$ ls
fileio.cpp   list.cpp     phone.cpp    scrio.cpp    test.c
fileio.h     list.h       phone.h      scrio.h
$ cat *.cpp *.h *.c > sum.cpp
$ ./showheaders < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"

Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$
$ ./showheaders -uc < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"

Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$
$ ./showheaders -cu < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"

Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$
$ ./showheaders -u -c < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"

Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$
$ ./showheaders -c -u < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"

Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$
$ ./showheaders -u < sum.cpp
Uncommented header filenames:
<stdio.h>
<string.h>
<malloc.h>
"phone.h"
"fileio.h"
"scrio.h"
"list.h"
<string.h>
<curses.h>
"phone.h"
"scrio.h"
"fileio.h"
<curses.h>
<stdio.h>
<stdarg.h>
"phone.h"
"scrio.h"
"list.h"
"phone.h"
<curses.h>
<string.h>
<math.h>
"queue.h"
$
$ ./showheaders -c < sum.cpp
Commented header filenames:
"list2.h"
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>
$ ./showheaders < test.c
Uncommented header filenames:
<string.h>
<math.h>
"queue.h"

Commented header filenames:
<stdio.h>
<stdio.h>
<stdio.h>
"list.h"
<stdio.h>