amixer: document --file option in man page

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/amixer/amixer.1 b/amixer/amixer.1
index 8860ae184e20ba4763c203e6dcfb89612d470b7f..f825aa3c2aba145902b5b81b27a2419ad52fd79c 100644 (file)
--- a/amixer/amixer.1
+++ b/amixer/amixer.1
@@ -112,6 +112,15 @@ When this option is given, the command in command\-line arguments is ignored.
 Only sset and cset are accepted.  Other commands are ignored.
 The commands to unmatched ids are ignored without errors too.
 
+.TP
+\fI\-f\fP file | \fI\-\-file\fP file
+
+Read from the given file and execute the command on each line sequentially.
+When this option is given, the command in command\-line arguments is ignored.
+
+Only sset and cset are accepted.  Other commands are ignored.
+The commands to unmatched ids are ignored without errors too.
+
 .TP
 \fI\-h\fP 
 Help: show syntax.