Add base64.

The tizen guys wanted this. Yeah, I know there's base64 code in
uuencode/uudecode, but that this has -i, input lines aren't of fixed length,
encode/decode are in same file, there's no prefix/suffix code, it always
writes to stdout... Eliminating the code duplication wouldn't be worth
the if/else I'd have to add, so I just did a new one.

Factored out the base64 table init into lib.c though: that was worth sharing.

3 files changed, 103 insertions, 10 deletions

diff --git a/lib/lib.c b/lib/lib.c
index 33be44b6..490235f4 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -571,6 +571,21 @@ void crc_init(unsigned int *crc_table, int little_endian)
   }
 }
 
+// Init base64 table
+
+void base64_init(char *p)
+{
+  int i;
+
+  for (i = 'A'; i != ':'; i++) {
+    if (i == 'Z'+1) i = 'a';
+    if (i == 'z'+1) i = '0';
+    *(p++) = i;
+  }
+  *(p++) = '+';
+  *(p++) = '/';
+}
+
 // Quick and dirty query size of terminal, doesn't do ANSI probe fallback.
 // set x=80 y=25 before calling to provide defaults. Returns 0 if couldn't
 // determine size.
diff --git a/toys/other/base64.c b/toys/other/base64.c
new file mode 100644
index 00000000..7dc61147
--- /dev/null
+++ b/toys/other/base64.c
@@ -0,0 +1,87 @@
+/* base64.c - Encode and decode base64
+ *
+ * Copyright 2014 Rob Landley <rob@landley.net>
+ *
+ * No standard
+
+USE_BASE64(NEWTOY(base64, "diw#<1[!dw]", TOYFLAG_USR|TOYFLAG_BIN))
+
+config BASE64
+  bool "base64"
+  default y
+  help
+    usage: base64 [-di] [-w COLUMNS] [FILE...]
+
+    Encode or decode in base64.
+
+    -d	decode
+    -i	ignore non-alphabetic characters
+    -w	wrap output at COLUMNS (default 76)
+*/
+
+#define FOR_base64
+#include "toys.h"
+
+GLOBALS(
+  long columns;
+)
+
+static void do_base64(int fd, char *name)
+{
+  int out = 0, bits = 0, x = 0, i, len;
+  char *buf = toybuf+128;
+
+  for (;;) {
+    if (!(len = xread(fd, buf, sizeof(toybuf)-128))) {
+      if (!(toys.optflags & FLAG_d)) {
+        if (bits) {
+          putchar(toybuf[out<<(6-bits)]);
+          x++;
+        }
+        while (x++&3)  putchar('=');
+        if (x != 1) xputc('\n');
+      }
+
+      return;
+    }
+    for (i=0; i<len; i++) {
+      if (toys.optflags & FLAG_d) {
+        if (buf[i] == '=') return;
+
+        if ((x = stridx(toybuf, buf[i])) != -1) {
+          out = (out<<6) + x;
+          bits += 6;
+          if (bits >= 8) {
+            putchar(out >> (bits -= 8));
+            out &= (1<<bits)-1;
+            if (ferror(stdout)) perror_exit(0);
+          }
+
+          continue;
+        }
+        if (buf[i] == '\n' || (toys.optflags & FLAG_i)) continue;
+
+        break;
+      } else {
+        out = (out<<8) + buf[i];
+        bits += 8;
+        while (bits >= 6) {
+          putchar(toybuf[out >> (bits -= 6)]);
+          out &= (1<<bits)-1;
+          if (TT.columns == ++x) {
+            xputc('\n');
+            x = 0;
+          }
+        }
+      }
+    }
+  }
+}
+
+void base64_main(void)
+{
+  if (!TT.columns) TT.columns = 76;
+
+  base64_init(toybuf);
+  loopfiles(toys.optargs, do_base64);
+}
diff --git a/toys/posix/uuencode.c b/toys/posix/uuencode.c
index 2323c98d..ca3f10d3 100644
--- a/toys/posix/uuencode.c
+++ b/toys/posix/uuencode.c
@@ -28,16 +28,7 @@ void uuencode_main(void)
 
   if (toys.optc > 1) fd = xopen(toys.optargs[0], O_RDONLY);
 
-  // base64 table
-
-  p = toybuf;
-  for (i = 'A'; i != ':'; i++) {
-    if (i == 'Z'+1) i = 'a';
-    if (i == 'z'+1) i = '0';
-    *(p++) = i;
-  }
-  *(p++) = '+';
-  *(p++) = '/';
+  base64_init(toybuf);
 
   xprintf("begin%s 744 %s\n", m ? "-base64" : "", name);
   for (;;) {