str_utils: add hexdump()

peter-pycom · peter-pycom · commit 7d2e8e053c8d · 2020-11-23T18:18:44.000+01:00
diff --git a/esp32/util/str_utils.c b/esp32/util/str_utils.c
@@ -1,5 +1,6 @@
 #include "str_utils.h"
 #include <stdio.h>
+#include <string.h>
 
 /**
  * Create a string representation of a uint8
@@ -18,3 +19,43 @@ void sprint_binary_u8(char* s, uint8_t v){
            );
 }
 
+/* hexdump a buffer
+*/
+void hexdump(const uint8_t* buf, size_t len){
+    const size_t line_len = 16;
+    uint8_t line[line_len+1];
+    memset(line, ' ', line_len);
+    line[line_len] = '\0';
+
+    for ( size_t i = 0; i < len; ++i) {
+        uint8_t c = buf[i];
+        printf("%02x ", c);
+        if (   (c >= (uint8_t)'a' &&  c <= (uint8_t)'z')
+            || (c >= (uint8_t)'A' &&  c <= (uint8_t)'Z')
+            || (c >= (uint8_t)'0' &&  c <= (uint8_t)'9') )
+        {
+            line[i%line_len] = c;
+        } else {
+            line[i%line_len] = '.';
+        }
+
+        // space after 8 bytes
+        if (i%16 == 7)
+            printf("  ");
+        // end of line after 16 bytes
+        if (i%16==15){
+            printf("  |%s|\n", line);
+            memset(line, ' ', line_len);
+        }
+    }
+    if ( len % line_len ){
+        // space after 8 bytes
+        if ( len % line_len < 7)
+            printf("  ");
+        // spaces for bytes we didn't have to print
+        for ( size_t j = line_len; j > len % line_len; j-- ){
+            printf("   ");
+        }
+        printf("  |%s|\n", line);
+    }
+}
diff --git a/esp32/util/str_utils.h b/esp32/util/str_utils.h
@@ -14,4 +14,6 @@
 
 void sprint_binary_u8(char* s, uint8_t v);
 
+void hexdump(const uint8_t* buf, size_t len);
+
 #endif
