X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=guestfish.pod;h=26312fe4b68cf20693f137c0a6f90e3f7b645707;hp=0870b9ee88e33dc5be48c463049f210cf6f0cf9e;hb=88da5cf8a32e683ed1d78419fcde609a389a2f65;hpb=d164ae963297a99e2222bc32b11928c1635c45d8

diff --git a/guestfish.pod b/guestfish.pod
index 0870b9e..26312fe 100644
--- a/guestfish.pod
+++ b/guestfish.pod
@@ -282,6 +282,32 @@ will create a directory C<local> on the host, and then export
 the contents of C</remote> on the mounted filesystem to
 C<local/remote-data.tar.gz>.  (See C<tgz-out>).
 
+=head1 PIPES
+
+Use C<command E<lt>spaceE<gt> | command> to pipe the output of the
+first command (a guestfish command) to the second command (any host
+command).  For example:
+
+ cat /etc/passwd | awk -F: '$3 == 0 { print }'
+
+(where C<cat> is the guestfish cat command, but C<awk> is the host awk
+program).  The above command would list all accounts in the guest
+filesystem which have UID 0, ie. root accounts including backdoors.
+Other examples:
+
+ hexdump /bin/ls | head
+ list-devices | tail -1
+
+The space before the pipe symbol is required, any space after the pipe
+symbol is optional.  Everything after the pipe symbol is just passed
+straight to the host shell, so it can contain redirections, globs and
+anything else that makes sense on the host side.
+
+To use a literal argument which begins with a pipe symbol, you have
+to quote it, eg:
+
+ echo "|"
+
 =head1 EXIT ON ERROR BEHAVIOUR
 
 By default, guestfish will ignore any errors when in interactive mode