%symdel  <宏变量名>;     删除宏变量

删除输入输出格式
PROC DATASETS lib=work;
MODIFY dsn;
FORMAT _all_;
INFORMAT _all_;
RUN;
QUIT;

*work is the library name;
*mention the name of the SAS dataset, whose formats and informats needs to be removed in the MODIFY statement;
* format _all_ will delete all the formats in the SAS dataset.

非常感谢！！！

2# myzhang1982

试了一下，删除宏变量没有问题，但是删除输入输出格式可能不是我的意思，你那种方法只是对数据集变量的格式进行修改；
例如：我用proc format cntlin＝a; run;定义了一个输出格式，名称为“fmt_a”。现在想把fmt_a的自定义格式删除，避免被别的误引用，该怎么做？！
多谢了！



2# myzhang1982

The local macro variables live with their scopes. You only need to take care of GLOBAL ones. Here is simple one to 'kill' them all.


%let a=a; %let b=b;    %let c=c;
%put >>>&a &b &c<<<;


proc sql noprint;
DESCRIBE TABLE dictionary.macros;
select name into: mvarlist separated by ' '
from  dictionary.macros
where scope ='GLOBAL' and not index(name,'SYS') ;
quit;

%put &mvarlist;

%symdel  &mvarlist     ;
%symdel mvarlist;

%put _all_;
*********************************************************************************
You can use proc catalog to kill all format/informat were defined in a library as,

proc format ;
value $wert
s=1
r=2
other=0
;
run;

  data t1;
    a='s';
    put a $wert.;
run;

proc catalog cat=work.formats kill;
run;

data t1;
    a='s';
    put a $wert.;
run;

非常感谢！祝快乐！
5# bobguy