The optional parameter DBname specifies the name of the database to be used.
If it is omitted then BROWSE prompts for it. A ? in response to
the prompt lists the currently available databases.
The optional SAMPLE and INDEX are entered if the user wants to
concentrate on a subset of a database. If they are omitted, then the default
sample which contains all valid records in the database is used.
The following example is the start of a BROWSE session (in which the user
begins from the xray account):
HEASARC> browse me
BROWSE 3.00: 31-AUG-90 14:27:37 CET. Address=SCIVAX::INEWTON (XRAY)
For further information type HELP, KEYWORDS or DATABASES (to end use EXIT)
Loading ME database sample TOTAL indexed on DEC
ME_TOTAL_DEC >
The prompt ME_TOTAL_DEC > indicates that BROWSE is ready to receive a
command. It also indicates the current database, ME, the current sample,
TOTAL, and the current index, DEC.
From within BROWSE, the command help is used to access a description
about each command. Typing help alone will list a summary of all commands;
hitting carriage return will exit the help.
Typing help <command> will go directly to the help for the command specified
by <command>.
A description of the current database can be obtained using dbhelp.
This contains a complete description of each database, including
each parameter, the available data products, and the name of a contact
person. There are the following three qualifiers for the dbhelp command:
/DBNAME /GENERAL /OBSERVATORY
The /dbname qualifier allows the description of other databases to be
accessed; /general gives an overview of how the databases are structured;
and /observatory gives a description of the observatory for
the current database.
The current status of BROWSE can be ascertained at any time using the
show command. This lists the current database, sample, and environment,
the number of entries in the sample, if and how a subsample has been created,
and many other details.
Many COMMAND names are acronyms based on the first initial of the word in the
command description. The first word, in most cases, describes the action to be
performed and the following word(s) describe the item(s) upon which to act,
such as, Change Database - cdb, or Search in a Cone - sc.
A number of keywords have been created to help the user navigate to the
required command. These keywords are listed by typing ? on
the BROWSE command line. The commands associated with each keyword
are listed by typing the keyword. For example, typing search on the command
line lists all commands that make, or are associated with searching a table.
A full summary of all commands is obtained by typing ??, but can produce
a rather daunting list.
such as cdb cma or sc/def or sp/full pi smith
All command, qualifier, and option names can be abbreviated to the minimum
number of characters required to make each unique. Commands are not case
sensitive.
Command strings can be up to 255 characters long. They are continued beyond the
current line by typing a hyphen followed by carriage return -<cr>.
The qualifiers control how a command is executed. They are similar to those
used in VAX/VMS; but, unlike VMS, spaces are not allowed between the qualifiers,
nor between the command and the first qualifier.
The available qualifiers can be listed by using /?, as for example, sc/?
The positional parameters control the item that the command is to operate
upon. These can be
a database record number (or range of numbers)
one or more database parameters names
a file name
a device name.
Each parameter is separated by a space. If the parameter to be entered has
spaces and more than the first word is required to specify it uniquely,
then it must be enclosed in double quotes, such as ``QFLAG ME".
If the parameter is numerical and a range of numbers is possible, these
can be specified as 1-10 or 15-300. The maximum possible value of a
numeric range can be specified using **, as for example, 1-**.
If the required command option or qualifier is not given on the command
line, then the user will be prompted for the information.
If the user is asked for a database, sample, index, or parameter name,
then typing <cr> with no input, or a ?, produces a listing of all of those
available. For character strings, it is only necessary to specify sufficient
letters to make a unique identification. If there is a conflict, a list of
matching parameters is given and the user can enter the correct name or use
the parameter number which is listed on the right hand side.
When answering a prompt for information, exit or quit can be used to
terminate the request. Ctrl Z can also be used to abort command requests.
The last 50 BROWSE commands are saved in a stack and any of those commands can
be recalled and executed again using the recall command. If recall is typed
with no arguments it will list out the last 20 commands. The required command
is re-executed by typing recall n where n is the command number. Commands
from previous sessions are also saved and are given a negative command number.
Each command for a given session is given an increasing number.
The current command number can be established by using the prompt command.
This will toggle the BROWSE prompt from the default which describes the current
database, sample, and index to a more simple [N]BROWSE> prompt, where N is
the current command number.
Up to ten different commands can be typed on the same command string simply
by separating them by the symbol ;. All commands are then executed in
sequence.
Any string entered on the command line can be aliased to another name by the
user. This is very useful for shortening a long, complex string to a concise
easy to remember phrase. The command
alias command command_string
makes command to represent command_string. Following this, whenever
command is typed on the command line, the original command_string is
executed. The command previously given can also be renamed if the
/previous qualifier is given and this allows the user to check that the
command works before giving it an alias name. All alias names are saved for
future sessions.
There are system-defined and user-defined aliases. The former are useful
aliases provided for all users. A listing of the system aliases is obtained
using alias/show. The additional qualifier /system or /user is used to
restrict the listing to the system or user aliases. There is currently a
maximum of 100 user and 100 system aliases.
All output to the screen can be written to a log file. The file is specified
using the command log filename, where filename is the name of the file.
The file is automatically given the extension .log. If the filename
is prefixed with a +, then the output is appended to an existing
file. Subsequent log commands close an existing log file and open a
new one.
BROWSE commands can be written into an ASCII file and then invoked during a
BROWSE session by using an @ symbol in front of the file name. The
default extension for these files is .xco. Comments can be included in
the file if they are prefixed with an exclamation mark !.
A script file can be created from BROWSE using the script filename
command. Following this, all BROWSE commands are echoed to the file defined
by filename. This file will have the extension .xco. It can then
be used at a later date to reproduce the BROWSE session. It also provides a
useful way of reporting bugs. If BROWSE crashes, or gives a wrong result,
open a script file and repeat the command sequence. MAIL the file
along with either a report of the bug, or with the corresponding log file.
The dir command lists the files contained in the user's current
directory. This can be used to keep track of files created and extracted
using BROWSE. The file types and extensions can be specified. Wild cards
can be used as, for example, dir *.pha lists all .pha files.
