Note: You can also perform the inverse of a macro quoting function — that is, remove
the tokenization provided by macro quoting functions. For an example of when the
%UNQUOTE function is useful, see “Unquoting Text” on page 97.
%STR and %NRSTR Functions
Using %STR and %NRSTR Functions
If a special character or mnemonic affects how the macro processor constructs macro
program statements, you must mask the item during macro compilation (or during the
compilation of a macro program statement in open code) by using either the %STR or
%NRSTR macro quoting functions.
These macro quoting functions mask the following special characters and mnemonics:
Table 7.3 Special Characters Masked by the %STR and %NRSTR Functions
blank ) = NE
; ( | LE
¬ + # LT
^ — AND GE
~ * OR GT
, (comma) / NOT
' < IN
“ > EQ
In addition to these special characters and mnemonics, %NRSTR masks & and %.
Note: If an unmatched single or double quotation mark or an open or close parenthesis
is used with %STR or %NRSTR, these characters must be preceded by a percent
sign (%).
When you use %STR or %NRSTR, the macro processor does not receive these functions
and their arguments when it executes a macro. It receives only the results of these
functions because these functions work when a macro compiles. By the time the macro
executes, the string is already masked by a macro quoting function. Therefore, %STR
and %NRSTR are useful for masking strings that are constants, such as sections of SAS
code. In particular, %NRSTR is a good choice for masking strings that contain % and &
signs. However, these functions are not so useful for masking strings that contain
references to macro variables because it is possible that the macro variable could resolve
to a value not quotable by %STR or %NRSTR. For example, the string could contain an
unmarked, unmatched open parenthesis.
%STR and %NRSTR Functions 87
Using Unmatched Quotation Marks and Parentheses with %STR and
%NRSTR
If the argument to %STR or %NRSTR contains an unmatched single or double quotation
mark or an unmatched open or close parenthesis, precede each of these characters with a
% sign. The following table shows some examples of this technique.
Table 7.4 Examples of Marking Unmatched Quotation Marks and Parentheses with %STR
and %NRSTR
Notation Description Example
Quoted Value
Stored
%' unmatched single
quotation mark
%let myvar=
%str(a%');
a'
%" unmatched double
quotation mark
%let myvar=
%str(title
%”first);
title “first
%( unmatched open
parenthesis
%let myvar=
%str (log
%(12);
log(12
%) unmatched close
parenthesis
%let myvar=
%str (345%));
345)
Using % Signs with %STR
In general, if you want to mask a % sign with a macro quoting function at compilation,
use %NRSTR. There is one case where you can use %STR to mask a % sign: when the
% sign does not have any text following it that could be construed by the macro
processor as a macro name. The % sign must be marked by another % sign. Here are
some examples.
Table 7.5 Examples of Masking % Signs with %STR
Notation Description Example
Quoted Value
Stored
'%' % sign before a matched
single quotation mark
%let myvar=
%str('%');
'%'
%%%' % sign before an unmatched
single quotation mark
%let myvar=
%str(%%%');
%'
""%% % sign after a matched
double quotation mark
%let myvar=
%str(""%%);
""%
88 Chapter 7 • Macro Quoting
Notation Description Example
Quoted Value
Stored
%%%% two % signs in a row
%let myvar=
%str(%%%%);
%%
Note: If a macro variable ends with a % and at resolution is followed immediately by a
non-blank character followed by another macro variable, the second macro variable
might print twice. This can be avoided by using the %NRSTR function along with
two percent signs. For example, change the original syntax
%let val=abc%;
to this syntax
%let val=%nrstr(abc%%);
Examples Using %STR
The %STR function in the following %LET statement prevents the semicolon after
PROC PRINT from being interpreted as the ending semicolon for the %LET statement:
%let printit=%str(proc print; run;);
As a more complex example, the macro KEEPIT1 shows how the %STR function works
in a macro definition:
%macro keepit1(size);
%if &size=big %then %put %str(keep city _numeric_;);
%else %put %str(keep city;);
%mend keepit1;
Call the macro as follows:
%keepit1(big)
This code produces the following statement:
keep city _numeric_;
When you use the %STR function in the %IF-%THEN statement, the macro processor
interprets the first semicolon after the word %THEN as text. The second semicolon ends
the %THEN statement, and the %ELSE statement immediately follows the %THEN
statement. Thus, the macro processor compiles the statements as you intended. However,
if you omit the %STR function, the macro processor interprets the first semicolon after
the word %THEN as the end of the %THEN clause. The next semicolon as constant text.
Because only a %THEN clause can precede a %ELSE clause, the semicolon as constant
text causes the macro processor to issue an error message and not compile the macro.
In the %ELSE statement, the %STR function causes the macro processor to treat the first
semicolon in the statement as text and the second one as the end of the %ELSE clause.
Therefore, the semicolon that ends the KEEP statement is part of the conditional
execution. If you omit the %STR function, the first semicolon ends the %ELSE clause
and the second semicolon is outside the conditional execution. It is generated as text
each time the macro executes. (In this example, the placement of the semicolon does not
affect the SAS code.) Again, using %STR causes the macro KEEPIT1 to compile as you
intended.
Here is an example that uses %STR to mask a string that contains an unmatched single
quotation mark. Note the use of the % sign before the quotation mark:
%STR and %NRSTR Functions 89
%let innocent=%str(I didn%'t do it!);
Examples Using %NRSTR
Suppose you want the name (not the value) of a macro variable to be printed by the
%PUT statement. To do so, you must use the %NRSTR function to mask the & and
prevent the resolution of the macro variable, as in the following example:
%macro example;
%local myvar;
%let myvar=abc;
%put %nrstr(The string &myvar appears in log output,);
%put instead of the variable value.;
%mend example;
%example
This code writes the following text to the SAS log:
The string &myvar appears in log output,
instead of the variable value.
If you did not use the %NRSTR function or if you used %STR, the following undesired
output would appear in the SAS log:
The string abc appears in log output,
instead of the variable value.
The %NRSTR function prevents the & from triggering macro variable resolution.
The %NRSTR function is also useful when the macro definition contains patterns that
the macro processor would ordinarily recognize as macro variable references, as in the
following program:
%macro credits(d=%nrstr(Mary&Stacy&Joan Ltd.));
footnote "Designed by &d";
%mend credits;
Using %NRSTR causes the macro processor to treat &STACY and &JOAN simply as
part of the text in the value of D; the macro processor does not issue warning messages
for unresolvable macro variable references. Suppose you invoke the macro CREDITS
with the default value of D, as follows:
%credits()
Submitting this program generates the following FOOTNOTE statement:
footnote "Designed by Mary&Stacy&Joan Ltd.";
If you omit the %NRSTR function, the macro processor attempts to resolve the
references &STACY and &JOAN as part of the resolution of &D in the FOOTNOTE
statement. The macro processor issues these warning messages (assuming the SERROR
system option, described in “System Options for Macros” on page 353 is active) because
no such macro variables exist:
WARNING: Apparent symbolic reference STACY not resolved.
WARNING: Apparent symbolic reference JOAN not resolved.
90 Chapter 7 • Macro Quoting
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