/in/foo.c: In function 'main':
/in/foo.c:5:10: warning: right-hand operand of comma expression has no effect [-Wunused-value]
    5 | for(i=100,i<1000,i++)
      |          ^
/in/foo.c:5:21: error: expected ';' before ')' token
    5 | for(i=100,i<1000,i++)
      |                     ^
      |                     ;
/in/foo.c:5:21: error: expected expression before ')' token
/in/foo.c:6:3: error: 'a' undeclared (first use in this function)
    6 |  {a=i%100;
      |   ^
/in/foo.c:6:3: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:7:3: error: 'b' undeclared (first use in this function)
    7 |   b=(i/10)%10;
      |   ^
/in/foo.c:8:3: error: 'c' undeclared (first use in this function)
    8 |   c=i%10;
      |   ^