1 files changed, 97 insertions, 0 deletions
diff --git a/toys/pending/xxd.c b/toys/pending/xxd.c
new file mode 100644
index 00000000..3a84c988
--- /dev/null
+++ b/toys/pending/xxd.c
@@ -0,0 +1,97 @@
+/* xxd.c - hexdump.
+ *
+ * Copyright 2015 The Android Open Source Project
+ *
+ * TODO: support for reversing a hexdump back into the original data.
+ * TODO: support > 4GiB files?
+ * TODO: -s seek
+
+USE_XXD(NEWTOY(xxd, ">1c#l#g#", TOYFLAG_USR|TOYFLAG_BIN))
+
+config XXD
+  bool "xxd"
+  default n
+  help
+    usage: xxd [-c n] [-g n] [-l n] [file]
+
+    Hexdump a file to stdout.  If no file is listed, copy from stdin.
+    Filename "-" is a synonym for stdin.
+
+    -c n	Show n bytes per line (default 16).
+    -g n	Group bytes by adding a ' ' every n bytes (default 2).
+    -l n	Limit of n bytes before stopping (default is no limit).
+*/
+
+#define FOR_xxd
+#include "toys.h"
+
+static const char* hex_digits = "0123456789abcdef";
+
+GLOBALS(
+  long bytes_per_group; // -g
+  long limit; // -l
+  long bytes_per_line; // -c
+)
+
+static void xxd_file(FILE *fp)
+{
+  // "0000000: 4c69 6e75 7820 7665 7273 696f 6e20 332e  Linux version 3.".
+  size_t hex_size = 8 + 2 +
+      2*TT.bytes_per_line + TT.bytes_per_line/TT.bytes_per_group + 1;
+  size_t line_size = hex_size + TT.bytes_per_line + 1;
+  char *line = xmalloc(line_size);
+  int offset = 0;
+  int bytes_this_line = 0;
+  int line_index = 0;
+  int ch;
+
+  memset(line, ' ', line_size);
+  line[line_size - 1] = 0;
+
+  while ((ch = getc(fp)) != EOF) {
+    if (bytes_this_line == 0) line_index = sprintf(line, "%08x: ", offset);
+    ++offset;
+
+    line[line_index++] = hex_digits[(ch >> 4) & 0xf];
+    line[line_index++] = hex_digits[ch & 0xf];
+    line[hex_size + bytes_this_line] = (ch >= ' ' && ch <= '~') ? ch : '.';
+
+    ++bytes_this_line;
+    if (bytes_this_line == TT.bytes_per_line) {
+      puts(line);
+      memset(line, ' ', line_size - 1);
+      bytes_this_line = 0;
+    } else if ((bytes_this_line % TT.bytes_per_group) == 0) {
+      line[line_index++] = ' ';
+    }
+    if ((toys.optflags & FLAG_l) && offset == TT.limit) {
+      break;
+    }
+  }
+  if (bytes_this_line != 0) {
+    line[hex_size + bytes_this_line] = 0;
+    puts(line);
+  }
+
+  if (CFG_FREE) free(line);
+}
+
+void xxd_main(void)
+{
+  FILE *fp;
+
+  if (!TT.bytes_per_line) TT.bytes_per_line = 16;
+  else if (TT.bytes_per_line < 0)
+    error_exit("invalid -c value: %d", TT.bytes_per_line);
+
+  if (!TT.bytes_per_group) TT.bytes_per_group = 2;
+  else if (TT.bytes_per_group < 0)
+    error_exit("invalid -g value: %d", TT.bytes_per_group);
+
+  if (!*toys.optargs || !strcmp(*toys.optargs, "-")) fp = stdin;
+  else fp = xfopen(*toys.optargs, "r");
+
+  xxd_file(fp);
+
+  fclose(fp);
+}