RTFM background:

http://perldoc.perl.org/functions/sprintf.html
Size:  h interpret integer as C type "short" or "unsigned short"
%u    an unsigned integer, in decimal
%hu -> unsigned  C type "short"
This is Exactly the contents of the Perl variable as verified by C

##</code><code>##

Test program ouput:
Running C:\bin\bb.pl   Wed Jan  6 13:26:28 2016
Perl: Pack number 7360 into uint16 and dump to file pack.test.dat

hex_dec_bin_dump.exe
File pack.test.dat is 2 bytes long
Read 2 Bytes from pack.test.dat
Int 7360, uint16 7360, hex 0X1CC0, float 7360.0000, binary 1110011000000
BAD_PRINT, Show uint16 as chars: 7360 != +?

Argument "+^\" isn't numeric in printf at C:\bin\bb.pl line 179, <FOO> line 168.

Number 7360 Packed into 'S': h 0, d 0, hu 0, b 0, s +?

##</code><code>##

Perl Code:
sub perl_pack_print()  {
    $ofn='pack.test.dat';  # Output file Name
    $xres=7360;            # X Resolution
    $pxres=pack("S", $xres);  # Xres Packed into USHORT
    open(O, ">$ofn");  binmode O;
    print(O "$pxres");  close O;
    print("Perl: Pack number $xres into uint16 and dump to file $ofn\n");

    # Verify that Perl wrote the correct data to disk
    system("hex_dec_bin_dump.exe $ofn");

    # See if Perl can print the '%hu' it just wrote to disk
    printf("Number $xres Packed into 'S': h %x, d %d, hu %hu, b %b, s %s\n",
        $pxres, $pxres, $pxres, $pxres, $pxres);
}

##</code><code>##

C dump verification code:
// Dump given file as hex, dec, float, string...
//
// gcc -Ofast -ffast-math -m64 -march=sandybridge  -funroll-loops -fopenmp -flto -lm  c:/bin/hex_dec_bin_dump.c -o c:/bin/hex_dec_bin_dump.exe

#include "bpbfct.c"

void main(int argc, char *argv[])  {
FILE *ifp;  // FILE pointers to Output and Input file
struct stat statbuf;  // STAT function buffer         
long bread=-1;  // Bytes Read
int fsize=0;    // File size from STAT()
uint16_t usbuf[99];    // Unsigned Short BUFfer
uint8_t *char_8_ptr;   // Bytes to bisect/mutilate short
char bitb[254]={ 0 };  // Bit Buffer. Should hold ANY integer
char ifn[255]={ 0 };

    strcpy(ifn, argv[1]);   // Input File Name arg
    stat(ifn, &statbuf);    // Stat the file to get its size
    fsize=statbuf.st_size;  // File size in bytes for .raw (RGB?) file
    printf("\n%s\nFile %s is %d bytes long\n", argv[0], ifn, fsize);

   
    ifp=fopen(ifn, "rb");                     // Open input file in binary
    bread=fread((void *)usbuf, 1, 999, ifp);  // Read argued file
    printf("Read %d Bytes from %s\n", bread, ifn);
    printf("Int %d, uint16 %hu, hex 0X%04X, float %.4f, binary %s\n",
        usbuf[0], usbuf[0], usbuf[0], (float)usbuf[0],
        itoa(usbuf[0], (char *)(&bitb), 2));
    char_8_ptr=(uint8_t *) usbuf;  // Cast ushort buf to uShortER
    printf("BAD_PRINT, Show uint16 as chars: %hu != %c%c\n\n",
        usbuf[0], char_8_ptr[0], char_8_ptr[1]);
    exit(0);
}  // End Main().

##</code><code>##

	$hdr[16]=pack("S", 7360);
	$hdr[22]=pack("S", 4912);
	printf("FIXED?  HDR[16]=$hdr[16], HDR[22]=$hdr[22]\n");

##</code><code>##

Read 1376 B from d:/pic/misc/gray.1376b.3689x2462.hdr
RGB[16]=3689, [22]=2462
FIXED?  HDR[16]=&#9492;&#8735;, HDR[22]=0&#8252;

##</code><code>##

	@hdr=unpack("S*", $hdr);  # RAW RGB Unsigned Short array
	printf("PrInTf:: RGB[16]=%hu, [22]=%d\n", $hdr[16], $hdr[22]);
	print ("pRInT :: RGB[16]=$hdr[16], [22]=$hdr[22]\n");  =>
PrInTf:: RGB[16]=3689, [22]=2462
pRInT :: RGB[16]=3689, [22]=2462

##</code><code>##

	open(H, "<$hfn");  binmode H;
	printf("Read $bread B from $hfn\n");
	@hdr=unpack("S*", $hdr);  # RAW RGB Unsigned Short array

##</code><code>##

printf("FIXED?  HDR[16]=$hdr[16], HDR[22]=$hdr[22]\n");  =>
FIXED?  HDR[16]=&#9492;&#8735;, HDR[22]=0&#8252;