Initial Commit

.svn/pristine/94/94c67c2b5f60ab3609a422ba324253b96434007a.svn-base

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+/* BLOCKIO.C - Routines to read/write blocks of bits from/to a text file. */
+
+/* Copyright (c) 1995-2012 by Radford M. Neal.
+ *
+ * Permission is granted for anyone to copy, use, modify, and distribute
+ * these programs and accompanying documents for any purpose, provided
+ * this copyright notice is retained and prominently displayed, and note
+ * is made of any changes made to these programs.  These programs and
+ * documents are distributed without any warranty, express or implied.
+ * As the programs were written for research purposes only, they have not
+ * been tested to the degree that would be advisable in any important
+ * application.  All use of these programs is entirely at the user's own
+ * risk.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "blockio.h"
+
+
+int blockio_flush = 0;	/* Should blocks written be immediately flushed? */
+
+
+/* READ A BLOCK OF BITS.  The bits must be given as '0' or '1' characters,
+   with whitespace allowed (but not required) between bits.  Returns 0 if
+   a block is read successfully, and EOF if eof or an error occurs.  If
+   EOF is returned, a warning will be printed if a partial block had already
+   been read. */
+
+int blockio_read
+( FILE *f,    /* File to read from */
+  char *b,    /* Place to store bits read */
+  int l       /* Length of block */
+)
+{
+  int i, c;
+
+  for (i = 0; i<l; i++)
+  { 
+    do
+    { c = getc(f);
+      if (c==EOF) 
+      { if (i>0)
+        { fprintf(stderr,
+           "Warning: Short block (%d long) at end of input file ignored\n",i);
+        }
+        return EOF;
+      }
+    } while (c==' ' || c=='\t' || c=='\n' || c=='\r');
+
+    if (c!='0' && c!='1')
+    { fprintf(stderr,"Bad character in binary file (not '0' or '1')\n");
+      exit(1);
+    }
+
+    b[i] = c=='1';
+  }
+
+  return 0;
+}
+
+
+/* WRITE A BLOCK OF BITS.  Bits are written as '0' and '1' characters, with
+   no spaces between them, followed by a newline. */
+
+void blockio_write
+( FILE *f,     /* File to write to */
+  char *b,     /* Block of bits to write */
+  int l        /* Length of block */
+)
+{ 
+  int i;
+
+  for (i = 0; i<l; i++)
+  { if (b[i]!=0 && b[i]!=1) abort();
+    putc("01"[b[i]],f);
+  }
+
+  putc('\n',f);
+
+  if (blockio_flush)
+  { fflush(f);
+  }
+}