4 files changed, 47 insertions, 0 deletions
diff --git a/embed.fnc b/embed.fnc
index 44d8d40adf..46fdf46764 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -3053,6 +3053,10 @@ Apnod	|Size_t	|my_strlcat	|NULLOK char *dst|NULLOK const char *src|Size_t size
 Apnod	|Size_t |my_strlcpy     |NULLOK char *dst|NULLOK const char *src|Size_t size
 #endif
 
+#ifndef HAS_MKSTEMP
+pno	|int	|my_mkstemp	|NN char *templte
+#endif
+
 APpdn	|bool	|isinfnan	|NV nv
 p	|bool	|isinfnansv	|NN SV *sv
 
diff --git a/proto.h b/proto.h
index 637b3c913b..6bb89e54ee 100644
--- a/proto.h
+++ b/proto.h
@@ -3856,6 +3856,11 @@ STATIC int	S_dooneliner(pTHX_ const char *cmd, const char *filename)
 
 #  endif
 #endif
+#if !defined(HAS_MKSTEMP)
+PERL_CALLCONV int	Perl_my_mkstemp(char *templte);
+#define PERL_ARGS_ASSERT_MY_MKSTEMP	\
+	assert(templte)
+#endif
 #if !defined(HAS_RENAME)
 PERL_CALLCONV I32	Perl_same_dirent(pTHX_ const char* a, const char* b);
 #define PERL_ARGS_ASSERT_SAME_DIRENT	\
diff --git a/util.c b/util.c
index 136e4ca1ec..e2feb7f473 100644
--- a/util.c
+++ b/util.c
@@ -5789,6 +5789,40 @@ Perl_my_dirfd(DIR * dir) {
 #endif 
 }
 
+#ifndef HAS_MKSTEMP
+
+#define TEMP_FILE_CH "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz0123456789"
+#define TEMP_FILE_CH_COUNT (sizeof(TEMP_FILE_CH)-1)
+
+int
+Perl_my_mkstemp(char *templte) {
+    dTHX;
+    STRLEN len = strlen(templte);
+    int fd;
+    int attempts = 0;
+
+    PERL_ARGS_ASSERT_MY_MKSTEMP;
+
+    if (len < 6 ||
+        templte[len-1] != 'X' || templte[len-2] != 'X' || templte[len-3] != 'X' ||
+        templte[len-4] != 'X' || templte[len-5] != 'X' || templte[len-6] != 'X') {
+        errno = EINVAL;
+        return -1;
+    }
+
+    do {
+        int i;
+        for (i = 1; i <= 6; ++i) {
+            templte[len-i] = TEMP_FILE_CH[(int)(Perl_internal_drand48() * TEMP_FILE_CH_COUNT)];
+        }
+        fd = PerlLIO_open3(templte, O_RDWR | O_CREAT | O_EXCL, 0600);
+    } while (fd == -1 && errno == EEXIST && ++attempts <= 100);
+
+    return fd;
+}
+
+#endif
+
 REGEXP *
 Perl_get_re_arg(pTHX_ SV *sv) {
 
diff --git a/util.h b/util.h
index 4589808ee1..6b63d90e4f 100644
--- a/util.h
+++ b/util.h
@@ -246,6 +246,10 @@ means arg not present, 1 is empty string/null byte */
             ((char *) memmem(big, bigend - big, little, lend - little))
 #endif
 
+#if defined(HAS_MKSTEMP) && defined(PERL_CORE)
+#   define Perl_my_mkstemp(templte) mkstemp(templte)
+#endif
+
 #endif /* PERL_UTIL_H_ */
 
 /*