/*作用：将数据集中字符型变量长度改成最大长度加10*/
宏的编译，宏存储
OPTIONS NOCENTER LS=MAX PS=MAX SASMSTORE=SASUSER MSTORED MAUTOSOURCE;
%MACRO M_CHANGE_LENGTH(IN_TABLE,OUT_TABLE)/STORE;
PROC CONTENTS DATA=&IN_TABLE OUT=B NOPRINT;
RUN;
/*提取字符型变量*/
DATA B(KEEP=NAME);
SET B;
IF TYPE=2;
RUN;
/*求字符型变量个数*/
DATA _NULL_;
SET B NOBS=NOBS;
CALL SYMPUTX('CHAR_NUM',NOBS);
STOP;
RUN;
/*依次求字符型变量的长度*/
%DO I=1 %TO &CHAR_NUM;
DATA _NULL_;
SET B(FIRSTOBS=&I OBS=&I);
CALL SYMPUTX('VAR_NAME',NAME);
STOP;
RUN;
%IF &I=1 %THEN %DO;
DATA TEMP(KEEP=X_&I);
SET &IN_TABLE;
X_&I=LENGTH(STRIP(&VAR_NAME.));
RUN;
%END;
%ELSE %DO;
DATA APPEND(KEEP=X_&I);
SET &IN_TABLE;
X_&I=LENGTH(STRIP(&VAR_NAME.));
RUN;
DATA TEMP;
SET TEMP;
SET APPEND;
RUN;
%END;
%END;
/*求出字符串长度的最大值*/
PROC MEANS DATA=TEMP MAX;
VAR X_1-X_&CHAR_NUM;
OUTPUT OUT=TEMP1;
RUN;
DATA TEMP1(DROP=_TYPE_ _FREQ_);
SET TEMP1;
IF _STAT_='MAX';
RUN;
PROC TRANSPOSE DATA=TEMP1 OUT=TEMP2;
VAR X_1-X_&CHAR_NUM;
RUN;
DATA TEMP2(RENAME=(COL1=OLD_LEN));
LENGTH DEF_LEN $200.;
SET B;
SET TEMP2;
NEW_LEN_0=COL1+10;
NEW_LEN=PUT(NEW_LEN_0,$32.);
DEF_LEN=CAT(NAME,' ','$',COMPRESS(NEW_LEN));
RUN;
PROC SQL NOPRINT;
SELECT DEF_LEN INTO: DEF_LEN SEPARATED BY ' ' FROM TEMP2;
QUIT;
DATA &OUT_TABLE;
LENGTH &DEF_LEN;
SET &IN_TABLE;
RUN;
%MEND;
调用宏：
OPTIONS NOCENTER LS=MAX PS=MAX SASMSTORE=SASUSER MSTORED MAUTOSOURCE;
LIBNAME S '.DATA';
%M_CHANGE_LENGTH(S.A,S.CHANGE_A);
/*第一个参数是原数据集，第二个参数是改变长度的数据集*/