diff -r b3f24e23bc25 -r bf54085ce341 src/c2html.h
--- a/src/c2html.h	Wed Aug 31 12:58:48 2016 +0200
+++ b/src/c2html.h	Wed Aug 31 14:41:56 2016 +0200
@@ -30,6 +30,9 @@
 #ifndef C2HTML_H
 #define	C2HTML_H
 
+#include <stdio.h>
+#include "highlighter.h"
+
 #ifdef	__cplusplus
 extern "C" {
 #endif
@@ -38,14 +41,102 @@
 #define VERSION_MINOR   0
 #define VERSION_DEVELOP 1 /* set this to zero for release version */
 
-typedef struct {
-    char* outfilename;
-    char* headerfile;
-    char* footerfile;
-    char* infilename;
-    int showlinenumbers;
-} Settings;
+/**
+ * Reads a source file from the input buffer and writes at most
+ * <code>maxlen</code> bytes of the formatted output to the output buffer.
+ * 
+ * The output buffer must either be large enough to hold <code>maxlen</code>
+ * bytes or the write function must trigger an automatic extension of the buffer.
+ * 
+ * @param inputbuffer the input buffer
+ * @param rfnc a read function operating for the input buffer
+ * @param ibuf intermediate processing buffer
+ * @param ibuflen length of intermediate processing buffer (recommended: 4 KB)
+ * @param outputbuffer the output buffer
+ * @param wfnc a write function for the output buffer
+ * @param maxlen the maximum amount bytes which will be written to the
+ * output buffer
+ * @param hltr the highlighter function
+ * @param showln zero, if line numbers shall be omitted, nonzero otherwise
+ * 
+ * @return total amount of bytes written to the output buffer
+ * 
+ * @see c2html_plain_highlighter()
+ * @see c2html_c_highlighter()
+ * @see c2html_java_highlighter()
+ */
+size_t c2html_formatn(void* inputbuffer, read_func rfnc,
+        char* ibuf, size_t ibuflen, void* outputbuffer, write_func wfnc,
+        size_t maxlen, c2html_highlighter_func hltr, int showln);
+    
+/**
+ * Reads a source file from the input buffer and writes the formatted output
+ * to an output buffer.
+ * 
+ * The output buffer must either be large enough to hold the formatted data
+ * or the write function must trigger an automatic extension of the buffer.
+ * 
+ * @param inputbuffer the input buffer
+ * @param rfnc a read function operating for the input buffer
+ * @param ibuf intermediate processing buffer
+ * @param ibuflen length of intermediate processing buffer (recommended: 4 KB)
+ * @param outputbuffer the output buffer
+ * @param wfnc a write function for the output buffer
+ * @param hltr the highlighter function
+ * @param showln zero, if line numbers shall be omitted, nonzero otherwise
+ * 
+ * @return total amount of bytes written to the output buffer
+ * 
+ * @see c2html_plain_highlighter()
+ * @see c2html_c_highlighter()
+ * @see c2html_java_highlighter()
+ */
+size_t c2html_format(void* inputbuffer, read_func rfnc,
+        char* ibuf, size_t ibuflen, void* outputbuffer, write_func wfnc,
+        c2html_highlighter_func hltr, int showln);
 
+/**
+ * Reads a source file from the specified input file stream and writes the
+ * formatted output to an output buffer.
+ * 
+ * The output buffer must either be large enough to hold the formatted data
+ * or the write function must trigger an automatic extension of the buffer.
+ * 
+ * @param inputfile the input file stream
+ * @param ibuf intermediate processing buffer
+ * @param ibuflen length of intermediate processing buffer (recommended: 4 KB)
+ * @param outputbuffer the output buffer
+ * @param wfnc a write function for the output buffer
+ * @param hltr the highlighter function
+ * @param showln zero, if line numbers shall be omitted, nonzero otherwise
+ * 
+ * @return total amount of bytes written to the output buffer
+ * 
+ * @see c2html_plain_highlighter()
+ * @see c2html_c_highlighter()
+ * @see c2html_java_highlighter()
+ */
+size_t c2html_format_file(FILE* inputfile, char *ibuf, size_t ibuflen,
+        void* outputbuffer, write_func wfnc,
+        c2html_highlighter_func hltr, int showln);
+
+/**
+ * Reads a source file from the specified input file stream and directly writes
+ * the formatted output to the output file stream.
+ * 
+ * @param inputfile the input file stream
+ * @param ibuf intermediate processing buffer
+ * @param ibuflen length of intermediate processing buffer (recommended: 4 KB)
+ * @param outputfile the output file stream
+ * @param hltr the highlighter function
+ * @param showln zero, if line numbers shall be omitted, nonzero otherwise
+ * 
+ * @see c2html_plain_highlighter()
+ * @see c2html_c_highlighter()
+ * @see c2html_java_highlighter()
+ */
+void c2html_fformat_file(FILE *inputfile, char *ibuf, size_t ibuflen,
+        FILE* outputfile, c2html_highlighter_func hltr, int showln);
 
 #ifdef	__cplusplus
 }