Provide a memmem() if the system lacks it.

Reported by:	Frank W. Josellis <frank@dynamical-systems.org>

2 files changed, 44 insertions, 1 deletions

diff --git a/archivers/unmakeself/Makefile b/archivers/unmakeself/Makefile
index 704799081d5e..e7d6b837c2e8 100644
--- a/archivers/unmakeself/Makefile
+++ b/archivers/unmakeself/Makefile
@@ -27,8 +27,16 @@ CPPFLAGS+=	-I${LOCALBASE}/include
 LDFLAGS+=	-L${LOCALBASE}/lib
 .endif
 
+do-configure:
+	@${RM} -f ${WRKSRC}/config.h
+	@if ${GREP} -q memmem /usr/include/string.h; then \
+		${ECHO_CMD} "#define HAS_MEMMEM" > ${WRKSRC}/config.h; \
+	else \
+		${ECHO_CMD} "#undef HAS_MEMMEM" > ${WRKSRC}/config.h; \
+	fi
+
 do-build:
-	${CC} ${CFLAGS} ${CPPFLAGS} -o ${WRKSRC}/unmakeself \
+	${CC} ${CFLAGS} ${CPPFLAGS} -I${WRKSRC} -o ${WRKSRC}/unmakeself \
 		${FILESDIR}/unmakeself.c ${LDFLAGS}
 
 do-install:
diff --git a/archivers/unmakeself/files/unmakeself.c b/archivers/unmakeself/files/unmakeself.c
index d4b9542e110a..bc275d19b6e2 100644
--- a/archivers/unmakeself/files/unmakeself.c
+++ b/archivers/unmakeself/files/unmakeself.c
@@ -42,6 +42,7 @@
 #include <unistd.h>
 #include <getopt.h>
 #include <archive.h>
+#include "config.h"
 
 #define N_ELEMENTS(arr)		(sizeof(arr) / sizeof((arr)[0]))
 
@@ -50,6 +51,40 @@ static char *filename;
 static struct archive *archive;
 static int extract_flags = ARCHIVE_EXTRACT_TIME;	/* bsdtar default */
 
+#ifndef HAS_MEMMEM
+/* taken from lib/libc/string/memmem.c */
+static void *
+memmem(l, l_len, s, s_len)
+	const void *l; size_t l_len;
+	const void *s; size_t s_len;
+{
+	register char *cur, *last;
+	const char *cl = (const char *)l;
+	const char *cs = (const char *)s;
+
+	/* we need something to compare */
+	if (l_len == 0 || s_len == 0)
+		return NULL;
+
+	/* "s" must be smaller or equal to "l" */
+	if (l_len < s_len)
+		return NULL;
+
+	/* special case where s_len == 1 */
+	if (s_len == 1)
+		return memchr(l, (int)*cs, l_len);
+
+	/* the last position where its possible to find "s" in "l" */
+	last = (char *)cl + l_len - s_len;
+
+	for (cur = (char *)cl; cur <= last; cur++)
+		if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
+			return cur;
+
+	return NULL;
+}
+#endif /* HAS_MEMMEM */
+
 static void
 unmakeself_print_help (void)
 {