Introduce usagef() that takes a printf-style format

diff --git a/convert.c b/convert.c
index 1816e977b7b13782003fc78a9de9b47cd3554a32..491e7141b4ea29b3cf754cbaf2656a0c3ca8c46c 100644 (file)
--- a/convert.c
+++ b/convert.c
@@ -267,7 +267,7 @@ static int filter_buffer(int fd, void *data)
 
        status = finish_command(&child_process);
        if (status)
-               error("external filter %s failed %d", params->cmd, -status);
+               error("external filter %s failed %d", params->cmd, status);
        return (write_err || status);
 }