[Qemu-devel] [PATCH 1/2] qemu_hexstr(): hexdump a small buffer to a string, for in-line printing

[Laszlo Ersek <lersek@redhat.com>]

This function should primarily serve tracing needs.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 include/qemu-common.h |   11 +++++++++++
 util/hexdump.c        |   20 ++++++++++++++++++++
 2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/qemu-common.h b/include/qemu-common.h
index 6948bb9..18a373f 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -433,6 +433,17 @@ int mod_utf8_codepoint(const char *s, size_t n, char **end);
 
 void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size);
 
+/*
+ * Hexdump @size bytes from @buf to a dynamically allocated string.
+ * If @size is NULL, then @buf can be a NULL pointer, and an empty string will
+ * be formatted.
+ * If @str_len is non-NULL, then the length of the output string (excluding the
+ * terminating NUL) will be stored in *@str_len.
+ * The output is meant to be printed on a single line, hence it contains no
+ * newlines, and @size should be reasonable.
+ */
+char *qemu_hexstr(const void *buf, size_t size, size_t *str_len);
+
 /* vector definitions */
 #ifdef __ALTIVEC__
 #include <altivec.h>
diff --git a/util/hexdump.c b/util/hexdump.c
index 969b340..5c7e1a2 100644
--- a/util/hexdump.c
+++ b/util/hexdump.c
@@ -35,3 +35,23 @@ void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size)
         fprintf(fp, "\n");
     }
 }
+
+char *qemu_hexstr(const void *buf, size_t size, size_t *str_len)
+{
+    size_t str_size, i;
+    char *ret, *output;
+
+    str_size = size * 3 + (size == 0);
+    ret = g_malloc(str_size);
+    output = ret;
+
+    for (i = 0; i < size; ++i) {
+        output += sprintf(output, "%s%02x", (i == 0) ? "" : " ",
+                          ((uint8_t *)buf)[i]);
+    }
+    *output = '\0';
+    if (str_len != NULL) {
+        *str_len = str_size - 1;
+    }
+    return ret;
+}
-- 
1.7.1