c-gcc, 74 bytes

Result

WA

Code [DL]

f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}

stdin

1357435271368815039695803410067908377844828887478955551011508528081492168462153443708600911346453972

stdout

stderr

/volume/CODE.c:1:1: error: ‘f’ declared as function returning a function
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
 ^
/volume/CODE.c:1:1: warning: return type defaults to ‘int’ [-Wimplicit-int]
/volume/CODE.c: In function ‘f’:
/volume/CODE.c:1:19: error: ‘a’ undeclared (first use in this function)
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
                   ^
/volume/CODE.c:1:19: note: each undeclared identifier is reported only once for each function it appears in
/volume/CODE.c: At top level:
/volume/CODE.c:1:29: warning: return type defaults to ‘int’ [-Wimplicit-int]
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
                             ^
/volume/CODE.c: In function ‘main’:
/volume/CODE.c:1:29: warning: type of ‘p’ defaults to ‘int’ [-Wimplicit-int]
/volume/CODE.c:1:29: warning: type of ‘s’ defaults to ‘int’ [-Wimplicit-int]
/volume/CODE.c:1:39: warning: implicit declaration of function ‘gets’ [-Wimplicit-function-declaration]
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
                                       ^
/volume/CODE.c:1:47: warning: implicit declaration of function ‘qsort’ [-Wimplicit-function-declaration]
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
                                               ^
/volume/CODE.c:1:64: warning: implicit declaration of function ‘puts’ [-Wimplicit-function-declaration]
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
                                                                ^
/volume/CODE.c: In function ‘f’:
/volume/CODE.c:1:1: warning: control reaches end of non-void function [-Wreturn-type]
 f()(int*a){return*a-*1[&a];}main(p,s){gets(s);qsort(s,100,1,f);puts(s);}
 ^
/home/esolang/bin/c-gcc: line 4: /tmp/code: No such file or directory

strace