.Dd 17 May, 2015
.Dt GENPATCH 1      
.Os
.Sh NAME
.Nm genpatch
.Nd generate patch quickly in standard FreeBSD ports format
.Sh SYNOPSIS             
.Nm
.Ar newfile
.Nm
.Ar oldfile
.Ar newfile
.Sh DESCRIPTION    
This utility is always called by
.Xr portfix 1 ,
but quite often it is useful in its own right.

It creates patches using the standard FreeBSD ports format defined by the "make makepatch"
ports utility, but there are different operational modes.

If
.Nm
is called when the current working directory is a subdirectory of WRKDIRPREFIX if defined
or PORTSDIR if not, then a patch will be saved in the current directory using the naming
standard used by "make makepatch".  Note that the utility assumes that it has been executed
in the WRKSRC directory, the standard location for applying ports patches.

If
.Nm
is executed outside of WRKDIRPREFIX (or PORTSDIR), then a patch will not be created.  The 
contents of the patch will be send to stdout, so the user will have to direct it to a
file manually as desired.

If only one argument is given,
.Nm
will search for a file named "<newfile>.intermediate" and if found, it will generated diff
output between it and
.Op newfile .
If that file doesn't exist, it will search for "<newfile>.orig" and attempt to create diff
output between it and
.Op newfile .
.Pp
.Sh ERRORS
.Nm
will abort if no arguments or more than 2 arguments are given.  If only one argument (
.Op newfile
) is given, then a regular file called "<newfile>.orig" or "<newfile>.intermediate"
must exist otherwise
.Nm
will abort.  If two arguments are given, both must be existing regular files.
.Pp
.Sh ENVIRONMENT
.Bl -tag -width "PORTEDITOR" -indent 
.It Ev WORKTREE
Overrides hardcoded WRKDIRPREFIX (or PORTSDIR).  This is useful for ports outside of the tree
or when
.Nm
was installed via binary packages and WRKDIRPREFIX is defined (or PORTSDIR is non-standard)
.Pp
.Sh NOTES
.Bl -enum -compact
.It 
FreeBSD does not set WRKDIRPREFIX by default
.It
The default PORTSDIR for FreeBSD is
.Pa /usr/ports
so on standard FreeBSD systems
.Nm
will generate a patch file in the current directory if executed on any subdirectory of
.Pa /usr/ports .
.It
Dragonfly sets WRKDIRPREFIX to
.Pa /usr/obj/dports
by default, so on standard systems patch
files are generated automatically if
.Nm
is executed from a subdirectory of
.Pa /usr/obj/dports . 
.It
The root directory used for this calculation is permanently set when
.Nm
is built, but it can be overridden with the WORKTREE environment variable.
.El
.Pp
.Sh SEE ALSO 
.Xr dupe 1 , 
.Xr portfix 1