feh(1), --version: Document libmagic compile flag

1 files changed, 12 insertions, 9 deletions

diff --git a/man/feh.pre b/man/feh.pre
index 340d6cd..1899800 100644
--- a/man/feh.pre
+++ b/man/feh.pre
@@ -41,6 +41,9 @@ libexif builtin EXIF reader $MAN_EXIF$
 .It
 inotify-based auto-reload of changed files $MAN_INOTIFY$
 .
+.It
+libmagic $MAN_MAGIC$
+.
 .El
 .
 $MAN_DEBUG$
@@ -165,20 +168,20 @@ with a non-negative value to enable support for these formats.
 .
 .Pp
 .
-As Imlib2 may take several seconds to determine whether it can load a file or
-not
-.Pq e.g. when attempting to open a large video ,
+.Pq optional feature, $MAN_MAGIC$ in this build
+.Nm
+can use libmagic to only pass image files to Imlib2.
+This feature is $MAN_MAGIC$ in this build.
+When using
 .Nm
-checks each file's header before loading it.
-If it looks like an image, it is passed on to Imlib2, otherwise, it is
-assumed to be unloadable.
-This greatly improves performance when working in directories with mixed files
-.Pq i.e., directories which do not exclusively contain image files .
+with lots of non-image files
+.Pq especially with Imlib2 version 1.6.x or 1.7.0 ,
+this can speed up the detection of non-image files significantly.
 If you think that Imlib2 can load a file which
 .Nm
 has determined to be likely not an image, set the environment variable
 .Qq FEH_SKIP_MAGIC
-to pass all files directly to Imlib2, bypassing the header check.
+to pass all files directly to Imlib2, bypassing this check.
 The environment variable's value does not matter, it just needs to be set.
 .
 .Sh OPTIONS