diff -r 9f25df78925e -r 1b12cf799fee src/frontend.c
--- a/src/frontend.c	Thu Nov 10 18:44:48 2016 +0100
+++ b/src/frontend.c	Mon Apr 24 20:54:38 2023 +0200
@@ -33,9 +33,7 @@
 #include <string.h>
 
 #include "c2html.h"
-#include "ucx/utils.h"
-
-#define FILEBUF_SIZE 4096
+#include <cx/utils.h>
 
 typedef struct {
     char* outfilename;
@@ -45,20 +43,17 @@
     int showlinenumbers;
 } Settings;
 
-static int appendfile(const char *filename, FILE *fout,
-        char *copybuf, size_t copybuflen, const char *errmsg) {
-    FILE *headerfile = fopen(filename, "r");
-    if (!headerfile) {
+static int appendfile(const char *filename, FILE *fout, const char *errmsg) {
+    FILE *fin = fopen(filename, "r");
+    if (!fin) {
         perror(errmsg);
         if (fout != stdout) {
             fclose(fout);
         }
         return 1;
     }
-    ucx_stream_copy(headerfile, fout,
-            (read_func) fread, (write_func) fwrite,
-            copybuf, copybuflen, (size_t)-1);
-    fclose(headerfile);
+    cx_stream_copy(fin, fout, (cx_read_func) fread, (cx_write_func) fwrite);
+    fclose(fin);
     return 0;
 }
 
@@ -86,7 +81,7 @@
     c2html_highlighter_func hltr = c2html_c_highlighter;
 
     /* Parse command line */
-    char optc;
+    int optc;
     while ((optc = getopt(argc, argv, "hljo:pH:F:vV")) != -1) {
         switch (optc) {
             case 'o':
@@ -142,15 +137,8 @@
             fout = stdout;
         }
         
-        /* Allocate file buffer  */
-        char *filebuf = malloc(FILEBUF_SIZE);
-        if (!filebuf) {
-            perror("Error allocating file buffer");
-            return EXIT_FAILURE;
-        }
-        
         /* Prepend header file */
-        if (appendfile(settings.headerfile, fout, filebuf, FILEBUF_SIZE,
+        if (appendfile(settings.headerfile, fout,
                 "Error opening header file")) {
             return EXIT_FAILURE;
         }
@@ -158,11 +146,17 @@
         /* Process input file */
         FILE *inputfile = fopen(settings.infilename, "r");
         if (inputfile) {
-            c2html_fformatf(
-                    inputfile, filebuf, FILEBUF_SIZE,
-                    fout, hltr, settings.showlinenumbers
+            CxBuffer fbuf;
+            cxBufferInit(&fbuf, NULL, 4096, NULL, CX_BUFFER_AUTO_EXTEND);
+            cx_stream_copy(inputfile, &fbuf, (cx_read_func) fread,
+                           (cx_write_func) cxBufferWrite);
+            fclose(inputfile);
+            c2html_bformat(
+                    fbuf.space, fbuf.size,
+                    fout, (cx_write_func ) fwrite, hltr,
+                    settings.showlinenumbers
             );
-            fclose(inputfile);
+            cxBufferDestroy(&fbuf);
         } else {
             perror("Error opening input file");
             if (fout != stdout) {
@@ -172,12 +166,10 @@
         }
         
         /* Append footer file */
-        if (appendfile(settings.footerfile, fout, filebuf, FILEBUF_SIZE,
+        if (appendfile(settings.footerfile, fout,
                 "Error opening footer file")) {
             return EXIT_FAILURE;
         }
-        
-        free(filebuf);
 
         return EXIT_SUCCESS;
     }