if (msg)
+				snprintf(msg, mlen, "* not allowed in format");
+			return -1;
+		}
+
+		if (!file_checkfield(msg, mlen, "width", &p))
+			return -1;
+
+		if (*p == '.') {
+			p++;
+			if (!file_checkfield(msg, mlen, "precision", &p))
+				return -1;
+		}
+
+		if (!isalpha((unsigned char)*p)) {
+			if (msg)
+				snprintf(msg, mlen, "bad format char: %c", *p);
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Like printf, only we append to a buffer.
+ */
+file_protected int
+file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
+{
+	int len;
+	char *buf, *newstr;
+	char tbuf[1024];
+
+	if (ms->event_flags & EVENT_HAD_ERR)
+		return 0;
+
+	if (file_checkfmt(tbuf, sizeof(tbuf), fmt)) {
+		file_clearbuf(ms);
+		file_error(ms, 0, "Bad magic format `%s' (%s)", fmt, tbuf);
+		return -1;
+	}
+
+	len = vasprintf(&buf, fmt, ap);
+	if (len < 0 || (size_t)len > 1024 || len + ms->o.blen > 1024 * 1024) {
+		size_t blen = ms->o.blen;
+		free(buf);
+		file_clearbuf(ms);
+		file_error(ms, 0, "Output buffer space exceeded %d+%"
+		    SIZE_T_FORMAT "u", len, blen);
+		return -1;
+	}
+
+	if (ms->o.buf != NULL) {
+		len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
+		free(buf);
+		if (len < 0)
+			goto out;
+		free(ms->o.buf);
+		buf = newstr;
+	}
+	ms->o.buf = buf;
+	ms->o.blen = len;
+	return 0;
+out:
+	file_clearbuf(ms);
+	file_error(ms, errno, "vasprintf failed");
+	return -1;
+}
+
+file_protected int
+file_printf(struct magic_set *ms, const char *fmt, ...)
+{
+	int rv;
+	va_list ap;
+
+	va_start(ap, fmt);
+	rv = file_vprintf(ms, fmt, ap);
+	va_end(ap);
+	return rv;
+}
+
+/*
+ * error - print best error message possible
+ */
+/*VARARGS*/
+__attribute__((__format__(__printf__, 3, 0)))
+file_private void
+file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
+    size_t lineno)
+{
+	/* Only the first error is ok */
+	if (ms->event_flags & EVENT_HAD_ERR)
+		return;
+	if (lineno != 0) {
+		file_clearbuf(ms);
+		(void)file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno);
+	}
+	if (ms->o.buf && *ms->o.buf)
+		(void)file_printf(ms, " ");
+	(void)file_vprintf(ms, f, va);
+	if (error > 0)
+		(void)file_printf(ms, " (%s)", strerror(error));
+	ms->event_flags |= EVENT_HAD_ERR;
+	ms->error = error;
+}
+
+/*VARARGS*/
+file_protected void
+file_error(struct magic_set *ms, int error, const char *f, ...)
+{
+	va_list va;
+	va_start(va, f);
+	file_error_core(ms, error, f, va, 0);
+	va_end(va);
+}
+
+/*
+ * Print an error with magic line number.
+ */
+/*VARARGS*/
+file_protected void
+file_magerror(struct magic_set *ms, const char *f, ...)
+{
+	va_list va;
+	va_start(va, f);
+	file_error_core(ms, 0, f, va, ms->line);
+	va_end(va);
+}
+
+file_protected void
+file_oomem(struct magic_set *ms, size_t len)
+{
+	file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
+	    len);
+}
+
+file_protected void
+file_badseek(struct magic_set *ms)
+{
+	file_error(ms, errno, "error seeking");
+}
+
+file_protected void
+file_badread(struct magic_set *ms)
+{
+	file_error(ms, errno, "error reading");
+}
+
+#ifndef COMPILE_ONLY
+#define FILE_SEPARATOR "\n- "
+
+file_protected int
+file_separator(struct magic_set *ms)
+{
+	return file_printf(ms, FILE_SEPARATOR);
+}
+
+static void
+trim_separator(struct magic_set *ms)
+{
+	size_t l;
+
+	if (ms->o.buf == NULL)
+		return;
+
+	l = strlen(ms->o.buf);
+	if (l < sizeof(FILE_SEPARATOR))
+		return;
+
+	l -= sizeof(FILE_SEPARATOR) - 1;
+	if (strcmp(ms->o.buf + l, FILE_SEPARATOR) != 0)
+		return;
+
+	ms->o.buf[l] = '\0';
+}
+
+static int
+checkdone(struct magic_set *ms, int *rv)
+{
+	if ((ms->flags & MAGIC_CONTINUE) == 0)
+		return 1;
+	if (file_separator(ms) == -1)
+		*rv = -1;
+	return 0;
+}
+
+file_protected int
+file_default(struct magic_set *ms, size_t nb)
+{
+	if (ms->flags & MAGIC_MIME) {
+		if ((ms->flags & MAGIC_MIME_TYPE) &&
+		    file_printf(ms, "application/%s",
+			nb ? "octet-stream" : "x-empty") == -1)
+			return -1;
+		return 1;
+	}
+	if (ms->flags & MAGIC_APPLE) {
+		if (file_printf(ms, "UNKNUNKN") == -1)
+			return -1;
+		return 1;
+	}
+	if (ms->flags & MAGIC_EXTENSION) {
+		if (file_printf(ms, "???") == -1)
+			return -1;
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * The magic detection functions return:
+ *	 1: found
+ *	 0: not found
+ *	-1: error
+ */
+/*ARGSUSED*/
+file_protected int
+file_buffer(struct magic_set *ms, int fd, struct stat *st,
+    const char *inname __attribute__ ((__unused__)),
+    const void *buf, size_t nb)
+{
+	int m = 0, rv = 0, looks_text = 0;
+	const char *code = NULL;
+	const char *code_mime = "binary";
+	const char *def = "data";
+	const char *ftype = NULL;
+	char *rbuf = NULL;
+	struct buffer b;
+
+	buffer_init(&b, fd, st, buf, nb);
+	ms->mode = b.st.st_mode;
+
+	if (nb == 0) {
+		def = "empty";
+		goto simple;
+	} else if (nb == 1) {
+		def = "very short file (no magic)";
+		goto simple;
+	}
+
+	if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
+		looks_text = file_encoding(ms, &b, NULL, 0,
+		    &code, &code_mime, &ftype);
+	}
+
+#ifdef __EMX__
+	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
+		m = file_os2_apptype(ms, inname, &b);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try os2_apptype %d]\n", m);
+		switch (m) {
+		case -1:
+			return -1;
+		case 0:
+			break;
+		default:
+			return 1;
+		}
+	}
+#endif
+#if HAVE_FORK
+	/* try compression stuff */
+	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
+		m = file_zmagic(ms, &b, inname);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try zmagic %d]\n", m);
+		if (m) {
+			goto done_encoding;
+		}
+	}
+#endif
+	/* Check if we have a tar file */
+	if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
+		m = file_is_tar(ms, &b);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try tar %d]\n", m);
+		if (m) {
+			if (checkdone(ms, &rv))
+				goto done;
+		}
+	}
+
+	/* Check if we have a JSON file */
+	if ((ms->flags & MAGIC_NO_CHECK_JSON) == 0) {
+		m = file_is_json(ms, &b);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try json %d]\n", m);
+		if (m) {
+			if (checkdone(ms, &rv))
+				goto done;
+		}
+	}
+
+	/* Check if we have a CSV file */
+	if ((ms->flags & MAGIC_NO_CHECK_CSV) == 0) {
+		m = file_is_csv(ms, &b, looks_text);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try csv %d]\n", m);
+		if (m) {
+			if (checkdone(ms, &rv))
+				goto done;
+		}
+	}
+
+	/* Check if we have a CDF file */
+	if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
+		m = file_trycdf(ms, &b);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try cdf %d]\n", m);
+		if (m) {
+			if (checkdone(ms, &rv))
+				goto done;
+		}
+	}
+#ifdef BUILTIN_ELF
+	if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && nb > 5 && fd != -1) {
+		file_pushbuf_t *pb;
+		/*
+		 * We matched something in the file, so this
+		 * *might* be an ELF file, and the file is at
+		 * least 5 bytes long, so if it's an ELF file
+		 * it has at least one byte past the ELF magic
+		 * number - try extracting information from the
+		 * ELF headers that cannot easily be  extracted
+		 * with rules in the magic file. We we don't
+		 * print the information yet.
+		 */
+		if ((pb = file_push_buffer(ms)) == NULL)
+			return -1;
+
+		rv = file_tryelf(ms, &b);
+		rbuf = file_pop_buffer(ms, pb);
+		if (rv == -1) {
+			free(rbuf);
+			rbuf = NULL;
+		}
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try elf %d]\n", m);
+	}
+#endif
+
+	/* try soft magic tests */
+	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
+		m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try softmagic %d]\n", m);
+		if (m == 1 && rbuf) {
+			if (file_printf(ms, "%s", rbuf) == -1)
+				goto done;
+		}
+		if (m) {
+			if (checkdone(ms, &rv))
+				goto done;
+		}
+	}
+
+	/* try text properties */
+	if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
+
+		m = file_ascmagic(ms, &b, looks_text);
+		if ((ms->flags & MAGIC_DEBUG) != 0)
+			(void)fprintf(stderr, "[try ascmagic %d]\n", m);
+		if (m) {
+			goto done;
+		}
+	}
+
+simple:
+	/* give up */
+	if (m == 0) {
+		m = 1;
+		rv = file_default(ms, nb);
+		if (rv == 0)
+			if (file_printf(ms, "%s", def) == -1)
+				rv = -1;
+	}
+ done:
+	trim_separator(ms);
+	if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
+		if (ms->flags & MAGIC_MIME_TYPE)
+			if (file_printf(ms, "; charset=") == -1)
+				rv = -1;
+		if (file_printf(ms, "%s", code_mime) == -1)
+			rv = -1;
+	}
+#if HAVE_FORK
+ done_encoding:
+#endif
+	free(rbuf);
+	buffer_fini(&b);
+	if (rv)
+		return rv;
+
+	return m;
+}
+#endif
+
+file_protected int
+file_reset(struct magic_set *ms, int checkloaded)
+{
+	if (checkloaded && ms->mlist[0] == NULL) {
+		file_error(ms, 0, "no magic files loaded");
+		return -1;
+	}
+	file_clearbuf(ms);
+	if (ms->o.pbuf) {
+		free(ms->o.pbuf);
+		ms->o.pbuf = NULL;
+	}
+	ms->event_flags &= ~EVENT_HAD_ERR;
+	ms->error = -1;
+	return 0;
+}
+
+#define OCTALIFY(n, o)	\
+	/*LINTED*/ \
+	(void)(*(n)++ = '\\', \
+	*(n)++ = ((CAST(uint32_t, *(o)) >> 6) & 3) + '0', \
+	*(n)++ = ((CAST(uint32_t, *(o)) >> 3) & 7) + '0', \
+	*(n)++ = ((CAST(uint32_t, *(o)) >> 0) & 7) + '0', \
+	(o)++)
+
+file_protected const char *
+file_getbuffer(struct magic_set *ms)
+{
+	char *pbuf, *op, *np;
+	size_t psize, len;
+
+	if (ms->event_flags & EVENT_HAD_ERR)
+		return NULL;
+
+	if (ms->flags & MAGIC_RAW)
+		return ms->o.buf;
+
+	if (ms->o.buf == NULL)
+		return NULL;
+
+	/* * 4 is for octal representation, + 1 is for NUL */
+	len = strlen(ms->o.buf);
+	if (len > (SIZE_MAX - 1) / 4) {
+		file_oomem(ms, len);
+		return NULL;
+	}
+	psize = len * 4 + 1;
+	if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
+		file_oomem(ms, psize);
+		return NULL;
+	}
+	ms->o.pbuf = pbuf;
+
+#if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
+	{
+		mbstate_t state;
+		wchar_t nextchar;
+		int mb_conv = 1;
+		size_t bytesconsumed;
+		char *eop;
+		(void)memset(&state, 0, sizeof(mbstate_t));
+
+		np = ms->o.pbuf;
+		op = ms->o.buf;
+		eop = op + len;
+
+		while (op < eop) {
+			bytesconsumed = mbrtowc(&nextchar, op,
+			    CAST(size_t, eop - op), &state);
+			if (bytesconsumed == CAST(size_t, -1) ||
+			    bytesconsumed == CAST(size_t, -2)) {
+				mb_conv = 0;
+				break;
+			}
+
+			if (iswprint(nextchar)) {
+				(void)memcpy(np, op, bytesconsumed);
+				op += bytesconsumed;
+				np += bytesconsumed;
+			} else {
+				while (bytesconsumed-- > 0)
+					OCTALIFY(np, op);
+			}
+		}
+		*np = '\0';
+
+		/* Parsing succeeded as a multi-byte sequence */
+		if (mb_conv != 0)
+			return ms->o.pbuf;
+	}
+#endif
+
+	for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
+		if (isprint(CAST(unsigned char, *op))) {
+			*np++ = *op++;
+		} else {
+			OCTALIFY(np, op);
+		}
+	}
+	*np = '\0';
+	return ms->o.pbuf;
+}
+
+file_protected int
+file_check_mem(struct magic_set *ms, unsigned int level)
+{
+	size_t len;
+
+	if (level >= ms->c.len) {
+		len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
+		ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
+		    malloc(len) :
+		    realloc(ms->c.li, len));
+		if (ms->c.li == NULL) {
+			file_oomem(ms, len);
+			return -1;
+		}
+	}
+	ms->c.li[level].got_match = 0;
+#ifdef ENABLE_CONDITIONALS
+	ms->c.li[level].last_match = 0;
+	ms->c.li[level].last_cond = COND_NONE;
+#endif /* ENABLE_CONDITIONALS */
+	return 0;
+}
+
+file_protected size_t
+file_printedlen(const struct magic_set *ms)
+{
+	return ms->o.blen;
+}
+
+file_protected int
+file_replace(struct magic_set *ms, const char *pat, const char *rep)
+{
+	file_regex_t rx;
+	int rc, rv = -1;
+
+	rc = file_regcomp(ms, &rx, pat, REG_EXTENDED);
+	if (rc == 0) {
+		regmatch_t rm;
+		int nm = 0;
+		while (file_regexec(ms, &rx, ms->o.buf, 1, &rm, 0) == 0) {
+			ms->o.buf[rm.rm_so] = '\0';
+			if (file_printf(ms, "%s%s", rep,
+			    rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
+				goto out;
+			nm++;
+		}
+		rv = nm;
+	}
+out:
+	file_regfree(&rx);
+	return rv;
+}
+
+file_private int
+check_regex(struct magic_set *ms, const char *pat)
+{
+	char sbuf[512];
+	unsigned char oc = '\0';
+
+	for (const char *p = pat; *p; p++) {
+		unsigned char c = *p;
+		// Avoid repetition
+		if (c == oc && strchr("?*+{", c) != NULL) {
+			size_t len = strlen(pat);
+			file_magwarn(ms,
+			    "repetition-operator operand `%c' "
+			    "invalid in regex `%s'", c,
+			    file_printable(ms, sbuf, sizeof(sbuf), pat, len));
+			return -1;
+		}
+		oc = c;
+		if (isprint(c) || isspace(c) || c == '\b'
+		    || c == 0x8a) // XXX: apple magic fixme
+			continue;
+		size_t len = strlen(pat);
+		file_magwarn(ms,
+		    "non-ascii characters in regex \\%#o `%s'",
+		    c, file_printable(ms, sbuf, sizeof(sbuf), pat, len));
+		return -1;
+	}
+	return 0;
+}
+
+file_protected int
+file_regcomp(struct magic_set *ms file_locale_used, file_regex_t *rx,
+    const char *pat, int flags)
+{
+	if (check_regex(ms, pat) == -1)
+		return -1;
+
+#ifdef USE_C_LOCALE
+	locale_t old = uselocale(ms->c_lc_ctype);
+	assert(old != NULL);
+#else
+	char old[1024];
+	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
+	(void)setlocale(LC_CTYPE, "C");
+#endif
+	int rc;
+	rc = regcomp(rx, pat, flags);
+
+#ifdef USE_C_LOCALE
+	uselocale(old);
+#else
+	(void)setlocale(LC_CTYPE, old);
+#endif
+	if (rc > 0 && (ms->flags & MAGIC_CHECK)) {
+		char errmsg[512], buf[512];
+
+		(void)regerror(rc, rx, errmsg, sizeof(errmsg));
+		file_magerror(ms, "regex error %d for `%s', (%s)", rc, 
+		    file_printable(ms, buf, sizeof(buf), pat, strlen(pat)),
+		    errmsg);
+	}
+	return rc;
+}
+
+/*ARGSUSED*/
+file_protected int
+file_regexec(struct magic_set *ms file_locale_used, file_regex_t *rx,
+    const char *str, size_t nmatch, regmatch_t* pmatch, int eflags)
+{
+#ifdef USE_C_LOCALE
+	locale_t old = uselocale(ms->c_lc_ctype);
+	assert(old != NULL);
+#else
+	char old[1024];
+	strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
+	(void)setlocale(LC_CTYPE, "C");
+#endif
+	int rc;
+	/* XXX: force initialization because glibc does not always do this */
+	if (nmatch != 0)
+		memset(pmatch, 0, nmatch * sizeof(*pmatch));
+	rc = regexec(rx, str, nmatch, pmatch, eflags);
+#ifdef USE_C_LOCALE
+	uselocale(old);
+#else
+	(void)setlocale(LC_CTYPE, old);
+#endif
+	return rc;
+}
+
+file_protected void
+file_regfree(file_regex_t *rx)
+{
+	regfree(rx);
+}
+
+file_protected file_pushbuf_t *
+file_push_buffer(struct magic_set *ms)
+{
+	file_pushbuf_t *pb;
+
+	if (ms->event_flags & EVENT_HAD_ERR)
+		return NULL;
+
+	if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
+		return NULL;
+
+	pb->buf = ms->o.buf;
+	pb->blen = ms->o.blen;
+	pb->offset = ms->offset;
+
+	ms->o.buf = NULL;
+	ms->o.blen = 0;
+	ms->offset = 0;
+
+	return pb;
+}
+
+file_protected char *
+file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
+{
+	char *rbuf;
+
+	if (ms->event_flags & EVENT_HAD_ERR) {
+		free(pb->buf);
+		free(pb);
+		return NULL;
+	}
+
+	rbuf = ms->o.buf;
+
+	ms->o.buf = pb->buf;
+	ms->o.blen = pb->blen;
+	ms->offset = pb->offset;
+
+	free(pb);
+	return rbuf;
+}
+
+/*
+ * convert string to ascii printable format.
+ */
+file_protected char *
+file_printable(struct magic_set *ms, char *buf, size_t bufsiz,
+    const char *str, size_t slen)
+{
+	char *ptr, *eptr = buf + bufsiz - 1;
+	const unsigned char *s = RCAST(const unsigned char *, str);
+	const unsigned char *es = s + slen;
+
+	for (ptr = buf;  ptr < eptr && s < es && *s; s++) {
+		if ((ms->flags & MAGIC_RAW) != 0 || isprint(*s)) {
+			*ptr++ = *s;
+			continue;
+		}
+		if (ptr >= eptr - 3)
+			break;
+		*ptr++ = '\\';
+		*ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
+		*ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
+		*ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
+	}
+	*ptr = '\0';
+	return buf;
+}
+
+struct guid {
+	uint32_t data1;
+	uint16_t data2;
+	uint16_t data3;
+	uint8_t data4[8];
+};
+
+file_protected int
+file_parse_guid(const char *s, uint64_t *guid)
+{
+	struct guid *g = CAST(struct guid *, CAST(void *, guid));
+#ifndef WIN32
+	return sscanf(s,
+	    "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
+	    &g->data1, &g->data2, &g->data3, &g->data4[0], &g->data4[1],
+	    &g->data4[2], &g->data4[3], &g->data4[4], &g->data4[5],
+	    &g->data4[6], &g->data4[7]) == 11 ? 0 : -1;
+#else
+	/* MS-Windows runtime doesn't support %hhx, except under
+	   non-default __USE_MINGW_ANSI_STDIO.  */
+	uint16_t data16[8];
+	int rv = sscanf(s, "%8x-%4hx-%4hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx",
+	    &g->data1, &g->data2, &g->data3, &data16[0], &data16[1],
+	    &data16[2], &data16[3], &data16[4], &data16[5],
+	    &data16[6], &data16[7]) == 11 ? 0 : -1;
+	int i;
+	for (i = 0; i < 8; i++)
+	    g->data4[i] = data16[i];
+	return rv;
+#endif
+}
+
+file_protected int
+file_print_guid(char *str, size_t len, const uint64_t *guid)
+{
+	const struct guid *g = CAST(const struct guid *,
+	    CAST(const void *, guid));
+
+#ifndef WIN32
+	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hhX%.2hhX-"
+	    "%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX",
+	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
+	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
+	    g->data4[6], g->data4[7]);
+#else
+	return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hX%.2hX-"
+	    "%.2hX%.2hX%.2hX%.2hX%.2hX%.2hX",
+	    g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
+	    g->data4[2], g->data4[3], g->data4[4], g->data4[5],
+	    g->data4[6], g->data4[7]);
+#endif
+}
+
+file_protected int
+file_pipe_closexec(int *fds)
+{
+#ifdef HAVE_PIPE2
+	return pipe2(fds, O_CLOEXEC);
+#else
+	if (pipe(fds) == -1)
+		return -1;
+# ifdef F_SETFD
+	(void)fcntl(fds[0], F_SETFD, FD_CLOEXEC);
+	(void)fcntl(fds[1], F_SETFD, FD_CLOEXEC);
+# endif
+	return 0;
+#endif
+}
+
+file_protected int
+file_clear_closexec(int fd) {
+#ifdef F_SETFD
+	return fcntl(fd, F_SETFD, 0);
+#else
+	return 0;
+#endif
+}
+
+file_protected char *
+file_strtrim(char *str)
+{
+	char *last;
+
+	while (isspace(CAST(unsigned char, *str)))
+		str++;
+	last = str;
+	while (*last)
+		last++;
+	--last;
+	while (isspace(CAST(unsigned char, *last)))
+		last--;
+	*++last = '\0';
+	return str;
+}