1 files changed, 82 insertions, 0 deletions
diff --git a/src/byte.c b/src/byte.c
new file mode 100644
index 0000000..c6ac6b0
--- /dev/null
+++ b/src/byte.c
@@ -0,0 +1,82 @@
+#include "byte.h"
+
+/**
+  * @file byte.c
+  * @author djb
+  * @brief byte manipulation functions
+  */
+
+unsigned int byte_chr(char *s,unsigned int n,int c)
+{
+  char ch = c;
+  char *t = s;
+
+  for (;;) {
+    if (!n) { break; } if (*t == ch) { break; } ++t; --n;
+  }
+  return t - s;
+}
+
+void byte_copy(void *to,unsigned int n,const void *from)
+{
+  char *out = to;         // share same address
+  const char *in = from;  // one byte 
+
+  for (;;) {
+    if (!n) { return; } *out++ = *in++; --n;
+  }
+}
+
+void byte_copyr(void *to,unsigned int n,const void *from)
+{
+  char *out = to + n;
+  const char *in = from + n;
+
+  for (;;) {
+    if (!n) { return; } *--out = *--in; --n;
+  }
+}
+
+int byte_diff(const void *s,unsigned int n,const void *t)
+{
+  const char *a = s;
+  const char *b = t;
+
+  for (;;) { 
+    if (!n) { return 0; } if (*a != *b) { break; } ++a; ++b; --n;
+  } 
+  return ((int)(unsigned int)(unsigned char) *a)
+       - ((int)(unsigned int)(unsigned char) *b);
+}
+
+unsigned int byte_rchr(char *s,unsigned int n,int c)
+{
+  char ch = c;
+  char *t = s;
+  char *u = 0;
+
+  for (;;) {
+    if (!n) { break; } if (*t == ch) { u = t; } ++t; --n; 
+  }
+  if (!u) { u = t; }
+  return u - s;
+}
+
+void byte_zero(void *s,unsigned int n)
+{
+  char *out  = s;
+
+  for (;;) {
+    if (!n) { break; } *out++ = 0; --n;
+  }
+}
+
+void byte_fill(void *to,unsigned int n,int c)
+{
+  char *s = to;
+  char ch = c;
+
+  for (;;) {
+    if (!n) { break; } *s++ = ch; --n;
+  }
+}