From f529a550a4de36fcbbf3cd4c2d189be8a4535154 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Thu, 28 Mar 2013 22:29:50 -0500
Subject: More uudecode cleanup.

---
 toys/pending/uudecode.c | 89 ++++++++++++++++++++-----------------------------
 1 file changed, 37 insertions(+), 52 deletions(-)

diff --git a/toys/pending/uudecode.c b/toys/pending/uudecode.c
index abd8414f..576b8faf 100644
--- a/toys/pending/uudecode.c
+++ b/toys/pending/uudecode.c
@@ -24,66 +24,44 @@ GLOBALS(
   char *o;
 )
 
-/*
- * Turn a character back into a value.
- * The smallest valid character is 0x2B ('+')
- * The biggest valid character is 0x7A ('z')
- * We can make a table of 16*5 entries to cover 0x2B - 0x7A
- */
-
 static inline signed char uudecode_b64_1byte(char in)
 {
-  char ret;
-  static const signed char table[16*5] = {
-    /* '+' (0x2B) is 62, '/'(0x2F) is 63, rest invalid */
-                                                62, -1, -1, -1, 63,
-    /* '0'-'9' are values 52-61, rest of 0x3A - 0x3F is invalid, = is special... */
-    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-    /* '@' is invalid, 'A'-'Z' are values 0-25, 0x5b - 0x5F are invalid */
-    -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
-    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-    /* '`' is invalid, 'a'-'z' are values 26-51, 0x7B - 0x7F are invalid */
-    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
-    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
-  };
-
-  in &= 0x7f;
-  if (in < '+') return -1;
-  if (in > 'z') return -1;
-  in -= '+';
-  ret = table[in];
+  if (in >= 'A' && in <= 'Z') return in-'A';
+  if (in >= 'a' && in <= 'z') return in-'a'+26;
+  if (in >= '0' && in <= '9') return in-'0'+52;
+  if (in == '+') return 62;
+  if (in == '/') return 63;
 
-  return ret;
+  return -1;
 };
 
 
-/* Returns length put in out */
-static int uudecode_b64_4bytes(char *out, const char *in)
+static int uudecode_b64_4bytes(char *out, char *in)
 {
-  unsigned int i, x=0;
-  signed char b0, b1, b2, b3;
-  int len = 3;
-
-  b0 = uudecode_b64_1byte(in[0]);
-  b1 = uudecode_b64_1byte(in[1]);
-  b2 = uudecode_b64_1byte(in[2]);
-  b3 = uudecode_b64_1byte(in[3]);
-  if ((b1 < 0) || (b0 < 0)) return 0;
-  if (b3 < 0) len--;
-  if (b2 < 0) len--;
-  x = ((b0 & 0x3f)<<18) | ((b1 & 0x3f)<<12) | ((b2 & 0x3f) << 6) | (b3 & 0x3f);
-  for (i = 0; i < len; i++) *out++ = (x>>(8*(2-i))) & 0x0ff;
+  int i, len = 3;
+  unsigned x = 0;
+
+  for (i=0; i<4; i++) {
+    int c = in[i];
+
+    if (c == '=') len--;
+    else if (len != 3) len = 0;
+    if (!len) error_exit("bad input");
+
+    x |= uudecode_b64_1byte(c) << (6*(3-i));
+    if (i && i <= len) *(out++) = (x>>(8*(3-i))) & 0xff;
+  }
 
   return len;
 }
 
-static void uudecode_b64_line(int ofd, const char *in, int ilen)
+static void uudecode_b64_line(int ofd, char *in, int ilen)
 {
   int olen;
   char out[4];
 
   while (ilen >= 4) {
-    olen = uudecode_b64_4bytes(out,in);
+    olen = uudecode_b64_4bytes(out, in);
     xwrite(ofd,out,olen);
     in += 4;
     ilen -= 4;
@@ -104,7 +82,7 @@ static void uudecode_b64(int ifd, int ofd)
 }
 
 
-static void uudecode_uu_4bytes(char *out, const char *in, int len)
+static void uudecode_uu_4bytes(char *out, char *in, int len)
 {
   unsigned int i,x=0;
 
@@ -113,7 +91,7 @@ static void uudecode_uu_4bytes(char *out, const char *in, int len)
   for (i = 0; i < len; i++) *out++ = x >> (8*(2-i));
 }
 
-static void uudecode_uu_line(int ofd, const char *in)
+static void uudecode_uu_line(int ofd, char *in)
 {
   int olen = in[0] - 32;
   char buf[4];
@@ -131,11 +109,15 @@ static void uudecode_uu(int ifd, int ofd)
 {
   char *line = NULL;
 
-  while ((line = get_line(ifd)) != NULL) {
-    if (line[0] == '`') break;
-    if (!strncmp(line, "end", 3)) break;
-    if (strlen(line) < 1) break;
-    uudecode_uu_line(ofd,line);
+  for (;;) {
+    if (!(line = get_line(ifd))) break;
+    if (*line) {
+      if (!strncmp(line, "end", 3)) {
+        free(line);
+        break;
+      }
+      uudecode_uu_line(ofd,line);
+    }
     free(line);
   }
 }
@@ -159,7 +141,10 @@ void uudecode_main(void)
       if (idx) decoder = uudecode_b64;
     }
 
-    if (!idx) continue;
+    if (!idx) {
+      free(line);
+      continue;
+    }
 
     ofd = xcreate(TT.o ? TT.o : line+idx, O_WRONLY|O_CREAT|O_TRUNC,
       string_to_mode(mode, 0777^toys.old_umask));
-- 
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