Jean-Philippe Barrette-LaPierre provided his patch that introduces

CURLOPT_DEBUGFUNCTION and CURLOPT_DEBUGDATA.

include/curl/curl.h

@@ -101,6 +101,23 @@ typedef int (*curl_passwd_callback)(void *clientp,
                                     char *buffer,
                                     int buflen);
 
+/* the kind of data that is passed to information_callback*/
+typedef enum {
+  CURLINFO_TEXT = 0,
+  CURLINFO_HEADER_IN,    /* 1 */
+  CURLINFO_HEADER_OUT,   /* 2 */
+  CURLINFO_DATA_IN,      /* 3 */
+  CURLINFO_DATA_OUT,     /* 4 */
+  CURLINFO_END
+} curl_infotype;
+
+typedef int (*curl_debug_callback)
+       (CURL *handle,      /* the handle/transfer this concerns */
+        curl_infotype type, /* what kind of data */
+        char *data,        /* points to the data */
+        size_t size,       /* size of the data pointed to */
+        void *userp);      /* whatever the user please */
+  
 /* All possible error codes from all sorts of curl functions. Future versions
    may return other values, stay prepared.
 
@@ -513,6 +530,12 @@ typedef enum {
   /* send linked-list of pre-transfer QUOTE commands (Wesley Laxton)*/
   CINIT(PREQUOTE, OBJECTPOINT, 93),
 
+  /* set the debug function */
+  CINIT(DEBUGFUNCTION, FUNCTIONPOINT, 94),
+
+  /* set the data for the debug function */
+  CINIT(DEBUGDATA, OBJECTPOINT, 95),
+  
   CURLOPT_LASTENTRY /* the last unusued */
 } CURLoption;
 

lib/ftp.c

@@ -301,11 +301,8 @@ int Curl_GetFTPResponse(char *buf,
             CURLcode result;
 
             /* output debug output if that is requested */
-            if(data->set.verbose) {
-              fputs("< ", data->set.err);
-              fwrite(line_start, perline, 1, data->set.err);
-              /* no need to output LF here, it is part of the data */
-            }
+            if(data->set.verbose)
+              Curl_debug(data, CURLINFO_HEADER_IN, line_start, perline);
 
             /*
              * We pass all response-lines to the callback function registered
@@ -2080,15 +2077,13 @@ CURLcode Curl_ftpsendf(struct connectdata *conn,
   ssize_t write_len;
   char *sptr=s;
   CURLcode res = CURLE_OK;
+  size_t len;
 
   va_list ap;
   va_start(ap, fmt);
   vsnprintf(s, 250, fmt, ap);
   va_end(ap);
   
-  if(conn->data->set.verbose)
-    fprintf(conn->data->set.err, "> %s\n", s);
-
   strcat(s, "\r\n"); /* append a trailing CRLF */
 
   bytes_written=0;
@@ -2101,6 +2096,9 @@ CURLcode Curl_ftpsendf(struct connectdata *conn,
     if(CURLE_OK != res)
       break;
 
+    if(conn->data->set.verbose)
+      Curl_debug(conn->data, CURLINFO_HEADER_OUT, sptr, bytes_written);
+
     if(bytes_written != write_len) {
       write_len -= bytes_written;
       sptr += bytes_written;

lib/http.c

@@ -133,12 +133,6 @@ CURLcode add_buffer_send(int sockfd, struct connectdata *conn, send_buffer *in,
   char *ptr;
   int size;
 
-  if(conn->data->set.verbose) {
-    fputs("> ", conn->data->set.err);
-    /* this data _may_ contain binary stuff */
-    fwrite(in->buffer, in->size_used, 1, conn->data->set.err);
-  }
-
   /* The looping below is required since we use non-blocking sockets, but due
      to the circumstances we will just loop and try again and again etc */
 
@@ -150,6 +144,10 @@ CURLcode add_buffer_send(int sockfd, struct connectdata *conn, send_buffer *in,
     if(CURLE_OK != res)
       break;
 
+    if(conn->data->set.verbose)
+      /* this data _may_ contain binary stuff */
+      Curl_debug(conn->data, CURLINFO_DATA_OUT, ptr, amount);
+
     if(amount != size) {
       size -= amount;
       ptr += amount;
@@ -364,11 +362,8 @@ CURLcode Curl_ConnectHTTPProxyTunnel(struct connectdata *conn,
                the line isn't really terminated until the LF comes */
 
             /* output debug output if that is requested */
-            if(data->set.verbose) {
-              fputs("< ", data->set.err);
-              fwrite(line_start, perline, 1, data->set.err);
-              /* no need to output LF here, it is part of the data */
-            }
+            if(data->set.verbose)
+              Curl_debug(data, CURLINFO_DATA_IN, line_start, perline);
             
             if('\r' == line_start[0]) {
               /* end of headers */

lib/sendf.c

@@ -135,10 +135,11 @@ void Curl_infof(struct SessionHandle *data, const char *fmt, ...)
 {
   va_list ap;
   if(data->set.verbose) {
+    char print_buffer[1024 + 1];
     va_start(ap, fmt);
-    fputs("* ", data->set.err);
-    vfprintf(data->set.err, fmt, ap);
+    vsnprintf(print_buffer, 1024, fmt, ap);
     va_end(ap);
+    Curl_debug(data, CURLINFO_TEXT, print_buffer, strlen(print_buffer));
   }
 }
 
@@ -174,9 +175,6 @@ CURLcode Curl_sendf(int sockfd, struct connectdata *conn,
   if(!s)
     return CURLE_OUT_OF_MEMORY; /* failure */
 
-  if(data->set.verbose)
-    fprintf(data->set.err, "> %s", s);
-
   bytes_written=0;
   write_len = strlen(s);
   sptr = s;
@@ -188,6 +186,9 @@ CURLcode Curl_sendf(int sockfd, struct connectdata *conn,
     if(CURLE_OK != res)
       break;
 
+    if(data->set.verbose)
+      Curl_debug(data, CURLINFO_DATA_OUT, sptr, bytes_written);
+
     if(bytes_written != write_len) {
       /* if not all was written at once, we must advance the pointer, decrease
          the size left and try again! */
@@ -380,6 +381,27 @@ int Curl_read(struct connectdata *conn,
   return CURLE_OK;
 }
 
+/* return 0 on success */
+int Curl_debug(struct SessionHandle *data, curl_infotype type,
+               char *ptr, size_t size)
+{
+  static const char * const s_infotype[CURLINFO_END] = {
+    "* ", "< ", "> ", "{ ", "} " };
+
+  if(data->set.fdebug)
+    return (*data->set.fdebug)(data, type, ptr, size,
+                               data->set.debugdata);
+
+  if(type >= CURLINFO_DATA_IN)
+    /* don't do the data parts now */
+    return 0;
+
+  fwrite(s_infotype[type], 2, 1, data->set.err);
+  fwrite(ptr, size, 1, data->set.err);
+
+  return 0;
+}
+
 
 /*
  * local variables:

lib/sendf.h

@@ -53,4 +53,9 @@ CURLcode Curl_write(struct connectdata *conn, int sockfd,
                     void *mem, size_t len,
                     ssize_t *written);
 
+/* the function used to output verbose information */
+int Curl_debug(struct SessionHandle *handle, curl_infotype type,
+               char *data, size_t size);
+
+
 #endif

lib/url.c

@@ -804,12 +804,29 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option, ...)
      */
     data->set.set_resume_from = va_arg(param, long);
     break;
+  case CURLOPT_DEBUGFUNCTION:
+    /*
+     * stderr write callback.
+     */
+    data->set.fdebug = va_arg(param, curl_debug_callback);
+    /*
+     * if the callback provided is NULL, it'll use the default callback
+     */
+    break;
+  case CURLOPT_DEBUGDATA:
+    /*
+     * Set to a void * that should receive all error writes. This
+     * defaults to CURLOPT_STDERR for normal operations.
+     */
+    data->set.debugdata = va_arg(param, void *);
   case CURLOPT_STDERR:
     /*
      * Set to a FILE * that should receive all error writes. This
      * defaults to stderr for normal operations.
      */
     data->set.err = va_arg(param, FILE *);
+    if(!data->set.err)
+      data->set.err = stderr;
     break;
   case CURLOPT_HEADERFUNCTION:
     /*
@@ -2265,13 +2282,13 @@ static CURLcode CreateConnection(struct SessionHandle *data,
   {
     struct in_addr in;
     (void) memcpy(&in.s_addr, &conn->serv_addr.sin_addr, sizeof (in.s_addr));
-    infof(data, "Connected to %s (%s)\n", conn->hostaddr->h_name,
+    infof(data, "Connected to %s (%s) port %d\n", conn->hostaddr->h_name,
 #if defined(HAVE_INET_NTOA_R)
-          inet_ntoa_r(in, ntoa_buf, sizeof(ntoa_buf))
+          inet_ntoa_r(in, ntoa_buf, sizeof(ntoa_buf)),
 #else
-          inet_ntoa(in)
+          inet_ntoa(in),
 #endif
-          );
+          conn->port);
   }
 #endif
 

lib/urldata.h

@@ -553,7 +553,8 @@ struct DynamicStatic {
  */
 
 struct UserDefined {
-  FILE *err;    /* the stderr writes goes here */
+  FILE *err;         /* the stderr user data goes here */
+  void *debugdata;   /* the data that will be passed to fdebug */
   char *errorbuffer; /* store failure messages in here */
   char *proxyuserpwd;  /* Proxy <user:password>, if used */
   long proxyport; /* If non-zero, use this port number by default. If the
@@ -584,6 +585,7 @@ struct UserDefined {
   curl_write_callback fwrite_header; /* function that stores headers */
   curl_read_callback fread;          /* function that reads the input */
   curl_progress_callback fprogress;  /* function for progress information */
+  curl_debug_callback fdebug;      /* function that write informational data */
   void *progress_client; /* pointer to pass to the progress callback */
   curl_passwd_callback fpasswd;      /* call for password */
   void *passwd_client;               /* pass to the passwd callback */