a CURLOPT_PROGRESSFUNCTION clarification

diff --git a/docs/libcurl/curl_easy_setopt.3 b/docs/libcurl/curl_easy_setopt.3
index 6ac538a7a75a454f303574078f6d82435d14013d..6be387d11858a34400a0e093198846a9473e3618 100644 (file)
--- a/docs/libcurl/curl_easy_setopt.3
+++ b/docs/libcurl/curl_easy_setopt.3
@@ -169,11 +169,12 @@ added in 7.12.3)
 .IP CURLOPT_PROGRESSFUNCTION
 Function pointer that should match the \fIcurl_progress_callback\fP prototype
 found in \fI<curl/curl.h>\fP. This function gets called by libcurl instead of
-its internal equivalent with a frequent interval during data transfer (roughly
-once per second).  Unknown/unused argument values pass to the callback will be
-set to zero (like if you only download data, the upload size will remain
-0). Returning a non-zero value from this callback will cause libcurl to abort
-the transfer and return \fICURLE_ABORTED_BY_CALLBACK\fP.
+its internal equivalent with a frequent interval during operation (roughly
+once per second) no matter if data is being transfered or not.  Unknown/unused
+argument values passed to the callback will be set to zero (like if you only
+download data, the upload size will remain 0). Returning a non-zero value from
+this callback will cause libcurl to abort the transfer and return
+\fICURLE_ABORTED_BY_CALLBACK\fP.
 
 If you transfer data with the multi interface, this function will not be
 called during periods of idleness unless you call the appropriate libcurl