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.Dd Apr 26, 2017
.Dt FEATHERS 1
.Os
.Sh NAME
.Nm feathers
.Nd a simple source-level debugger for CHICKEN Scheme
.Sh SYNOPSIS
.Nm
.Op Ar OPTION ...
.Op Ar PROGRAM Ar ARGUMENTS ...
.Sh DESCRIPTION
.Nm
runs a program compiled with CHICKEN Scheme and allows basic
source-level debugging like setting breakpoints, single-stepping and
inspection of procedure arguments and global variables.
.Pp
The Scheme code must be compiled with debug-level 3 for debugging to be
possible. Communication with the debugger takes place by exchanging
messages over a TCP socket, the address and port being given by the
environment variable
.Ev CHICKEN_DEBUGGER
which holds a connection address of the form
.Ao ADDRESS Ac : Ns Ao PORT Ac .
.Pp
.Ar PROGRAM
must give the path to the executable that is to be run,
.Ev PATH 
is not searched.
.Pp
The program accepts following arguments:
.Bl -tag -width Ds
.It Fl help
Shows a list of supported command-line options.
.It Fl n
Do not load the default startup file
.Pa .feathers .
.It Fl d
TODO: Document this
.It Fl dir Ar DIRECTORY
Add
.Ar DIRECTORY
to the list of searched paths for locating source files.
.It Fl port Ar PORT
Select a different TCP port than the default
.Pq 9999 .
.El
.Sh ENVIRONMENT
The following environment variables change the behaviour of
.Nm Ns :
.Bl -tag -width CHICKEN_DEBUGGER
.It Ev CHICKEN_DEBUGGER
Should hold a TCP server address and port where the debugger is listening.
This variable is set by the debugger when a program is run from it, and
defaults to localhost:9999
.El
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr chicken 1 ,
.Xr csc 1 ,
.Xr csi 1
.Pp
More information can be found in the
.Lk http://wiki.call-cc.org/manual/index "CHICKEN User's Manual".
.Sh AUTHORS
.An The CHICKEN Team
.Sh BUGS
Submit bug reports by e-mail to
.Mt chicken-janitors@nongnu.org