X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Ffwrite.c;h=3c40186500a88ceac20eed0e02989a2d5ab7d113;hb=55cf35957bf8dec0a489ba758c02c83303a5eb50;hp=4eece021380b9a43ed0925fa3a9f2c6784e1cca9;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec;p=pdclib

diff --git a/functions/stdio/fwrite.c b/functions/stdio/fwrite.c
index 4eece02..3c40186 100644
--- a/functions/stdio/fwrite.c
+++ b/functions/stdio/fwrite.c
@@ -1,8 +1,101 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-size_t fwrite( const void * restrict ptr, size_t size, size_t nelem, FILE * restrict stream ) { /* TODO */ };
+/* $Id$ */
+
+/* fwrite( const void *, size_t, size_t, FILE * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <stdio.h>
+#include <_PDCLIB_glue.h>
+
+#ifndef REGTEST
+
+#include <stdbool.h>
+#include <string.h>
+
+size_t fwrite( const void * _PDCLIB_restrict ptr, size_t size, size_t nmemb, struct _PDCLIB_file_t * _PDCLIB_restrict stream )
+{
+    if ( _PDCLIB_prepwrite( stream ) == EOF )
+    {
+        return 0;
+    }
+    _PDCLIB_size_t offset = 0;
+    bool lineend = false;
+    size_t nmemb_i;
+    for ( nmemb_i = 0; nmemb_i < nmemb; ++nmemb_i )
+    {
+        for ( size_t size_i = 0; size_i < size; ++size_i )
+        {
+            /* TODO: Should line-buffered streams be flushed on '\n' or system EOL? */
+            if ( ( stream->buffer[ stream->bufidx++ ] = ((char*)ptr)[ nmemb_i * size + size_i ] ) == '\n' )
+            {
+                /* Remember last newline, in case we have to do a partial line-buffered flush */
+                offset = stream->bufidx;
+                lineend = true;
+            }
+            if ( stream->bufidx == stream->bufsize )
+            {
+                if ( _PDCLIB_flushbuffer( stream ) == EOF )
+                {
+                    /* Returning number of objects completely buffered */
+                    return nmemb_i;
+                }
+                lineend = false;
+            }
+        }
+    }
+    /* Fully-buffered streams are OK. Non-buffered streams must be flushed,
+       line-buffered streams only if there's a newline in the buffer.
+    */
+    switch ( stream->status & ( _IONBF | _IOLBF ) )
+    {
+        case _IONBF:
+            if ( _PDCLIB_flushbuffer( stream ) == EOF )
+            {
+                /* We are in a pinch here. We have an error, which requires a
+                   return value < nmemb. On the other hand, all objects have
+                   been written to buffer, which means all the caller had to
+                   do was removing the error cause, and re-flush the stream...
+                   Catch 22. We'll return a value one short, to indicate the
+                   error, and can't really do anything about the inconsistency.
+                */
+                return nmemb_i - 1;
+            }
+            break;
+        case _IOLBF:
+            {
+            size_t bufidx = stream->bufidx;
+            stream->bufidx = offset;
+            if ( _PDCLIB_flushbuffer( stream ) == EOF )
+            {
+                /* See comment above. */
+                stream->bufidx = bufidx;
+                return nmemb_i - 1;
+            }
+            stream->bufidx = bufidx - offset;
+            memmove( stream->buffer, stream->buffer + offset, stream->bufidx );
+            }
+    }
+    return nmemb_i;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    FILE * fh;
+    remove( testfile );
+    TESTCASE( ( fh = fopen( testfile, "w" ) ) != NULL );
+    TESTCASE( fwrite( "SUCCESS testing fwrite()\n", 1, 25, fh ) == 25 );
+    TESTCASE( fclose( fh ) == 0 );
+    /* TODO: Add readback test. */
+    TESTCASE( remove( testfile ) == 0 );
+    return TEST_RESULTS;
+}
+
+#endif
+