SAS 9.4 Macro Language: Reference, Fourth Edition, 4th Edition

The macro CHECK2 produces the same result as the macro CHECK:

data flights;

set schedule;

totmiles=sum(of miles1-miles20);

proc print;

var flightid totmiles;

run;

However, in the macro CHECK2, the value assigned to VAL is simply the name PGM,

not the value of PGM. The macro processor resolves &&&VAL into &PGM and then

into the SAS statements contained in the macro variable PGM. Thus, the long value is

stored only once.

Writing Portable Macros

Using Portable SAS Language Functions with %SYSFUNC

If your code runs in two different environments, you have essentially doubled the worth

of your development effort. But portable applications require some planning ahead. For

more details about any host-specific feature of SAS, see the SAS documentation for your

host environment.

You can use the %SYSFUNC macro function to access SAS language functions to

perform most host-specific operations, such as opening or deleting a file. For more

information, see “%SYSFUNC and %QSYSFUNC Functions” on page 277.

Using %SYSFUNC to access portable SAS language functions can save you a lot of

macro coding (and is therefore not only portable but also more efficient). The following

table lists some common host-specific tasks and the functions that perform those tasks.

Table 11.1 Portable SAS Language Functions and Their Uses

Task

SAS Language

Function or

Functions

Assign and verify existence of fileref and physical file FILENAME,

FILEREF,

PATHNAME

Open a file FOPEN, MOPEN

Verify existence of a file FEXIST, FILEEXIST

Get information about a file FINFO,

FOPTNAME,

FOPTNUM

Write data to a file FAPPEND, FWRITE

Read from a file FPOINT, FREAD,

FREWIND, FRLEN

148 Chapter 11 • Writing Efficient and Portable Macros

Task

SAS Language

Function or

Functions

Close a file FCLOSE

Delete a file FDELETE

Open a directory DOPEN

Return information about a directory DINFO, DNUM,

DOPTNAME,

DOPTNUM, DREAD

Close a directory DCLOSE

Read a host-specific option GETOPTION

Interact with the File Data Buffer (FDB) FCOL, FGET,

FNOTE, FPOS,

FPUT, FSEP

Assign and verify librefs LIBNAME, LIBREF,

PATHNAME

Get information about executed host environment commands SYSRC

Note: Of course, you can also use other functions, such as ABS, MAX, and

TRANWRD, with %SYSFUNC. A few SAS language functions are not available

with %SYSFUNC. For more information, see “%SYSFUNC and %QSYSFUNC

Functions” on page 277.

Example Using %SYSFUNC

The following program deletes the file identified by the fileref MyFile:

%macro testfile(filrf);

%let

rc=%sysfunc(filename(filrf,physical-filename));

%if &rc = 0 and %sysfunc(fexist(&filrf)) %then

%let rc=%sysfunc(fdelete(&filrf));

%let rc=%sysfunc(filename(filrf));

%mend testfile;

%testfile(myfile)

Using Automatic Variables with Host-Specific Values

Macro Variables by Task

The automatic macro variables are available under all host environments, but the values

are determined by each host. The following table lists the macro variables by task. The

Writing Portable Macros 149

“Type” column tells you if the variable can be changed (Read and Write) or can be

inspected (Read Only).

Table 11.2 Automatic Macro Variables with Host-Specific Results

Task

Automatic Macro

Variable Type

List the name of the current graphics device

on DEVICE=.

SYSDEVIC Read and write

List of the mode of execution (values are

FORE or BACK). Some host environments

allow only one mode, FORE.

SYSENV Read-only

List the name of the currently executing

batch job, user ID, or process. For example,

on UNIX, SYSJOBID is the PID.

SYSJOBID Read-only

List the last return code generated by your

host environment, based on commands

executed using the X statement in open code.

The X command in the SAS windowing

environment, or the %SYSEXEC (or %TSO

or %CMS) macro statements.

The default value is 0.

SYSRC Read and write

List the abbreviation of the host environment

that you are using.

SYSSCP Read-only

List a more detailed abbreviation of the host

environment that you are using.

SYSSCPL Read-only

Retrieve a character string that was passed to

SAS by the SYSPARM= system option.

SYSPARM Read and write

Time zone name based on TIMEZONE

option.

SYSTIMEZONE Read-only

Time zone ID based on TIMEZONE option. SYSTIMEZONEIDENT Read-only

Current time zone offset based on

TIMEZONE option.

SYSTIMEZONEOFFSET Read-only

Examples Using SYSSCP and SYSSCPL

The macro DELFILE uses the value of SYSSCP to determine the platform that is

running SAS and deletes a TMP file. FILEREF is a macro parameter that contains a

filename. Because the filename is host-specific, making it a macro parameter enables the

macro to use whatever filename syntax is necessary for the host environment.

%macro delfile(fileref);

/* Unix */

%if &sysscp=HP 800 or &sysscp=HP 300 %then %do;

X “rm &fileref..TMP”;

%end;

150 Chapter 11 • Writing Efficient and Portable Macros