foo.c:10:6: warning: return type of 'main' is not 'int' [-Wmain]
foo.c: In function 'main':
foo.c:21:2: error: 'for' loop initial declarations are only allowed in C99 mode
foo.c:21:2: note: use option -std=c99 or -std=gnu99 to compile your code
foo.c:25:11: error: redefinition of 'i'
foo.c:21:11: note: previous definition of 'i' was here
foo.c:25:2: error: 'for' loop initial declarations are only allowed in C99 mode
foo.c:32:6: error: redeclaration of 'i' with no linkage
foo.c:25:11: note: previous definition of 'i' was here
foo.c:32:10: warning: unused variable 'l' [-Wunused-variable]