.ig >>
<STYLE TYPE="text/css">
<!--
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</STYLE>
<title>ploticus: ploticus scripts</title>
<body bgcolor=D0D0EE vlink=0000FF>
<br>
<br>
<center>
<table cellpadding=2 bgcolor=FFFFFF width=550 ><tr>
<td>
  <table cellpadding=2 width=550><tr>
  <td><br><h2>Ploticus scripts</h2></td>
  <td align=right>
  <small>
  <a href="../doc/Welcome.html"><img src="../doc/ploticus.gif" border=0></a><br>
  <a href="../doc/Welcome.html">Welcome</a> &nbsp; &nbsp;
  <a href="../gallery/index.html">Gallery</a> &nbsp; &nbsp;
  <a href="../doc/Contents.html">Handbook</a> 
  <td></tr></table>
</td></tr>
<td>
<br>
<br>
.>>

.TH Ploticus_scripts PL "06-SEP-2001   PL www.sgpr.net"

.SH DESCRIPTION
.LP
Ploticus is controlled by scripts that a 
user creates in a text editor.
The scripts can also be created by other programs.

.ig >>
<br><br><br>
.>>

.SH EXAMPLE
Here is an example of a ploticus script:
.nf
.ft C
.ig >>
<br><img src="../gallery/sa1.gif"><br>
.>>
\0#proc areadef
\0  rectangle: 1 1 4 2
\0  xrange: 0 5
\0  yrange: 0 100
\0
\0#proc xaxis:
\0  stubs: text
\0	Africa
\0	Americas
\0	Asia
\0	Europe,\\nAustralia,\\n\& Pacific
\0
\0#proc yaxis
\0  label: Growth Rate
\0  stubs: inc 20
\0  minortics: yes
\0  minorticinc: 5
\0
\0#proc getdata
\0  data: 76 
\0	54 
\0	60 
\0	59
\0
\0#proc bars
\0  lenfield: 1
\0  color: teal
\0  barwidth: 0.2
\0
.ft R
.fi

.LP
As you can see, this is not low-level 3GL-style code.  It is a sort of
hybrid; plotting actions (#procs) are specified in procedural order,
but within each #proc the language is goal-driven (4GL).  Thus, traditional
procedural programming skills are not required.
.LP
The above Ploticus script invokes a number of procedures (procs).
First,
\fBproc areadef\fR to set up a plotting area, then
\fBproc xaxis\fR and \fByaxis\fR to render the axes.
Then \fBproc getdata\fR is invoked to define some data, 
and then finally \fBproc bars\fR is invoked to produce a bar graph.
.LP
For each proc, the user may specify a various attributes or options.
Attributes that are not specified use a default when possible.
In the above example, the user has invoked \fCproc areadef\fR
and specified values for these attributes: \fCrectangle\fR, \fCxrange\fR,
and \fCyrange\fR.  
All of the procs, as well as the names, types, and acceptable 
values for all attributes, are described in the 
.ig >>
<a href="../doc/Contents.html">
.>>
\0ploticus handbook.
.ig >>
</a>
.>>

.ig >>
<br><br><br>
.>>
.ig >>
<a name=procs></a>
.>>

.SH PROCEDURES (PROCS) AND ATTRIBUTES
.LP
\fBProcedures (procs)\fR are always invoked using this construct: \fC#proc \fIprocname\fR.
The word \fC#proc\fR indicates the start of a procedure specification block;
the other word is the name of a procedure (case insensitive).
.LP
\fBAttributes\fR within a procedure may be specified in any order.  
A colon (\fB:\fR) may be used after an attribute
name or a procedure name (however it is not required).  
All proc names and attribute names are case-insensitive.  
Attributes that are multiline text type
are terminated by a blank line.
.LP
The following script directives are used by ploticus in executing procedures:


.SH #proc
.IP
This directive signals the beginning of a 
.ig >>
<a href="Contents.html#scripts">
.>>
\0ploticus procedure
.ig >>
</a>
.>>
(proc).  
.br
Example: \fC#proc bars\fR

.SH #proc endproc
.IP
This signals the end of a ploticus procedure (proc).
Only required in 
.ig >>
<a href="endproc.html">
.>>
\0certain cases.
.ig >>
</a>
.>>
.br
Example: \fC#proc endproc\fR


.SH #procdef
.IP
This directive is used similarly to #proc, but it does not
execute the procedure; it only defines it so that it may
be \fB#clone\fRd later.
The procedure should contain a \fC#saveas\fR.
.br
Example: \fC#procdef bars\fR

.SH #saveas
.IP
Makes the current proc available to be \fBclone\fRd by procs 
encountered later in the script, and assigns it an identifier
(B1 in the example below).
A gallery example that uses \fBsaveas\fR and \fBclone\fR is
.ig >>
<a href="../gallery/rangebar1.htm">
.>>
\0rangebar1
.ig >>
</a>
.>>
\0.  May be used anywhere within the proc.
.br
Example: \fC#saveas B1\fR

.SH #clone
.IP
\fBclone\fR is used like an attribute.
Inherits all attribute values from a previously \fBsave\fRd proc. 
May be used anywhere within the proc.
Attributes may be overridden locally as desired.
.br
Example: \fC#clone B1\fR

.LP
Other general purpose directives are described below.

.ig >>
<a name=syntax></a>
.>>
.ig >>
<br><br><br>
.>>

.SH SYNTAX AND VARIABLES


Any line where the first non-whitespace content is \fC//\fR is a \fBcomment\fR
and is ignored.  Comments must be alone on the line.
Any line where the first non-whitespace content begins with \fB#\fR is a
.ig >>
<a href="#directives">
.>>
\0directive
.ig >>
</a>
.>>
(an operator that does something).
Everything else is generally HTML and is passed through transparently, except for 
evaluation of \fBvariables\fR, and possible processing of certain
.ig >>
<a href="inlinecodes.html">
.>>
\0inline formatting codes
.ig >>
</a>
.>>
\0.
.LP
Double quotes (\fB"\fR) may be used to enclose character strings in
.ig >>
<a href="set.html">
.>>
\0set
.ig >>
</a>
.>>
,
.ig >>
<a href="setifnotgiven.html">
.>>
\0setifnotgiven
.ig >>
</a>
.>>
,
.ig >>
<a href="if.html">
.>>
\0if, elseif
.ig >>
</a>
.>>
and 
.ig >>
<a href="call.html">
.>>
\0call
.ig >>
</a>
.>>
\0.
Everywhere else, quotes have no special syntactical meaning
and may be used freely without any special treatment.
It is safe to use \fBTAB\fRs to indent lines of code and in transparent
output; other uses (such as embedding \fBTAB\fR in variable contents) should be avoided.
.LP
Scripts
can set and reference \fBvariables\fR.
Variable names must begin with a letter and may contain 
letters, digits, underscore (_) and period (.).
Names are case-sensitive.
Maximum length of a variable name is 38 characters.
Variables may hold numbers, alphanumerics, or single-line text strings, 
up to a maximum content length of 250 characters.  
Variables cannot hold more than one line of text.
All data, including numbers, are stored as characters.
Where a variable is to be evaluated,
it should be prefaced with an at-sign (\fB@\fR).
In order to print an at-sign a double at sign (@) may be used.
When setting or identifying a variable, the at-sign should not be used.
Examples:
.nf
	\0Hello, my name is @NAME
	\0#shell cat data | recsel "@@3 = res"
	\0#set NAME = "Harvey Smith"
.fi
An attempt to evaluate a variable that has never been assigned a value
will result in cancellation of the evaluation (the variable name will be
passed through transparently) and no error condition will be raised.
Several 
.ig >>
<a href="variables.html">
.>>
\0reserved variables
.ig >>
</a>
.>>
exist.  All variables are global in scope.

.ig >>
<a name=functions>
.>>
.ig >>
<br><br><br>
.>>
.SH FUNCTIONS
Functions may be used to assign a value to a variable (
.ig >>
<a href="#set">
.>>
\0set
.ig >>
</a>
.>>
, 
.ig >>
<a href="#setifnotgiven">
.>>
\0setifnotgiven
.ig >>
</a>
.>>
), and in 
.ig >>
<a href="#if">
.>>
\0if
.ig >>
</a>
.>>
statements.  Function names always begin with a dollar sign ($), for
example: \fC$strlen( "hello world" )\fR.
For descriptions of the
available functions, see the
.ig >>
<a href="functions.html">
.>>
\0functions man page
.ig >>
</a>
.>>
\0.

There are functions for
.ig >>
<a href="functions.html#ploticus">
.>>
\0plotting
.ig >>
</a>
.>>
,
.ig >>
<a href="functions.html#arithmetic">
.>>
\0arithmetic
.ig >>
</a>
.>>
,
.ig >>
<a href="functions.html#strings">
.>>
\0strings
.ig >>
</a>
.>>
,
.ig >>
<a href="functions.html#commalists">
.>>
\0commalists
.ig >>
</a>
.>>
,
.ig >>
<a href="shell.html">
.>>
\0shell
.ig >>
</a>
.>>
,
.ig >>
<a href="sql.html">
.>>
\0sql
.ig >>
</a>
.>>
,
.ig >>
<a href="functions.html#dates">
.>>
\0dates
.ig >>
</a>
.>>
,
.ig >>
<a href="functions.html#times">
.>>
\0times
.ig >>
</a>
.>>
, and 
.ig >>
<a href="functions.html#misc">
.>>
\0other
.ig >>
</a>
.>>
\0.
Custom functions may be implemented in \fCcustom.c\fR.



.ig >>
<a name=directives></a>
.>>
.ig >>
<br><br><br>
.>>

.SH MORE DIRECTIVES
Directives are operators that do something, such as \fC#set\fR.
Directives always begin with a pound sign (\fB#\fR), and usually occupy one line alone
(a few of the directives, such as
.ig >>
<a href="#shell">
.>>
\0shell
.ig >>
</a>
.>>
and
.ig >>
<a href="#sql">
.>>
\0sql
.ig >>
</a>
.>>
can be multiline constructs).
Individual "words" or tokens within a directive must be separated by white space.
Directives may be indented using spaces or tabs.
.LP
Descriptions of the flow-of-control directives follow:


.ig >>
<br><br><br>
.>>

.ig >>
<a name=set></a>
.>>

.SH #set
.RS
.LP
\fC#set  \fIvariable\fC  =  \fInumeric\fR
.br
\fC#set  \fIvariable\fC  =  "\fItext\fC"\fR
.br
\fC#set  \fIvariable\fC  =  $\fIfunction\fR
.LP
Assigns a value to a \fIvariable\fR.
The value may be a constant or a variable, and
may be a numeric, alphanumeric/text, or 
.ig >>
<a href="functions.html">
.>>
\0function
.ig >>
</a>
.>>
result.
Alphanumeric/text literals should be enclosed in double quotes (the
closing quote may be omitted if desired).
The \fIvariable\fR may be a simple standalone variable or a field
in a 
.ig >>
<a href="fdf.html">
.>>
\0logical record
.ig >>
</a>
.>>
\0.
Whitespace must follow the \fC#set\fR, the \fIvariable\fR, and the equals sign (=).
Multiple alphanumeric variables or constants may be used on the right hand side, resulting
in concatenation, however they must be separated by whitespace.
Other directives that can set variables include:
.ig >>
<a href="setifnotgiven.html">
.>>
\0setifnotgiven
.ig >>
</a>
.>>
,
.ig >>
<a href="shell.html">
.>>
\0shell
.ig >>
</a>
.>>
,
.ig >>
<a href="sql.html">
.>>
\0sql
.ig >>
</a>
.>>
,
\0.
Examples:
.LP
.nf
\0#set COUNT = 0
\0#set LABEL = "My favorite martian"
\0#set LABEL = "My favorite martian    
\0#set LABEL = @A @B        
\0#set LABEL = @A ", " @B        
\0#set TODAY = $todaysdate()
\0#set TOTAL = $arith(@X+@Y+@Z)     
.fi
.RE

.ig >>
<a name=setifnotgiven></a>
.>>

.SH #setifnotgiven
.RS
.LP
\fC#setifnotgiven  \fIvariable\fC  =  \fIvalue\fR
.LP
Similar to
.ig >>
<a href="#set">
.>>
\0set
.ig >>
</a>
.>>
except that it takes action only if \fIvariable\fR is empty ("") or 
has never been assigned a value.  Useful for setting default values in forms.
.br
Example: \fC#setifnotgiven CUTOFF = 0.5\fR
.RE

.ig >>
<a name=call></a>
.>>

.SH #call
.RS
.LP
\fC#call  \fIfunction\fR
.LP
Invoke a \fI
.ig >>
<a href="functions.html">
.>>
\0function
.ig >>
</a>
.>>
\fR without retaining its return value.  
.br
Example: \fC#call $setdatefmt( "yyyy-mmm-dd" )\fR
.RE

.ig >>
<a name=if></a>
.>>

.SH #if  
.RS
Alter execution flow of control based on \fI
.ig >>
<a href="condex.html">
.>>
\0conditional expressions
.ig >>
</a>
.>>
\fR. 
\fBif\fR and \fBendif\fR are required.  
\fBelseif\fR and \fBelse\fR are optional.
An example of an #if construct:
.LP
.nf
\0#if @mode = A
    <h4>Mode is A</h4>
\0#elseif @mode = B
    <h4>Mode is B</h4>
\0#else
    <h4>Mode not given</h4>
\0#endif
.fi
.LP
Some examples of conditional expressions:
.LP
.nf
\0#if @tag = TOTAL
\0#if @meas > 0.0 && @meas < 8.5
\0#if @name = ""
\0#if @type like "west*" || @type = "bl*"
\0#if $arith(@A+@B) > 10
.fi
.RE
.LP

.ig >>
<a name=for></a>
.>>

.SH #for
.RS
\fC#for  \fIvar\fC  in  \fIcommalist\fR
.br
\0..
.br
\fC#endloop\fR
.br
.br
\fC#for  \fIvar\fC  across  \fImultirow-response\fR
.br
\0..
.br
\fC#endloop\fR
.LP
Loop the flow of control, iterating across members of 
.ig >>
<a href="commalist.html">
.>>
\0commalist
.ig >>
</a>
.>>
\fIvar\fR will be set to each member from first to last.
If \fIcommalist\fR
or \fImultirow-response\fR
is empty, the loop body will not be executed.
This example illustrates the construct, without doing
anything useful:
.LP
.nf
\0#set COLORLIST = "red,blue,green,yellow
\0#for  COLOR  in  @COLORLIST
\0    #if  @COLOR  =  green
\0        #break
\0    #elseif  @COLOR  =  blue
\0        #continue
\0    #endif
\0#endloop
.fi
.RE

.ig >>
<a name=while></a>
.>>

.SH #while
.RS
\fC#while\fC  \fIconditional expression\fR
.br
\0..(loop body)..
.br
\fC#endloop\fR
.LP
Loop the flow of control while 
.ig >>
<a href="condex.html">
.>>
\0conditional
.ig >>
</a>
.>>
is true.
If \fIconditional expression\fR is initially false, the loop body
will not be executed at all.
The following example loops until I > 10:
.LP
.nf
\0#set I = 0
\0#while @I <= 10
\0  #set I = $arith(@I+1)
\0#endloop
.fi
.RE

.ig >>
<a name=loop></a>
.>>

.SH #loop
.RS
.LP
\fC#loop\fR
.br
\0..
.br
\fC#endloop\fR
.LP
Loop the flow of control.  A 
.ig >>
<a href="#break">
.>>
\0break
.ig >>
</a>
.>>
statement must be used to terminate the loop.
The following example loops until I > 10:
.LP
.nf
\0#set I = 0
\0#loop
\0   #set I = $arith(@I+1)
\0   #if @I > 10
\0       #break
\0   #endif
\0#endloop
.fi
.RE

.ig >>
<a name=break></a>
.>>

.SH #break
.RS
Terminate the iteration of the most recently invoked
.ig >>
<a href="for.html">
.>>
\0for 
.ig >>
</a>
.>>
loop,
.ig >>
<a href="while.html">
.>>
\0while 
.ig >>
</a>
.>>
loop, or plain
.ig >>
<a href="loop.html">
.>>
\0loop
.ig >>
</a>
.>>
\0.  Script execution resumes at the statement immediately following
the corresponding \fBendloop\fR.
There are restrictions if used within an 
.ig >>
<a href="include.html">
.>>
\0included
.ig >>
</a>
.>>
file.
.RE

.ig >>
<a name=continue></a>
.>>

.SH #continue
.RS
Proceed directly to the next
iteration of the most recently invoked
.ig >>
<a href="for.html">
.>>
\0for 
.ig >>
</a>
.>>
loop,
.ig >>
<a href="while.html">
.>>
\0while
.ig >>
</a>
.>>
loop, or plain
.ig >>
<a href="loop.html">
.>>
\0loop
.ig >>
</a>
.>>
\0.  
There are restrictions if used within an 
.ig >>
<a href="include.html">
.>>
\0included
.ig >>
</a>
.>>
file.
.RE

.ig >>
<a name=exit></a>
.>>

.SH #exit
.RS
Terminate execution immediately.  Example:
.LP
.nf
\0#if @_DEBUG = 1
\0    #exit
\0#endif
.fi
.RE

.ig >>
<a name=include></a>
.>>

.SH #include
.RS
\fC#include  \fIfile\fR
.LP
Include script code from a \fIfile\fR.
\fIfile\fR is relative to 
\fBscriptdir\fR as defined in the
.ig >>
<a href="config.html">
.>>
\0project config file
.ig >>
</a>
.>>
\0.
Includes may be nested.
\fBinclude\fRd code is interpreted in the same manner as ordinary code.
However, 
.ig >>
<a href="break.html">
.>>
\0break
.ig >>
</a>
.>>
and
.ig >>
<a href="continue.html">
.>>
\0continue
.ig >>
</a>
.>>
may be used only if the corresponding loop / #endloop is also within
the included file.
.ig >>
<a href="return.html">
.>>
\0return
.ig >>
</a>
.>>
may be used to immediately exit the included file and resume execution
in the including file.
.br
Example: \fC#include projectheader\fR
.RE

.ig >>
<a name=cat></a>
.>>
.SH #cat
.RS
\fC#cat  \fIfile1\fR [..\fIfileN\fR]
.LP
Copy the contents of \fIfile\fRs to the standard output.
No processing or interpretation is done to the contents.
Suitable for text files or binary files.
.br
Example: \fC#cat /home/scg/img/banner.gif\fR
.RE

.ig >>
<a name=return></a>
.>>

.SH #return
.RS
Terminate execution of an
.ig >>
<a href="include.html">
.>>
\0included
.ig >>
</a>
.>>
file immediately.
Execution is resumed at the statement immediately following
the \fBinclude\fR.
.RE



.ig >>
<a name=write></a>
.>>

.SH #write
.RS
\fC#write  \fIfile\fC  [\fIfilemode\fR]
.br
\0..\fItext\fR..
.br
\fC#endwrite\fR \fC[noclose]\fR
.LP
Write \fItext\fR to \fIfile\fR.
\fIfile\fR may be a file name or \fCstderr\fR or \fCstdout\fR.
\fIfilemode\fR is either \fCw\fR to create, or \fCa\fR to append.
Within the construct, other directives, such as
.ig >>
<a href="if.html">
.>>
\0#if
.ig >>
</a>
.>>
,
.ig >>
<a href="for.html">
.>>
\0#for
.ig >>
</a>
.>>
,
.ig >>
<a href="include.html">
.>>
\0#include
.ig >>
</a>
.>>
and so on may be freely used.
If \fCstdout\fR or \fCstderr\fR are used, the \fIfilemode\fR is ignored
and the \fCnoclose\fR option should be given with #endwrite.
.LP
The following example, if used in header code included by 
all pages in a cgipal project, would log page hits with date, 
time, name of page, and the HTTP info.
.LP
.nf
\0#set RH = $getenv(HTTP_REMOTE_HOST)
\0#set RF = $getenv(HTTP_REFERER)
\0#call $setdatefmt(yyyy/mmm/dd)
\0#set DATE = $todaysdate()
\0#set TIME = $time()
\0#write /tmp/mylog a
\0@DATE @TIME @_PAGE @RH @RF
\0#endwrite
.fi
.RE

.ig >>
<a name=control></a>
.>>
.SH #control
.RS
\fC#control  \fIattribute\fC   \fIvalue\fR
.LP
Set various operational modes.
\fIattribute\fR may be one of:
\fCallowinlinecodes\fR,
\fCdbquote\fR,
\fChtmlqhmode\fR,
\fClistsep\fR,
\fCevalvars\fR ,
\fCsuppressdll\fR,
or \fCdot_in_varnames\fR.

.LP
.ig >>
<a href="control.html">
.>>
\0Full description of #control directive
.ig >>
</a>
.>>
.RE




.ig >>
<br><br><br>
.>>

.ig >>
<a name=#interaction></a>
.>>
.SH INTERACTION WITH DATABASES AND SHELL

.ig >>
<a name=sql></a>
.>>

.SH #sql
.RS
\fC#sql [\fIoption\fC]  \fIsql command\fC  [#endsql]\fR
.LP
This directive allows SQL code to be embedded in scripts, and
submits the embedded SQL code to your database.
The \fIsql command\fR may use a single line construct or a
multi-line construct.  \fC#endsql\fR must be used to terminate
a multi-line construct.
For SQL SELECT commands an \fIoption\fR may be given; available
options are \fC#processrows\fR (the default), \fC#load\fR, 
\fC#dump\fR, \fC#dumptab\fR, \fC#dumphtml\fR, and \fC#dumpsilent\fR.
.LP
Two separate SQL database connections are available.  For connection 1,
use \fB#sql\fR; for connection 2, use \fB#sql2\fR instead of \fB#sql\fR
(all other syntax is the same).
.LP
.ig >>
<a href="sql.html">
.>>
\0More on #sql and interacting with databases
.ig >>
</a>
.>>
.RE

.ig >>
<a name=shell></a>
.>>

.SH #shell
.RS
\fC#shell  \fIoption\fC  \fIcommand\fC  [#endshell]
.LP
Execute the given shell \fIcommand\fR, and optionally display or 
capture the results.
The \fIcommand\fR may use a single line construct or a
multi-line construct.  \fC#endshell\fR must be used to terminate
a multi-line construct.
An \fIoption\fR may be given; available
options are \fC#load\fR, \fC#processrows\fR, 
\fC#dump\fR (the default), \fC#dumptab\fR, \fC#dumphtml\fR, and \fC#dumpsilent\fR.
.LP
.ig >>
<a href="shell.html">
.>>
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