I find that pack is easier to understand with code examples that pipe the packed string into hexdump. The last snippet is just packing the ASCII character set.

$ perl -e 'print pack q{H*}, sprintf q{%2x}, 0x3a;' | hexdump -C
00000000  3a                                                |:|
00000001

[download]
$ perl -e '
print pack q{(H*)*},
   map { sprintf q{%2x}, $_ } 0b111010, 072, 58, 0x3a;' | hexdump -C
00000000  3a 3a 3a 3a                                       |::::|
00000004

[download]
$ perl -e '
print pack q{(H*)*},
   map { sprintf q{%2x}, $_ } 0 .. 127;' | hexdump -C
00000000  00 01 02 03 04 05 06 07  08 09 0a 0b 0c 0d 0e 0f  |.........
+.......|
00000010  10 11 12 13 14 15 16 17  18 19 1a 1b 1c 1d 1e 1f  |.........
+.......|
00000020  20 21 22 23 24 25 26 27  28 29 2a 2b 2c 2d 2e 2f  | !"#$%&'(
+)*+,-./|
00000030  30 31 32 33 34 35 36 37  38 39 3a 3b 3c 3d 3e 3f  |012345678
+9:;<=>?|
00000040  40 41 42 43 44 45 46 47  48 49 4a 4b 4c 4d 4e 4f  |@ABCDEFGH
+IJKLMNO|
00000050  50 51 52 53 54 55 56 57  58 59 5a 5b 5c 5d 5e 5f  |PQRSTUVWX
+YZ[\]^_|
00000060  60 61 62 63 64 65 66 67  68 69 6a 6b 6c 6d 6e 6f  |`abcdefgh
+ijklmno|
00000070  70 71 72 73 74 75 76 77  78 79 7a 7b 7c 7d 7e 7f  |pqrstuvwx
+yz{|}~.|
00000080

[download]

I hope that you also find these examples helpful.

Cheers,

JohnGG

In reply to Re: print packed string by johngg
in thread print packed string by lightoverhead

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