Fix a bug in hex_to_ascii().

6 years ago · b53590fe3a
parent 7aff64740e
commit b53590fe3a
2 changed files with 4 additions and 12 deletions
--- a/22-malloc/libc/string.c
+++ b/22-malloc/libc/string.c
@ -25,17 +25,13 @@ void hex_to_ascii(int n, char str[]) {

    s32 tmp;
    int i;
-    for (i = 28; i > 0; i -= 4) {
+    for (i = 28; i >= 0; i -= 4) {
        tmp = (n >> i) & 0xF;
        if (tmp == 0 && zeros == 0) continue;
        zeros = 1;
-        if (tmp > 0xA) append(str, tmp - 0xA + 'a');
+        if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
        else append(str, tmp + '0');
    }
-
-    tmp = n & 0xF;
-    if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
-    else append(str, tmp + '0');
 }

 /* K&R */
--- a/23-fixes/libc/string.c
+++ b/23-fixes/libc/string.c
@ -25,17 +25,13 @@ void hex_to_ascii(int n, char str[]) {

    int32_t tmp;
    int i;
-    for (i = 28; i > 0; i -= 4) {
+    for (i = 28; i >= 0; i -= 4) {
        tmp = (n >> i) & 0xF;
        if (tmp == 0 && zeros == 0) continue;
        zeros = 1;
-        if (tmp > 0xA) append(str, tmp - 0xA + 'a');
+        if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
        else append(str, tmp + '0');
    }
-
-    tmp = n & 0xF;
-    if (tmp >= 0xA) append(str, tmp - 0xA + 'a');
-    else append(str, tmp + '0');
 }

 /* K&R */