Putting out a block of text: $onput, $offput, $onputs, $onputv

Sometimes one needs to put out several lines of text just for appearances sake.  In such a case using conventional puts one would have syntax like the following (putex12.gms)

Put 'Line 1 of text' /;

Put 'Line 2 of text' //;

Put 'Line 3 of text' /;

Put 'Line 4 of text' /;

One may use the commands $onput and $offput as an alternative

$onput

Line 1 of text

Line 2 of text

Line 3 of text

Line 4 of text

$offput

Yielding idenetical put files.  In this case the text block is begun with $onput and ended with $offput.

There is also a variant, 2, that uses substitutable parameters (Parameter substitution is discussed in the Conditional Compilation chapter).  Namely $onputs will cause all parameter statements in it (those enclosed in % signs) to be replaced with any defined GAMS calling parameters of control variables. $onputv suppresses any substitution.  For example the sequence (putex12.gms)

$setglobal it "from $onputs"

$onputs

substitution

Line 1 of text "%it%"

Line 2 of text %it%

Line 3 of text %it%

Line 4 of text %it%

$offput

Generates the output

substitution

Line 1 of text "from $onputs"

Line 2 of text from $onputs

Line 3 of text from $onputs

Line 4 of text from $onputs

While (putex12.gms)

$setglobal it "from $onputs"

$onputv

No substitution

Line 1 of text "%it%"

Line 2 of text %it%

Line 3 of text %it%

Line 4 of text %it%

$offput

Generates

No substitution

Line 1 of text "%it%"

Line 2 of text %it%

Line 3 of text %it%

Line 4 of text %it%