Provided by: gnuspool_1.7_i386
spsyntax - option handling for GNUspool programs
All of the options referred to in the descriptions of the shell-level
programs for GNUspool below may be supplied in a configuration file
(q.v.), or in an environment variable whose name is the same as the
calling program, except that it is in lower case.
This may enable defaults to be supplied according to the application
from which the program is invoked. However any options and arguments
supplied on the command line usually take priority.
Additionally by editing the appropriate message file (q.v.) it is
possible to change the option letters and keywords from those
In nearly all cases there are two alternative ways of supplying
· Via a traditional Unix-style -letter option, for example as -z.
· Via a keyword-style option, such as "+zero-charge". Keywords are
The syntax of options is intended to be as flexible as possible.
Options which do not take arguments may be grouped together as in
or they may be given separately as in
-w -m -v
White space is optional in the case of options which do take arguments,
are acceptable and have the same effect.
If the keyword version of an option is given, then it must be separated
from its argument by white space thus
To save the user from having to specify commonly-used combinations of
options, there are mechanisms enabling these to be supplied to each
One mechanism is the use of a configuration file, .gnuspool in the
current or user's home directory. The other is the use of an
These files may also be used to specify alternative message files.
The format of configuration files is akin to a set of environment
variable assignments, with empty lines and lines beginning with "#"
The name assigned to is the same as that of the calling program but in
upper case and with "-" changed to "_" (underscore), for example that
corresponding to gspl-pq is "GSPL_PQ" etc. This is the same as for the
corresponding environment variable.
Usually options are taken from the following places in order, so that
later-processed ones override earlier ones:
Each program has a set of standard defaults which are used to
initialise the parmaters when the program is invoked.
In some cases, for example default priority, the user's profile as
displayed by gspl-user(1) is used to initialise the defaults.
The file ~/.gnuspool is read, and any options specified therein
(i.e. with an assignment to the appropriate name) are interpreted.
Please note that for historical reasons the actual path is
~$LIBRARY/.gnuspool. If the environment variable "LIBRARY" is null,
then this will be equivalent to .gnuspool in the user's home
Any options specified in the appropriate environment variable (you
will almost certainly have to use quotes when setting it via the
shell in order to preserve the white space) are read and
The file .gnuspool is read, and any options specified therein (i.e.
with an assignment to the appropriate name) are interpreted.
Note that this may mean that the .gnuspool file is read twice if
the command is run from the current directory. Beware therefore of
options which are cumulative, such as arguments and redirections,
and use the "cancel existing" options.
Any options specified on the command line are interpreted last.
Most options have inverses so that it is possible to reset anything
which may have been set by previously-read options. Extra care should
be taken with cumulative options, notably arguments and redirections,
so that these are not doubled, especially in the case where the home
directory is also the current directory.
The above description of the order of selection of configuration files,
environment and command-line options is the default.
It may be desirable to change the order of selection of options, in to
eliminate some alternative locations or to include others.
The environment variable "GS_CONFIGPATH" may be set to a colon-
separated list of directories (environment variables and "~"user
constructs are appropriately interpreted).
The symbol "!" is used to represent the relevant environment variable,
and "-" is used to represent option arguments.
The default value of "GS_CONFIGPATH" is
This provides the interpretation of options in various configuration
files and the environment which is documented above.
Note that it is possible to eliminate or override the interpretation of
options on the command line by removing or relocating the "-". This may
have very surprising effects especially where configuration files wipe
out the effects of options which may have been set on the command line.
Where the interpretation of options has been removed altogether, then
any options supplied will probably be objected to or misinterpreted as
file names or similar.
and equivalents do not take into account the value of "GS_CONFIGPATH"
in any way.
Finally please note that any non-existent or inaccessible directories
and files will (usually) be silently ignored. If a configuration file
appears to exist but is inaccessible, a diagnostic may be given;
however in some cases this may be misleading due to the fact that
various versions of Unix are misleading or inconsistent with regard to
the error codes reported from an attempt to open a non-existent or
inaccessible file in a non-existent or inaccessible directory.
As well as providing help and error messages, screen key assignments
etc, message files also provide the option letters and keyword names
used to specify the options.
For each command, there is a default message file. For most of the
shell-based commands, this is sprest.help. Alternative message files
may be specified using an environment variable or configuration file
assigning values to a name. For most of the shell-based commands, this
Within the message file itself, the option letters and keywords are set
up using sequences of the form
Comments and the context should make clear which commands these options
These sequences define
A state number
The state number, in the above example 300, which is used
internally to denote the argument.
A single character, often a letter, but in the above example "?",
which is the single-character variant of the option, thus "-?".
Several option letters, each separated by commas may be defined. To
define <,> itself as an option "letter", use "\,".
A string of alphanumerics, possibly including hyphens and
underscores, is used to denote an option keyword, in the above
example "+explain". Several such keywords may be defined, each
separated by commas. Note that the case of letters in the keywords
Location of message files
It is possible to specify alternative locations for message files so
that alternatives are selected according to the application being run
The location may be specified using configuration files in a similar
fashion to the search for options, except that the search runs the
The search is in the following order:
If a configuration file in the current directory specifies a
location for the message file, by means of an assignment to the
relevant variable (for most shell-based commands this is
"SPRESTCONF"), then this file is taken.
Environment variables in the form $ABC and users' home directories
in the form "~"user are appropriately expanded. The sequence $0 is
replaced by the name of the program being invoked. (This process
may run recursively up to a level of 10).
If the relevant environment variable (for most shell-based commands
this is "SPRESTCONF") specifies a location, then this is taken.
A configuration file in the home directory may specify a location
for the message file.
If none of the above specify a replacment message file then the
default location is taken.
If a file is specified but does not exist, then this is a fatal error.
However there is an additional step to assist the user to set up some
alternative files with a default name.
Should the file not exist, then the search falls back to a name
generated by taking the last part of the default file name (for example
rest.conf) and substituting this for the last part of the file name
For example if the normal message file for the command were
and the user had specified in a configuration file
then if he or she were to run, say, gspl-pr, then the file
would be searched for. If this did not exist, then a search would be
Path to locate message files
The above search path may be modified using the environment variable
"GS_HELPPATH". The interpretation is very similar to the description
above for "GS_CONFIGPATH", except that "-" fields are ignored.
The default value of "GS_HELPPATH" is ".:!:~$LIBRARY" giving the
interpretation described above. Note that this is in the opposite order
~/.gnuspool configuration file (home directory)
.gnuspool configuration file (current directory)
Path to search for options in.
Path to search for location of message files in.
Copyright (c) 2009 Free Software Foundation, Inc. This is free
software. You may redistribute copies of it under the terms of the GNU
General Public License <http://www.gnu.org/licenses/gpl.html>. There
is NO WARRANTY, to the extent permitted by law.
John M Collins, Xi Software Ltd.