# Pack format 'H' when the packee has insufficient and odd digits

**URL:** <https://www.ruby-forum.com/t/pack-format-h-when-the-packee-has-insufficient-and-odd-digits/154944>\
**Category:** Development\
**Created:** [December 5, 2008, 12:39pm UTC](https://www.ruby-forum.com/t/pack-format-h-when-the-packee-has-insufficient-and-odd-digits/154944 "2008-12-05T12:39:23Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Yugui\_SYuki\_S.S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/dec6dc/32.png) [@Yugui\_SYuki\_S.S](https://www.ruby-forum.com/u/Yugui_SYuki_S.S)\
**Post date:** [December 5, 2008, 12:39pm UTC](https://www.ruby-forum.com/t/pack-format-h-when-the-packee-has-insufficient-and-odd-digits/154944/1 "2008-12-05T12:39:23Z")

</div>

Yuguie$B$G$9!#e(B

pack format  
'H’e$B$K$\*$$$F!“Ho%Q%C%/%G!\<%?$,e(B16e$B?J$G4q?t7e$G$”$k\>l9g!"@8@.$5e(B  
e$B$l$k%P%$%HNs$ND9$5$K!V%8%c%s%W!W$,8+$i$l$^$9!#e(B

[“FFF”].pack(“H1”) #=\> “\xF0”  
[“FFF”].pack(“H2”) #=\> “\xFF”  
[“FFF”].pack(“H3”) #=\> “\xFF\xF0”

[“FFF”].pack(“H4”) #=\> “\xFF\xF0\x00”  
[“FFF”].pack(“H5”) #=\> “\xFF\xF0\x00”  
[“FFF”].pack(“H6”) #=\> “\xFF\xF0\x00\x00”

1.8.7-p72e$B$He(Btrunke$B$GF1$8?6$k$^$$$r3NG’$7$^$7$?!#e(B

H4e$B$N\>l9g$OB-$j$J$$Bhe(B4e$B%K%V%k$re(B0e$B$H8+$J$7$F!"e(B2e$B%P%$%HL$N2\<0L%K%V%k$K=\<$F$ke(B  
e$B$N$,\<+A3$J5$$,$7$^$9!#$D$^$j!"e(B

[“FFF”].pack(“H4”) #=\> “\xFF\xF0”  
[“FFF”].pack(“H5”) #=\> “\xFF\xF0\x00”  
[“FFF”].pack(“H6”) #=\> “\xFF\xF0\x00”

e$B8=\>u$N?6$k$^$$$O0U?^$5$l$?$b$N$G$7$g$&$+e(B?

---

<div class="post-metadata">

**Author:** ![Yugui\_SYuki\_S.S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/dec6dc/32.png) [@Yugui\_SYuki\_S.S](https://www.ruby-forum.com/u/Yugui_SYuki_S.S)\
**Post date:** [December 8, 2008, 9:55am UTC](https://www.ruby-forum.com/t/pack-format-h-when-the-packee-has-insufficient-and-odd-digits/154944/2 "2008-12-08T09:55:15Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:37283] pack format ‘H’ when the packee has  
insufficient and odd digits”  
on Fri, 5 Dec 2008 20:32:51 +0900, “Yugui (Yuki S.)”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|pack format 'H’e$B$K$\*$$$F!“Ho%Q%C%/%G!\<%?$,e(B16e$B?J$G4q?t7e$G$”$k\>l9g!"@8@.$5e(B  
|e$B$l$k%P%$%HNs$ND9$5$K!V%8%c%s%W!W$,8+$i$l$^$9!#e(B

|H4e$B$N\>l9g$OB-$j$J$$Bhe(B4e$B%K%V%k$re(B0e$B$H8+$J$7$F!"e(B2e$B%P%$%HL$N2\<0L%K%V%k$K=\<$F$ke(B  
|e$B$N$,\<+A3$J5$$,$7$^$9!#e(B

|e$B8=\>u$N?6$k$^$$$O0U?^$5$l$?$b$N$G$7$g$&$+e(B?

e$B0U?^$7$?$b$N$G$O$J$$$G$9!#$3$3$Oe(BPerle$B$K9g$o$;$k$Y$-$@$H;W$$$^e(B  
e$B$9!#$A$J$\_$K:#D4$Y$?$H$3$m$G$Oe(BPerle$B$G$N7k2L$ND9$5$Oe(B

# perl -le ‘print length(pack(“H1”, “FFF”))’

1

# perl -le ‘print length(pack(“H2”, “FFF”))’

1

e$B0J2\<!"e(BH3=\>2, H4=\>2, H5=\>3, H6=\>3, H7=\>4, H8=\>4, H9=\>5 e$B$HB3$-e(B  
e$B$^$9!#e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```