.TH SETDB 1 "3 April 1995" "MIT DB software 9.3" "DB applications"
.SH NAME
setdb, cshsetdb, dossetdb \- set DB environment variables
.SH SYNOPSIS
\fB\&. setdb
.br
source cshsetdb
.br
dossetdb\fR
.SH DESCRIPTION
.SS \fIsh\fR, \fIbash\fR, and \fIksh\fR shell users:
\fIsetdb\fR sets the shell variables \fBDB\fR and \fBDBCAL\fR to the
appropriate values to permit access to on-line ECG databases.  It must be
executed using the ``.'' as shown above.  A frequent user of the databases
will find it convenient to include an invocation of \fIsetdb\fR in
the \fI.profile\fR file.
.SS \fIcsh\fR and \fItcsh\fR users:
\fIcshsetdb\fR sets \fBDB\fR and \fBDBCAL\fR similarly for the C-shell.  It
must be executed using ``source'' as shown above.  It may be convenient to
include this command in the \fI.cshrc\fR file.
.SS MS-DOS users:
\fIdossetdb\fR sets \fBDB\fR and \fBDBCAL\fR similarly for MS-DOS;  it also
sets \fBVIEWP\fR (see \fIview\fR(1)).  It may be convenient to include this
command in the \fIautoexec.bat\fR file (under MS-DOS 3.3 and later, include
the command ``call dossetdb'' within \fIautoexec.bat\fR;  under earlier
versions of MS-DOS, use ``command /c dossetdb'', or append the contents of
\fIdossetdb.bat\fR to \fIautoexec.bat\fR).
.PP
These programs are shell scripts that must be customized
before using them for the first time on a new machine.
.SH ENVIRONMENT
.TP
\fBDB\fR
The database path: a list of directories that contain database files.  An
empty component is taken to refer to the current directory.  All applications
built with the \fIdb\fR(3) library search for their database input files in
the order specified by \fBDB\fR.  If \fBDB\fR is not set, searches are limited
to the current directory.  Under UNIX, directory names are separated by colons
(:), and the format of \fBDB\fR is that of the Bourne shell's \fBPATH\fR
variable (see \fIsh\fR(1)).  Under MS-DOS, directory names are separated by
semicolons (;), and the format of \fBDB\fR is that of the MS-DOS \fBPATH\fR
variable (colons may be used following drive specifiers within \fBDB\fR in this
case).  The Macintosh does not support environment variables as such;  on the
Macintosh, the value of \fBDB\fR is defined in \fIdblib.h\fR (one of the DB
library source files, not usually included in DB applications), and it contains
a semicolon-delimited list of directories (folders) as under MS-DOS, but with
colons used as directory separators rather than backslashes as under MS-DOS.
Under any environment, if the value of \fBDB\fR begins with `@', the remainder
of the string is taken as the name of an ``indirect DB path file'' that
defines the database path in the format described above.  This feature was
introduced in DB library version 8.0, mainly to permit Macintosh users to
modify the DB path without recompiling the DB library, but it is also useful
under MS-DOS to avoid the 128-character limit on the length of environment
variables.  Indirect DB path files can be nested up to 10 levels deep.
.TP
\fBDBCAL\fR
The name of the DB calibration file (see \fIdbcal\fR(5)).  The usual rules for
finding DB files by searching the DB path apply to the DB calibration file,
so the value of \fBDBCAL\fR need not be an absolute path name.  The DB
calibration file is used by DB applications that need to plot signals at
standard scales, as well as by \fIcalibrate\fR(1), which can determine the
baseline and gain of signals if calibration pulses are present and if the
parameters of the calibration pulses are described in the calibration file.
If \fBDBCAL\fR is not set by the user, the DB library uses a default DB
calibration file (\fIdbcal\fR, named in \fIdblib.h\fR).  If the DB calibration
file is not readable, programs that rely on it may not choose appropriate
scales for some types of signals.